Johns Hopkins Malaria Minute: Recent Episodes
Johns Hopkins Bloomberg School of Public Health
Impactful malaria science, and the trailblazers leading the fight. A podcast from the Johns Hopkins Malaria Research Institute.
Professor Jane Carlton is director of the Johns Hopkins Malaria Research Institute. Dr. Chris Smith of the Naked Scientists interviews Jane about her research, her career and the future of malaria.
In sub-Saharan Africa, mothers often carry their babies on their backs in colorful cotton wraps called lesu. Could treating these wraps with insecticide help prevent malaria? Dr. Ross Boyce discusses a groundbreaking study in Uganda showing that permethrin-treated wraps significantly reduce malaria in infants – and further, what this could mean for protecting the youngest and most vulnerable children from this often fatal disease.
A new study in rural western Uganda finds that treating baby-carrying cloths, or lesu, with an insecticide with modest repellent effect significantly reduces malaria infections in young children.
Transcript
In many parts of sub-Saharan Africa, mothers carry their young children on their backs in colorful cotton wraps called lesu. Could treating these cloths with insecticide reduce malaria transmission?
A study published in the New England Journal of Medicine explored this question in rural western Uganda, where malaria is transmitted year-round. Researchers enrolled 400 mothers with children aged six to 18 months.
Using a blinded randomized placebo-controlled trial design, half received lesu treated with permethrin, a commonly-used insecticide. The other half received untreated cloths. All participants also received insecticide-treated bed nets.
Every two weeks for 24 weeks, the mothers and children visited local health centers to check for fever and undergo malaria testing. The results were striking: children carried in permethrin-treated lesu represented 66% fewer malaria cases – 0.73 cases per 100 people compared with 2.13 in the control group.
The findings suggest that insecticide-treated lesu – much like treated bed nets – could offer an effective new tool particuarly against outdoor biting for a highly vulnerable population - children under 5 years of age - in sub-Saharan Africa.
Source
Permethrin-Treated Baby Wraps for the Prevention of Malaria [NEJM]
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Too much can kill the mosquito — too little can also kill it. But the right amount can strengthen the mosquito's defenses and stop malaria transmission. Today, the Goldilocks dose. Emma Camacho shares how a natural compound called L-DOPA strengthens mosquitoes' defenses at just the right concentration, revealing a new way to block malaria transmission.
Feeding mosquitoes L-DOPA can either strengthen their defences against malaria or shorten their lifespan — showing that in vector control, the dose makes the difference
Transcript
As with all medicine, the dose determines whether something helps or harms.
Researchers recently looked at a substance commonly found in mosquito habitats that might form part of their diet. It’s called L-3-4-dihydroxyphenylalanine, or L-DOPA. Mosquitoes use it as a source of melanin.
At low doses – up to a concentration of 2% – L-DOPA was toxic to mosquitoes and reduced the number of malaria parasites they carry in a dose-dependent manner. At higher doses, toxicity was stronger and the mosquitoes’ rates of survival decreased, demonstrating what’s known as a biphasic dose response.
These findings offer two potential strategies for L-DOPA in malaria control. Low doses fed to mosquitoes in water could improve their defences against the parasite, thereby reducing onward transmission to humans. Higher doses could be used to kill mosquitoes or reduce their life span, particularly if used in a sugar bait.
These strategies align with the need for cost-effective, sustainable and eco-friendly vector control methods. For L-DOPA, it all comes down to the dose.
Source
Dietary L-3,4-dihydroxyphenylalanine (L-DOPA) augments cuticular melanization in Anopheles mosquitos reducing their lifespan and malaria burden
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
How do you turn vast amounts of genetic data into actionable insight – efficiently and accurately? Professor Bryan Greenhouse of UCSF discusses a series of “hackathons” at the Johns Hopkins Malaria Research Institute (JHMRI) that bring together scientists from around the world to tackle one of the biggest challenges in malaria research: analyzing parasite genetics. By developing open-source tools, workflows, and training resources, these collaborations are making cutting-edge analysis more accessible to labs and public health programs everywhere.
In Kwale, Kenya, where bed nets alone can’t stop malaria, researchers are testing ivermectin – a drug long used to treat parasitic infections – as a new way to kill mosquitoes. Trials show a 26% drop in malaria cases and added benefits against other mosquito-borne diseases, suggesting ivermectin could be a scalable, community-driven tool in the fight against insecticide resistance.
With Carlos Chaccour (researcher at the Navarra Center for International Development) and Joseph Mwangangi (scientist at KEMRI)
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
A new study in Kenya shows that mass drug administration of ivermectin safely reduced malaria cases by 26%, offering a promising supplement to insecticide-based prevention.
Transcript
Bed nets and insecticides are commonly used to prevent malaria transmission. But insecticide resistance is making those tools less effective.
There’s a growing interest in ivermectin, an antiparasitic drug normally used to treat neglected tropical diseases such as river blindness or scabies, that is also capable of killing the Anopheles mosquitoes that transmit malaria.
In a new study in the New England Journal of Medicine, researchers from ISGlobal, an institute in Barcelona, investigated whether ivermectin given to at-risk populations en masse – in a policy of ‘mass drug administration’ – might supplement the use of insecticides to reduce malaria transmission.
In Kwale, a coastal county in Kenya where malaria is present year-round, nearly twenty-nine thousand people took part.
Half were given ivermectin at 400μg per kilogram of bodyweight. The other half were given 400mg of albendazole, not an antimalarial drug, but an anti-worming drug comparable to ivermectin.
Each group took the drug once a month for three months. The study looked at both the efficacy and safety of the two interventions.
Both drugs proved safe, but ivermectin had a greater impact, leading to a 26% reduction in malaria cases – higher than the 20% efficacy benchmark set by the World Health Organization.
Source
Source: Ivermectin to Control Malaria — A Cluster-Randomized Trial [NEJM]
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Focusing on patients in Mali, researchers examine why some children develop life-threatening complications like cerebral malaria or severe malarial anemia.
With Mark Travassos (University of Maryland School of Medicine), Mahamadou Ali Thera (University of Science Techniques and Technologies of Bamako), and Rafal Sobota (Northwestern University).
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Although severe malaria presents in different clinical forms – such as cerebral malaria or severe malarial anemia – a new study reveals that all severe cases have one thing in common: a shared inflammatory signature
Transcript
Whilst most cases of malaria are mild, some take a dangerous turn. In severe cases, the malaria parasite can overwhelm the body, disrupting the blood-brain barrier and leading to cerebral malaria, or destroying so many red blood cells that it triggers life-threatening anemia. Now, a new study has taken a closer look at this progression – from uncomplicated malaria to severe disease.
Researchers looked at three factors: Transcriptomics, the genes being expressed; proteomics, the proteins being produced; and metabolomics, the metabolites and small molecules present. Using a matched-pairs design, they compared blood samples of children with severe malaria versus children with uncomplicated disease.
The finding? Although different types of severe malaria can be distinguished by other factors, they all share a ‘common signalling pattern.’
Two proteins stood out: MMP8 and MMP9 – and those proteins are both involved, in different ways, in the breakdown of the extracellular matrix – the scaffolding between cells. The finding gives researchers new clues into how malaria becomes deadly, and may open the door to better-targeted treatments – or even a vaccine against severe malaria - in the future.
Source
A shared inflammatory signature across severe malaria syndromes manifested by transcriptomic, proteomic and metabolomic analyses [Nature Communications]
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Dr. Alexandra Probst discusses a breakthrough in malaria prevention: bed nets coated with anti-parasitic drugs that stop transmission by curing infected mosquitoes.
With Alexandra Probst, former graduate student at Harvard University.
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
How next-generation bed nets could stop malaria by killing the parasites inside mosquitoes, not just the mosquitoes themselves.
Transcript
Bed nets have long been a cornerstone of vector control. Coated with insecticide, they serve a dual purpose: preventing bites and killing mosquitoes. But what if those nets could do more – not only kill the mosquitoes, but for those they don’t kill because of increasing insecticide resistance, at least kill the parasites hidden inside them?
Researchers assembled a library of antiparasitic compounds active against the form of the parasite in the mosquito midgut. They identified 81 promising compounds, some of which were already in clinical development. Of those, 22 were found to be effective against these early stages of parasite development in the mosquito and, therefore, capable of preventing onward transmission.
One class of compound stood out: ELQs, or endochin-like quinolones. These could be absorbed through the mosquito’s legs in tests, therefore viable for use in a mosquito net. The researchers suggest that ELQs could offer a promising new strategy for malaria control, working alongside traditional methods to reduce malaria cases and deaths.
Source
In vivo screen of Plasmodium targets for mosquito-based malaria control (Nature)
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
The extent to which malaria vaccines reduce cases and deaths is a key consideration. But there’s another factor, too.
with Dr. Lemu Golassa, Head of Medical Parasitology at Addis Ababa University.
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
A recent study in Ethiopia reveals that local malaria parasite strains differ genetically from those targeted by current vaccines, potentially reducing their effectiveness.
Transcript
The recent introduction of two malaria vaccines in sub-Saharan Africa represents a major success in global health, and the culmination of decades of research and development. The two jabs – RTS,S and R21 – target a protein on the surface of the malaria parasite as it enters the skin, called the circumsporozoite protein, or CSP. The vaccines are based on a specific form of CSP. The challenge is that there are many forms of CSP – called haplotypes – across regions. Vaccine efficacy, therefore, may in part depend on how closely local CSP haplotypes match those used to develop the vaccine. If they’re a close match, the vaccine should work well, but if there’s a mismatch, the vaccine may be less effective.
A recent study in Ethiopia collected blood samples from malaria-infected children over the age of five from three health centres in different parts of the country. Of the 120 blood samples collected, CSP was successfully sequenced in 85. Whilst there was little variation in samples from the same region, there was significant variation between regions, highlighting the genetic polymorphism of CSP. Importantly, none of the Ethiopian CSP haplotypes matched the vaccine haplotype, indicating the jabs may not achieve optimal efficacy in the country.
Source
Unveiling mismatch of RTS S AS01 and R21 Matrix M malaria vaccines haplotype among Ethiopian Plasmodium falciparum clinical isolates (Scientific Reports)
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
The podcast explores the importance of advocacy for malaria research and control. It follows over 120 advocates gathering in Washington, DC, as part of the ‘United to Beat Malaria’ campaign, urging Congress to continue supporting global malaria efforts.
Key topics include:
- The US President’s Malaria Initiative (PMI), founded in 2005, which provides bed nets, test kits, and treatments to combat malaria
- The role of global partnerships, including the Global Fund, in distributing resources efficiently.
- How Uganda’s malaria response is supported by international funding for the dissemination of key public health interventions.
- The importance of sustained funding for malaria research, with US agencies like NIH, CDC, and PMI contributing to vaccine development and disease surveillance.
Featuring: Margaret Reilly McDonnell (United to Beat Malaria), Dr David Walton (formerly PMI), Dr Jimmy Opigo (Uganda National Malaria Control Program), Jamie Bay Nishi (ASTMH) and Ed Royce (former House Foreign Affairs Committee (HFAC) Chairman).
With a shortage of entomologists in malaria-endemic regions, could AI fill the gap? We explore VectorCam, an offline tool powered by a Convolutional Neural Network that aims to support local vector surveillance.
with Dr. Soumya Acharya and Sunny Patel of Johns Hopkins University.
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Can AI identify mosquito species? VectorCAM, a pocket-sized device, uses machine learning to differentiate species with 95% accuracy, enhancing malaria surveillance efforts
Transcript
Not all mosquitoes are created equal. Of the more than three thousand species, only a limited number of the Anopheles genus can transmit malaria. Even within that subset, subtle physiological differences affect how malaria spreads. Some mosquitoes prefer to bite indoors, while others outdoors. Some need large bodies of water to breed, while others only need a small puddle. Distinguishing these species is critical for effective malaria control—whether using bed nets, indoor spraying, or outdoor larval management. But identifying them by eye takes expert, entomological knowledge. Could AI help? The VectorCAM team at Johns Hopkins is working on just that. Their pocket-sized device uses a small light and magnifying lens, allowing a phone camera to capture close-up images of mosquitoes placed on slides. With up to 95% accuracy, it can identify mosquito species based on morphology in seconds. The hope is that VectorCAM will help health teams better understand mosquito populations, paving the way for more targeted and relevant malaria control efforts.
Source
Towards transforming malaria vector surveillance using VectorBrain: a novel convolutional neural network for mosquito species, sex, and abdomen status identifications (Scientific Reports)
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
For decades, insecticides have shielded us from malaria—but cracks are showing. Resistance is spreading, and environmental concerns are growing. Could a simple pouch of fruit juice with a powerful secret be the breakthrough we need?
with George Dimopoulos of the Johns Hopkins Malaria Research Institute
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
One of the main ways of controlling malaria is to reduce mosquito populations through insecticides. But the mosquitoes are developing resistance, making most insecticides less effective. What if the answer lies beneath our feet?
Transcript
One of the main ways of controlling malaria is to reduce mosquito populations through insecticides. But the mosquitoes are developing resistance, making most insecticides less effective. We need new vector control interventions – what if the answer lies beneath our feet? Researchers from the Dimopoulos Group at the Johns Hopkins Malaria Research Institute have turned to an unexpected source of inspiration—soil. They’ve produced a natural biopesticide, derived from a type of bacteria found in soil called Chromobacterium. When you deliver this biopesticide through a sugar bait – which lures the mosquitoes to feed on it – it kills the mosquitoes, regardless of their resistance to insecticides. Additionally, at non-lethal doses, Chromobacterium can enhance the effectiveness of other insecticides, acting as a synergist, as well as making mosquitoes incapable of finding a human to feed on. These findings were first demonstrated in the lab, but have now been confirmed in enclosed field trials in Burkina Faso. It's hoped that this naturally-occurring insecticide could support vector control efforts to curb disease transmission.
Source
Chromobacterium biopesticide overcomes insecticide resistance in malaria vector mosquitoes (Science)
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
The prevention of malaria depends upon multiple layers of interventions that work together to reduce cases and deaths. But what makes someone decide to sleep under a bed net, or apply an insecticidal cream? What makes one person take up more interventions than another? How influential are government-accredited health experts versus friends and family?
With András Vörös, an Associate Professor in Quantitative Methods at the University of Birmingham and Elisa Bellotti, a Senior Lecturer in Sociology at the University of Manchester.
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Malaria prevention depends on the adoption of multiple behaviors – like sleeping under a bednet and wearing clothes that cover the skin. Researchers find that conversations with people in one’s own social circle are the strongest factors that influence behavior uptake.
Transcript
Malaria prevention depends on the adoption of multiple behaviors – like sleeping under a bednet and wearing clothes that cover the skin – to reduce exposure to infectious mosquitoes. Theories of ‘social influence’ are often used to explain the uptake of single behaviors, in which an individual's relationship to others explains their adoption of certain behaviors. Yet, to better understand the uptake of different malaria prevention behaviors in a broader context, researchers looked beyond just social ties to consider the influence of behavior carry-over: where an individual who already adopts one prevention behavior is more likely to adopt another. Researchers applied this multi-level social network analysis to structured interviews from 10 villages in Northeast India, all conducted at a single point in time. They found that network exposure – talking to someone in your network who adopts a certain behavior – was the most important and consistent factor in explaining behavior uptake. This was more influential than individual behavior carry-over (which had no effect), existing village behavior patterns, or ties with health workers (which had minimal effect). This reinforces the importance of social discussion as the most significant factor in determining behavior uptake.
Source
A multilevel social network approach to studying multiple disease-prevention behaviors (Nature Scientific Reports)
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Today, the discovery of antibodies targeting a new region of the malaria parasite that could serve as a promising target for drugs and vaccines.
Scientists discover new antibodies - a promising target for clinical exploration.
Transcript
The currently licenced malaria vaccines and monoclonal antibodies all target a well-known region of the same malaria protein. That protein – the circumsporozoite protein, commonly known as CSP – covers the surface of the parasite as it enters the human skin through a mosquito bite. By targeting CSP, the vaccines aim to stop each malaria parasite in its tracks. But what about other proteins on the sporozoite - the parasite form injected into the blood by the mosquito - or other regions of the CSP protein? In a recent study, scientists screened plasma from malaria-infected individuals for immune responses against sporozoites. Many had developed antibodies against these well-known regions of CSP, but some had developed antibodies targeting a different region of the sporozoite surface. Out of ten new antibodies isolated from these individuals, several were functional – inhibiting the development of later parasite stages that occur in the liver and preventing sporozoite infection in a mouse model of malaria. However, they were targeting a different region of CSP that was only uncovered after processing by the sporozoite. This new region – called pGlu-CSP – is, the authors say, a site of vulnerability and a promising target for future clinical exploration.
Source
Protective antibodies target cryptic epitope unmasked by cleavage of malaria sporozoite protein (Science)
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
We focus on drug resistance and the troubling news that the frontline drug against malaria, artemisinin, is failing due to resistant parasites in severe cases of malaria, and how the collective efforts of drug development – and the data produced – could be used to build an AI chatbot capable of predicting resistance before it strikes.
With Robert Opoka and Elizabeth Winzeler.
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Researchers search for ways to predict antimalarial drug resistance and identify more effective drug combinations.
Transcript
The front-line treatment for malaria is typically a combination of drugs called artemisinin-based combination therapy. Resistance to treatment has already been reported in mild cases of malaria, but now, for the first time, it’s also being reported in severe cases of malaria. Severe malaria cases are more likely to end in a fatal outcome, so drug resistance in these scenarios poses a risk to human life. To try and stay one step ahead of resistance, researchers tested compounds and combed through publications to identify 118 compounds active against over 700 parasite clones to see how the parasites evolve under pressure, and to identify mutations in the parasite genome likely to be associated with drug resistance. They confirmed that Plasmodium falciparum – the deadliest and most prevalent species of the malaria parasite – evolves relatively easily, with mutations that affect the drug’s mechanism of action and which move through the population. The hope is that this dataset of drug resistance markers could provide an ‘early warning system’ – to predict drug resistance in the field and to identify a more effective drug combination.
Source
Artemisinin Partial Resistance in Ugandan Children With Complicated Malaria (JAMA)
Systematic in vitro evolution in Plasmodium falciparum reveals key determinants of drug resistance (Science)
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
The World Health Organization has today released its annual World Malaria Report. Here are the takeaways.
Transcript
The World Health Organization has today released its annual World Malaria Report. Here are the takeaways. Since the turn of the century, the global malaria community has averted over 2.2 billion malaria cases and 12.7 million deaths, with over a million deaths prevented in 2023 alone. Yet, despite significant progress, major gaps remain. In 2023, there were 263 million malaria cases globally, up 11 million from the year before, and nearly the same number of deaths. This means we’re off course against key WHO targets, with the case rate amongst at-risk populations three times higher than hoped, and a funding gap of over $4bn. It’s hoped that a ‘Big Push’ of political and capital commitment could accelerate efforts against the disease, help overcome drug and insecticide resistance, and improve access to new bed nets, drugs, and vaccines. But, as ever, this is dependent on funding, political will, and as this year’s report notes, a special focus on equity. There’s a need to disaggregate data to reveal the nuances of malaria transmission and understand how the disease intersects with gender equality, health equity and human rights.
Source
World malaria report 2024
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
An innovative, non-invasive diagnostic tool that could revolutionize malaria testing, with the potential to be built into wearable devices.
In this extended episode of the Johns Hopkins Malaria Minute, we ask:
- What are the limitations of current malaria diagnostic methods?
- How is a 'cytophone' - and what makes it innovative?
- Why is the detection of hemozoin significant in malaria diagnostics?
- How does interdisciplinary collaboration contribute to technological innovation?
With Sunil Parikh, Vladimir Zharov and Yap Boum
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Using lasers and ultrasound, the ‘cytophone’ detects a key byproduct of all malaria parasites.
Transcript
Among the most commonly used malaria diagnostic tests is the rapid diagnostic test (RDT), which detects malaria antigens from a drop of blood. Whilst RDTs are small and cheap, they're invasive and new strains of the parasite have evolved that can escape RDT diagnosis. Now, engineers have developed new diagnostic technology – a cytophone – which doesn’t require a blood draw. About the size of a desktop printer, the cytophone uses lasers and ultrasound to detect infected red blood cells in the vein on a patient’s hand or forearm. The cytophone works by detecting hemozoin, a byproduct of all malaria parasites from their consumption of hemoglobin for energy. When hemozoin absorbs a certain amount of the laser energy, it heats up and expands, generating ultrasound waves that indicate malaria infection within the red blood cell. In a trial of 20 adults in Cameroon with symptomatic malaria, the cytophone prototype performed as well as current point-of-care diagnostic methods.
Source
Noninvasive in vivo photoacoustic detection of malaria with Cytophone in Cameroon
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Today, how DNA from a single patient in Ethiopia can shed light on the big picture of malaria.
- Why is Plasmodium vivax significant in malaria research, especially in Ethiopia?
- How does genomic sequencing contribute to understanding and controlling malaria?
- How are advances in sequencing technology influencing malaria research?
With Jane Carlton, Delenasaw Yewhalaw, and Francisco Callejas Hernandez
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
'Comparative genomics' helps identify genes that can serve as targets for future drugs and vaccines.
Transcript
Not all parasites are alike. Genetic mutations mean that malaria parasites evolve differently in different regions – and even within the same region. One species thought to be particularly genetically diverse is Plasmodium vivax. It’s the second most common species of malaria, found in South East Asia, South America, and some parts of Africa. In Ethiopia, 20% of malaria cases are thought to be caused by P. vivax. In a new paper, scientists made a ‘reference genome’ from a sample of P. vivax in Ethiopia. They collected blood from an infected patient, extracted the DNA, and ‘read’ its fragments to form the parasite genome. This allows scientists to compare P. vivax samples across regions – and understand their similarities and differences. Importantly, this study of ‘comparative genomics’ ie comparing genomes will help identify the genes that stay the same – the conserved genes – and those which are different - the unique genes -which could serve as targets for future drugs and vaccines.
Source
Assembled genome of an Ethiopian Plasmodium vivax isolate generated using GridION long-read technology
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
The World Health Organisation has recommended two licenced malaria vaccines. Those vaccines have been a long time coming - but are they the best?
In this extended episode of the Johns Hopkins Malaria Minute, we ask:
- Why is developing a malaria vaccine so challenging?
- How does antigen variation play affect the effectiveness of malaria vaccines?
- What are transmission-blocking vaccines (TBVs), and why haven't they gained much interest despite their potential?
With Ilinca Ciubotariu, Qixin He and Giovanna Carpi.
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
A key challenge in developing a malaria vaccine is choosing which stage to target.
Transcript
A key challenge in developing a malaria vaccine is choosing which stage of the infection to target. You can target the parasite when it enters the body, multiplies in the liver and the blood, or is in the sexual stage, preparing to be picked up by a mosquito. Along with selecting the right vaccine target, it’s also important to consider how these targets naturally vary in the population. To identify the optimal target, researchers examined the genetic and structural variation of ten antigens in over 1,000 samples of malaria parasites from six African countries. Interestingly, antigens involved in human infection showed the most genetic and structural variation across countries. Transmission-blocking antigens—ones that induce antibodies in humans that disrupt the parasite’s development in the mosquito, thus preventing further transmission —were more conserved across regions. This makes transmission-blocking antigens excellent targets as standalone or multi-stage vaccines to prevent onward transmission to other people.
Source
Diversity and selection analyses identify transmission-blocking antigens as the optimal solution.
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
We share a special episode of our podcast to mark World Mosqutio Day.
World Mosquito Day, observed annually on August 20th, commemorates British doctor Sir Ronald Ross's discovery in 1897 that female Anopheles mosquitoes transmit malaria to humans. More than a century later, major advancements like genetically modifying mosquitoes—AKA gene drives—have the potential to reduce malaria cases and deaths dramatically, but not without hurdles.
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
People often talk about the 'malaria toolkit' - how might gene drives fit?
Transcript
When people talk about malaria, they often mention the 'malaria toolkit' – a set of tools, like bed nets and indoor residual spraying, that are available to help curb the spread of disease. In the past, these tools were trusty go-to's – thanks to their efficacy, scalability and cost. Like the antimalarial drugs used to prevent and treat the disease, they’re primarily aimed at protecting individuals. Yet, a new technology called gene drives – which releases and spreads genetically modified mosquitoes that can't transmit the disease – aims to protect whole communities. How might they fit into the toolkit? Dr Damaris Matoka-Muhia of the Kenya Medical Research Institute considers gene drives a potentially sustainable, long-term and cost-effective solution for malaria – especially as resistance dulls other tools. And in Kenya, there are regulations in place to support gene drive implementation. The National Biosafety Authority, already used for GM crops like cotton can be leveraged, ready to roll out this innovation in the future.
Source
How could genetic approaches be integrated in the malaria toolkit?
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Gene drives have the potential to dramatically reduce malaria cases and deaths. But the technology they’re based on is new and requires new thinking on regulation.
In this first episode of our two-part focus on gene drives, we're asking how drives work – examining the CRISPR technology behind them – and exploring the hurdles for their release, including the risks, regulations and questions of consent.
With Professor Anthony James (Univeristy of California, Irvine) and Dr John Connolly (Target Malaria)
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Gene drives are a promising tool for malaria control - how can we tell they actually work?
Transcript
Gene drives are a promising new tool for malaria control. They involve releasing genetically modified mosquitoes into the wild – mosquitoes engineered to halt the parasites from developing inside the insects, or that cause the mosquitoes to die. These GM mosquitoes are then released into new habitats. Over time and across multiple generations, the gene drive spreads, reducing malaria transmission. That’s the theory. But one fundamental question remains: how can we tell they actually work? Experts say there are three distinct measures of gene drive efficacy. First, smaller-scale trials of releases should emphasize genetic efficacy, measuring the spread and frequency of the gene drive across time and space. Then, examine entomological efficacy by measuring the density of mosquitoes or the number of parasites they carry. Finally, consider the epidemiological data, by measuring the number of malaria cases in the areas where the gene drive has been released. This approach aims to ensure that the ‘causal pathway’ of gene drives effectively reduces cases and deaths.
Source
Considerations for first field trials of low-threshold gene drive for malaria vector control
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Temperature, rainfall, and humidity determine malaria transmission - but climate change is altering each one of those variables. What might this mean for cases of the disease?
With Alex Eapen, from the ICMR (Indian Council of Medical Research) in Chennai, India.
About The Podcast The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Researchers compare the temperature of mosquito breeding spots with a decade early to examine its impact on malaria transmission.
Transcript
The effects of climate change on malaria are becoming clearer. Anopheles stephensi – an urban form of the malaria mosquito – is changing its geography, moving from Southeast Asia to parts of Africa and India. To investigate the link between temperature and malaria, between 2021 and 2022 researchers in Chennai, India placed data loggers that recorded temperature – and the daily range of temperature - in both indoor and outdoor settings. They took those measurements and compared them to nine years earlier, from 2012 to 2013. The daily temperature range of indoor asbestos structures increased from around 4 to 12 degrees Celsius — compared to a marginal increase in other structures. Importantly, an increase in temperature was associated with a decrease in the incubation period – that's the time it takes for the parasite to develop in the mosquito. With invasive mosquito species entering new areas, combined with the shorter time it takes to transmit, it's becoming more clear that rising temperatures will lead to an increase in malaria cases in certain areas – and that preparation will be key.
Source
Impact of climate change on temperature variations and extrinsic incubation period of malaria parasites in Chennai, India: implications for its disease transmission potential
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
A single protein helps malaria parasites develop in the blood and cause disease symptoms. Could inhibiting this essential protein help curb the spread of disease?
With Abhishek Kanyal and Krishanpal Karmodiya.
About The Podcast The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
A poorly studied malaria protein could serve as a key drug target to help combat the growing problem of resistance.
Transcript
A poorly studied malaria protein – Plasmodium falciparum histone deacetylase 1 – could serve as a key drug target to help combat the growing problem of resistance. The protein helps regulate the ‘intraerythrocytic’ stage of the parasite: a 48-hour cycle in which the parasite invades, replicates, and bursts free from red blood cells, causing disease symptoms. By making this protein fluorescent, researchers found that it is associated with a range of major biological functions that help the parasite progress through this stage, particularly during the ‘trophozoite’ (or mature) stage. When PfHDAC1 was overexpressed, the number of malaria parasites increased – along with the expression of other genes responsible for parasite development. Dihydroartemisinin—a key antimalarial drug—ordinarily interferes with these biological processes, but overexpression of the protein leads to reduced sensitivity and resistance. This research reveals more about the parasite lifecycle in the human body and suggests a new drug target against it.
Source
PfHDAC1 is an essential regulator of P. falciparum asexual proliferation and host cell invasion genes with a dynamic genomic occupancy responsive to artemisinin stress
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
How sickle cell disease can be a blessing and a curse. And why we need equity in genomic research and to diversify the genomes we sequence.
With Ambroise Wonkam (Johns Hopkins University).
About The Podcast The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Malaria is one of humanity’s oldest diseases – and one with which we have evolved.
Transcript
Malaria is one of humanity’s oldest diseases – and one with which we have evolved. Over time, it’s put selective pressure on our genome to respond better to its infection. Sickle cell disease is one example. It causes a defect in hemoglobin – transforming red blood cells into a banana or sickle shape – reducing the amount of oxygen transported to the body’s cells. The mutation has been around for more than 20,000 years – and is thought to originate near present-day Cameroon. But in one of the many evolutionary twists, under the right conditions, sickle cell disease can protect humans from malaria, because it makes it harder for malaria parasites to infect red blood cells. Possessing one copy is an asset, providing resistance to severe malaria, but if two copies of the mutation appear, it is a liability, leading to premature death. The evolutionary relationship between malaria endemicity and sickle cell disease is evident geographically. This complex, genetic legacy is the focus of an upcoming talk by Ambroise Wonkam at the Johns Hopkins Malaria Research Institute’s World Malaria Day symposium on April 25th.
Source
Evolutionary history of sickle-cell mutation: implications for global genetic medicine
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
On the steps of Capitol Hill, we meet the scientists bringing their scientific battle against malaria into the world of political advocacy. They join a 100+ group of advocates lobbying their members of Congress to fund critical interventions against malaria – becoming ‘malaria champions’ as well.
We ask:
- Why have they decided to join the world of political advocacy?
- How are they using their expertise to strengthen the champion’s efforts?
- What scientific message do they have to share?
With David Sullivan (Johns Hopkins University), Tracey Lamb and Jenna Reed (University of Utah) and Louisa Messenger (University of Las Nevas Nevada)
About The Podcast The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Malaria champions from 43 states gather in Washington D.C. to lobby their members of Congress about malaria.
Transcript
The malaria community is diverse. Some work on the parasites, others the mosquito. Others still focus on public health. The battle is being waged on the bench and the field. But there's another community fighting the disease on a different frontline: in the corridors and offices of Capitol Hill. This week, ‘malaria champions’ from 43 states gather in Washington DC for the annual ‘United to Beat Malaria’ conference. And this year, there’s a focus on how critical scientific research is to the fight. JHMRI’s David Sullivan reiterated that sound policy must be based on sound science. By communicating the science, scientists can help explain the significance of malaria and define policy problems – and solutions – more clearly. Because, despite reductions in cases and deaths, significant, interconnected challenges remain, including drug and insecticide resistance, the need to strengthen health systems, and the looming threat of climate change. With the United States government being the largest government donor to malaria efforts, the champions hope that by persuading their representatives to continue the fight, they can be part of the solution.
Source
United to Beat Malaria 2023 Year in Review
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Until recently, health workers were the only means to prevent and treat malaria in Odisha, India. In 2017, the state government tried a new strategy: pooling health resources into regional ‘malaria camps’.
In this podcast, we ask:
- What is the current state of malaria in Odisha, India?
- What challenges does Odisha face in malaria control, especially in hard-to-reach areas?
- What inspired the Odisha government to introduce the concept of malaria camps?
- What makes this approach encouraging and potentially translatable to regions with higher malaria endemicity, such as Africa?
With Praveen Sahu, Senior Researcher in Molecular Biology and Infectious Diseases, and Jane Carlton, Director of the Johns Hopkins Malaria Research Institute. and Jane Carlton.
About The Podcast The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Malaria in India has fallen in recent decades — but the risk is still high among hard-to-reach communities. A new study has evaluated the system of ‘malaria camps’ — in which health workers provide targeted interventions before the monsoon.
Transcript
Malaria in India has diminished in past decades — yet the risk is still high among hard-to-reach communities in forested areas that are isolated particularly during the monsoon season. To control the disease in these areas, the government has started a system of ‘malaria camps’, where health workers come to the villages to deliver key interventions, like mass screening and treatment, combined with education, intensified vector control, and maternal and child health visits. A new study has examined the effectiveness of these camps. In 15 villages in the state of Odisha nearly twenty-five hundred people were split into three arms, all receiving the malaria camps at different points. Tests were conducted at baseline and three follow-ups. The first group of villages received the malaria camps for the first time at the baseline visit and subsequently for the duration of the study. The second received the malaria camps for the first time after one year of routine malaria control strategies. The third group of villages was considered a control that had already received malaria camps before the study commenced. There was a statistically significant reduction in malaria parasite infection in study participants overall and for Arm A – the experimental group that received the intervention the longest. The researchers argue that this lower incidence – and the financial feasibility of the program – make malaria camps a promising tool for malaria control in remote areas of Odisha State – in pursuit of India’s goal of malaria elimination by 2030.
Source
The effectiveness of malaria camps as part of the malaria control program in Odisha, India
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
A new documentary tells a story of global scientific collaboration in the development of a new malaria vaccine, R21. Today, we take you behind the scenes with director and producer, Catherine Gale.
In this podcast, we ask:
- Why are malaria vaccines gaining so much attention now?
- What was the serendipidous origin of the documentary?
- What are the key moments of the documentary?
- What is the role of collaboration in scientific discovery?
With Catherine, Producer and Director at Wingspan Productions, and Bill Moss, a Deputy Director at the Johns Hopkins Malaria
About The Podcast The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
A new documentary from NOVA shines a light on the creation of R21, a new malaria vaccine.
Transcript
This month, a new documentary from NOVA shines a light on the creation of a new malaria vaccine. ‘The Battle to Beat Malaria’ tells the story of the development of R21 – from creation to WHO approval. Taking you behind the scenes in Oxford, UK, where the jab was developed as a PhD project, to the Serum Institute of India where millions of doses are prepared and stored. The documentary reveals the challenge of increasing the amount of protein that the vaccine creates, thereby the number of protective antibodies that the body creates. Of 142 vaccines developed, only a handful made it to clinical trials. And only two of those were approved for widespread use, R21 included. Through trial and error, the Oxford group eventually reached between 70 and 80% efficacy.
Source
The Batte to Beat Malaria (via PBS)
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
As COP28 emphasises the human cost of climate change, what will be the impact of rising temperatures and extreme weather events on malaria transmission?
In this podcast, we ask:
- How was health represented this year at COP?
- What is the impact of rising temperatures on malaria?
- How will extreme weather events, like flooding, affect malaria prevalence?
- Why is health resilience so important in mitigating climate-related disruption?
With Martin Edlund, CEO of Malaria No More and Courtney Murdock, Associate Professor at Cornell University
About The Podcast The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
The WHO launches its annual World Malaria Report at COP28, the UN's Climate Change Conference.
Transcript
The World Health Organization (WHO) has released its World Malaria Report for 2023 at the start of COP28, the UN’s Climate Change Conference. The headline figures are concerning. The WHO estimates that there were 249 million cases of malaria last year, resulting in 608000 deaths. These figures surpass pre-pandemic levels, with five countries bearing the brunt of this increase. This year, the report stressed the importance of climate change to malaria. Released at the start of COP, during its first-ever Health Day, it argues that extreme weather events, the frequency of which increase with global warming, could lead to unexpected outbreaks of malaria. In Pakistan, for example, there were an additional two million malaria cases as a result of flooding. Yet, looking beyond the raw numbers reveals a more nuanced reality. Malaria incidence – that’s the number of cases for every thousand people at risk – has fallen since the year 2000. But, despite averting over 2 billion cases globally, progress has stalled. Since 2015, malaria incidence has remained largely constant. We’re currently 55% off track of the WHO’s targets.
Source
WHO World Malaria Report 2023
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
An old malaria drug gets a new formulation. But how good is it – and will it drive resistance?
In this podcast, we ask:
- What are the limitations of current malaria vaccines?
- What is the concept of long-acting injectable (LAI) drugs?
- What are the clinical and chemical properties of atovaquone that make it suitable for this purpose?
With Theresa Shapiro, Professor, Johns Hopkins School of Medicine and Division Director, Division of Clinical Pharmacology.
About The Podcast The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
How ‘chemical vaccines’ could offer long-term protection against malaria in endemic areas, and combat the problems of dosing and drug resistance.
Transcript
Drugs used to prevent and treat malaria are vital tools in the malaria toolkit – but they aren’t perfect. When used to prevent malaria, people must remember to take them regularly, or they won’t be as effective. And when they’re used to treat the disease, the sheer scale of infection – with billions of parasites in the body – makes it likely that some of those parasites will be drug-resistant, leading to treatment failure. But, when you formulate the drugs differently, as nano-particles in a water-based solution, and inject them, like a vaccine, those same drugs can offer effective, long-lasting protection against the disease. This so-called ‘chemical vaccine’, based on the antimalarial drug atovaquone, has been shown in mice to effectively stop the infection and subsequently, the onward transmission of the parasites to mosquitoes. The long-term hope is that a single dose of the ‘chemical vaccine’ could offer long-term protection against malaria in endemic areas, and help combat the problems of dosing and drug resistance.
Source
Clinically relevant atovaquone-resistant human malaria parasites fail to transmit by mosquito
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Drug efficacy studies are revealing the spatial distribution of mutations causing artemisinin resistance - and it all starts with a drop of blood.
In this podcast, we ask:
- What is artemisinin resistance?
- What are some of the key molecular markers underpinning it?
- How can we overcome it?
With Didier Ménard, Director of the Institute of Parasitology and Tropical Diseases at the University of Strasbourg, and a visiting researcher at the Pasteur Institute.
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Researchers examine the rise of artemisinin drug resistance in Eritrea - and search for its genetic basis.
Transcript
Artemisinin – a key antimalarial drug – and other drugs derived from it, are fast losing their effectiveness across South East Asia and increasingly in Africa, too. To investigate this, researchers conducted a review of drug efficacy studies in the East African country of Eritrea. They looked for the rates of delayed parasite clearance in the three days following treatment – a key marker of partial drug resistance. They found a troubling pattern: delayed parasite clearance climbed from 0.4% in 2016 to 1.9% in 2017, followed by a marked increase to 4.2% in 2019. By isolating and sequencing parasitic DNA, they found that this trend was associated with the rise of a novel mutation to the Kelch13 region of the parasite, called R622I. Given the lack of alternative drugs, the emergence of resistance in Africa is concerning.
Source
Increasing Prevalence of Artemisinin-Resistant HRP2-Negative Malaria in Eritrea
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
In 1951, malaria was eliminated from the US. But just this past summer, the parasite that causes the disease has re-infected local mosquitoes and caused a handful of cases of malaria in three US states.
In this interview podcast, we ask:
- What should we make of these cases?
- Is the public possibly at risk of this once-eliminated disease?
- How can genomics help us to better understand what’s happened?
With Jane Carlton, Director of the Johns Hopkins Malaria Research Institute: https://publichealth.jhu.edu/malaria-research-institute
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Malaria returns to the US for the first time in decades. We share what we know so far.
Transcript
Today, another reminder that infectious diseases respect no borders. Malaria, a disease that was once endemic globally, has returned to the US for the first time in two decades. A number of cases have been confirmed in Florida, Texas and, most recently, one in Maryland. Crucially, in each of those cases, the people who got the disease hadn’t traveled to any malaria-endemic regions. The transmission was local. It’s thought that other people carrying the parasites from abroad infected mosquitoes in the US – and that those mosquitoes went on to infect other people. The infections have been P. vivax — a less deadly strain often found in South East Asia--and now P. falciparum — the most common and most deadly species — appearing in Maryland. The risk to the general public is low. But it’s unclear whether this is a random event — or a sign of things to come. Some experts hypothesize that possibly climate change and warming temperatures are making more places more suitable for malaria-carrying mosquitos to thrive.
Source
Maryland Department of Health announces positive case of locally acquired malaria [Maryland Department of Health]
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
In 2013, on the outskirts of Madrid, GSK was gearing up to test new medicines against malaria. But they had a problem.
In this month's podcast, we're joined by Janneth Rodrigues from GSK, Marcelo Jacobs-Lorena from Johns Hopkins University, and Etienne Bilgo from IRSS to share a story of collaboration that spans three continents, and which turned a headache into a success story.
Source
Delftia tsuruhatensis TC1 symbiont suppresses malaria transmission by anopheline mosquitoes
About The Podcast
The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
A naturally occurring bacterium renders the mosquito a poor transmitter of the malaria parasite.
Transcript
Scientists often grow mosquitos in the laboratory and infect them with malaria parasites to test new drugs and explore vector control. Unexpectedly, in a lab run by GSK in Spain, mosquitoes gradually lost the ability to sustain parasite development. To unwind this mystery, GSK turned to Marcelo Jacobs-Lorena, a researcher at Johns Hopkins University and sent him a bacterium they suspected was the blocking agent. The Hopkins team determined that these bacteria produce a substance called harmane – a strong poison to the malaria parasite without affecting the mosquito. Harmane kills the parasite in the mosquito either by ingestion or by contact--when the mosquito lands on a surface with harmane on it. Further experiments determined that this Delftia bacterium colonizes the mosquitoes for life where it suppresses survival of the parasite. Experiments conducted by researchers in Burkina Faso showed that this bacterium can efficiently colonize mosquitoes under conditions that simulate those of the field and that it inhibits locally circulating parasites. This bacterium promises to be developed into a new tool to combat malaria.
Source
Delftia tsuruhatensis TC1 symbiont suppresses malaria transmission by anopheline mosquitoes
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
After decades of research, the world’s first malaria vaccine is finally being rolled out in Africa. It’s a landmark in malaria success – but will it deliver a public health victory? In this podcast, we reveal the elusive target of the malaria vaccine and unpack the complex story of its development.
To locate blood vessels and establish infection, malaria parasites alternate between two states of movement in the skin – fast and slow. Interestingly, this shift in state might be guided by a cell found on the walls of capillaries.
Transcript
Of the dozens of malaria parasites the mosquito injects, only a handful will make it. To survive, the parasite needs to forage around for a blood vessel, enter it, and hitch a ride to the liver, where it can set up the infection. 3D imaging and statistical modelling reveals how this foraging plays out in the skin. After moving forward quickly, in a random and chaotic manner, the parasite sidles up to a blood vessel. Then, it changes tact. It moves slowly in a circular motion around the blood vessel, trying to find a way in. Interestingly, this shift in state might be guided by the parasite’s detection of a particular type of cell, called a pericyte. Pericytes are found on the walls of capillaries. Directly, or indirectly, they signal a point of entry, thereby luring the parasite in. Tracking parasites in the skin, therefore, reveals this novel finding: that pericytes play a role in the early stages of malaria infection.
Source
Plasmodium sporozoite search strategy to locate hotspots of blood vessel invasion
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Behavioral science is essential if the tools we develop in the lab are to generate impact in the field.
So, in this episode, we take a break from malaria biology to delve deep into human psychology of malaria control.
We explore the theory behind behavioral science and its implications for malaria control, and discuss a new tool from the Johns Hopkins Center for Communication Programs: the Malaria Behavior Survey.
With Doug Storey and Mike Toso of the Johns Hopkins Center for Communication Programs.
Bed nets are a staple tool in malaria control - but how do we make sure people actually use them? We discuss behavioral science, and the Malaria Behavior Survey from the Johns Hopkins Center for Communication Programs.
Transcript
Bed nets are a staple tool in malaria control. They’re reliable, effective, affordable and reusable. But how do we make sure people actually use them: sleep under one every night and store them properly when not in use? This is where behavioral science comes in – in particular the ‘Malaria Behaviour Survey’ from the Johns Hopkins Center for Communications Programs. It uses survey data to build an online dashboard that spells out the social, emotional and cognitive indicators that predict bed net use across sub-Saharan Africa. Whilst most surveys only measure individual behaviors related to malaria control, the ‘Malaria Behaviour Survey’ examines how what goes on in somebody’s head, heart and social network influences these behaviors. This wider context of individual decision-making helps malaria control programs tailor their messaging to more adequately meet the needs of their communities, and promote proper bed net use.
Source
Malaria Behavior Survey from the Johns Hopkins Center for Communication Programs
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Without funding, there can be no malaria fight. No bed nets distributed, no homes sparayed with insecticide and no scientific research to develop new tools.
For World Malaria Day 2023, we head to Washington D.C. to meet advocates in the U.S. who are passionate about rallying political support around the fight against malaria and raising the bar for the role young people play in global health advocacy.
Featuring Margaret Reilly McDonnell (United to Beat Malaria), Himaja Nagireddy (US Youth Observer to the UN), Joy Phumaphi (Executive Secretary, African Leaders Malaria Alliance), and David Walton (US Global Malaria Coordinator, PMI).
Malaria champions meet in Washington D.C. for the UN Foundation's 'United to Beat Malaria' Leadership Summit.
Transcript
In the centre of Washinton DC – just a five-minute walk from the White House – is a campaign at the forefront of malaria advocacy. The UN Foundation’s ‘United to Beat Malaria’ campaign connects Americans with the global movement to end malaria. Every year, it briefs advocates from across the country on the big challenges facing malaria. Drug and insecticide resistance. Limited funding. The need for resilient healthcare systems. Then, those advocates meet with Members of Congress. Last month, 90 advocates held over 140 meetings with congressional offices to make two important asks: Support a $2bn pledge for The Global Fund, an international resource which funds over 60% of malaria control programmes; and commit more than $820 million to The President’s Malaria Initiative, a US-led programme working with over 25 endemic countries. These advocates, known as ‘champions’ are diverse and committed. We meet them next time in the Extended episode of the Johns Hopkins Malaria Minute.
Source
United to Beat Malaria Champions Return to Washington DC for Annual Leadership Summit
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
An invasive mosquito species, Anopheles stephensi, is threatening to redefine malaria in Africa.
In this episode, we speak to Eric Ochomo from the Kenya Medical Research Institute, and Seth Irish from the World Health Organization, about the rise of the Anopheles stephensi in Africa. We discuss why the mosquito is in Africa, what this means for malaria, and—more importantly—what can be done.
The migration of Anopheles stephensi, an invasive mosquito species, threatens to redefine malaria in Africa.
Transcript
Malaria in Africa is mainly rural, and peaks during the rainy season. The primary culprit is Africa’s main malaria vector: Anopheles gambiae. But another malaria vector – called Anopheles stephensi – is making its way into the continent from SE Asia. Anopheles stephensi can transmit malaria in both rural and urban settings, and breed in small volumes of water. Because it’s not dependent on rainfall, it can transmit the disease year-round. It can even transmit Plasmodium vivax malaria – a form of the disease that can relapse. In one study in Kenya last year, 16 out of the 55 mosquitoes captured were Anopheles stephensi. Almost a third. So just how much of a threat is Anopheles stephensi – and what can be done? Listen next time on Malaria Minute Extended.
Source
Anopheles stephensi in Kenya: potentially substantial threat to malaria transmission in urban and rural areas (Evidence Brief from Kenya Medical Research Institute)
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
The malaria parasite is becoming increasingly resistant to the drugs we use against it.
Caroline Simmons, a geneticist at the University of South Florida, is trying to understand what's driving this. By creating mutants of the parasite, and testing drugs against them, she's piecing together the complex puzzle of antimalarial drug resistance.
Drug resistance is on the rise, but genetics can help us understand what's driving it. Here, researchers identify a protein associated with resistance to artemisinin, a key malaria drug.
Transcript
Artemisinin-based combination therapies (ACT) are considered the most effective method to treat malaria. Yet drug resistance to them is on the rise, spreading from Southeast Asia to Africa, becoming a real problem. A genetic approach to drug resistance can help us understand the genes responsible for this. Artemisinin resistance has long been associated with mutations to a protein called Kelch13. By screening the parasite genome, researchers have identified another protein associated with resistance to the drug. Called KIC5, this protein helps maintain nuclear homeostasis – balance within the parasite’s cell – as it lives in human red blood cells. When expressed, it helps the parasite overcome artemisinin stress by supporting DNA repair and other mitochondrial activity. But when it’s disrupted, the parasite can’t deal with this stress and becomes sensitized to the drug. Almost like flipping a switch, disrupting KIC5 makes artemisinin work again.
Source
Protein KIC5 is a novel regulator of artemisinin stress response in the malaria parasite Plasmodium falciparum
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
When Clive Shiff completed his entomology training, he was told that malaria was on its way out.
But as we know, the disease persisted, continuing to claim lives and livelihoods.
In January's Malaria Minute Extended, we speak with Clive Shiff, Professor Emeritus at Johns Hopkins University, on the rise of the bed net and the importance of African leadership in the push for malaria eradication.
How can we account for malaria cases during the dry season, when mosquitoes are typically dormant? It turns out that trees might be the root of the problem...
Transcript
Malaria is often thought of as a seasonal disease. Transmission peaks during the rainy season – when standing water creates the ideal conditions for mosquitoes to thrive – and falls in the dry season when mosquitoes become dormant. But in those dryer months, the disease doesn’t go away completely. In some areas, mosquitoes remain active, continuing to bite and transmit malaria to humans. So how can we account for those cases? It turns out trees might be the root of the problem… Humidity created by water evaporating from tree leaves might be creating ideal microclimates for malaria to thrive. To investigate, researchers placed mini-loggers onto trees and granaries near where people sleep in nine study sites across Southern Zambia. Humidity and temperature in these areas was associated with local health centre-reported incidence of malaria.
Source
Impact of aerial humidity on seasonal malaria: an ecological study in Zambia
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
The malaria parasite has a lot of genes: over 5,000.
But how does it know when to express certain genes versus others? And what purpose do these different genes serve in malaria virulence and transmission?
We dive deep into the nucleus of the cell with Catherine Merrick of the University of Cambridge to find out. She reveals the role of epigenetics in malaria transmission and the discovery of a new epigenetic mechanism that might help us gain the upper hand on malaria.
A newly-discovered epigenetic marker may reveal how the parasite survives in the human host
Transcript
The malaria parasite is resilient, with thousands of genes that can be differentially expressed to evade the immune system. The expression of those genes is determined by environmental factors and controlled through ‘epigenetic markers’. They turn the genes on or off – and give the parasite flexibility in the human host. A new marker has recently been discovered in Plasmodium falciparum. It’s called histone lactylation and may help the parasite survive, through its response to inflammation. As the parasite respires in the blood, it produces lactate. A build-up of lactate – hyperlactatemia – can cause an inflammatory response. But that inflammatory response can be so strong that it could kill the parasite that caused it. It’s thought that, through histone lactylation, the parasite turns on genes that make it more resistant to inflammation.
Source
Histone lactylation: a new epigenetic axis for host–parasite signalling in malaria?
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
In 2010, the NIH launched the ICEMRs, a global network of research centers focused on eliminating malaria. They track malaria over time - across the globe - to help inform government policy with the mission to move the needle toward a malaria-free world.
Malaria is a spectacularly complex disease, and this mission is challenging. Here, we zoom in on the Southern and Central Africa ICEMR to learn more. With Principal Investigator William Moss, Deputy Director of the Johns Hopkins Malaria Research Institute.
A special supplement in the American Journal of Tropical Medicine and Hygiene marks the global impact of the International Centers of Excellence for Malaria Research.
Transcript
Open the most recent edition of the American Journal of Tropical Medicine and Hygiene, and you’ll find a Special Supplement. A series of papers to highlight the global impact of the ICEMRs, the International Centers of Excellence for Malaria Research. Funded by the NIH, the research network spans the globe – in 17 malaria-endemic countries across South East Asia, Africa and South America. The ICEMRs provide knowledge, tools, and evidence-based strategies in a variety of settings. Importantly, each ICEMR develops a close relationship with their field sites, allowing investigators to study malaria in depth and over an extended period of time. The scientific knowledge generated from this close relationship is key to informing policy, and next time, in Malaria Minute Extended, we take a closer look at how ICEMRs work on the ground in Southern Central Africa with Principal Investigator, William Moss.
Source
International Centers of Excellence for Malaria Research: Achievements of the Collaborative Network during the Past Decade
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Bed nets and insecticides are often used to combat malaria.
But how do we know that those tools work?
Trials can indicate the effectiveness of these tools in a specific time and place - but what about in the real world?
With Jane Frances Namuganga, Project Coordinator, Infectious Diseases Research Collaboration (IDRC), Uganda.
The use of bed nets and spraying indoor insecticides are key vector control measures in the fight against malaria - but they won't last forever.
Transcript
The use of bed nets and spraying indoor insecticides are key vector control measures in the fight against malaria. Many malaria-endemic countries, like Uganda, have government schemes to recurringly roll out these interventions.
The use of those tools results in a dramatic reduction in malaria transmission: up to 84% fewer cases. But over time, as those tools are rolled out again and again, the impact goes down, ultimately leading to a resurgence.
In five regions of North Eastern Uganda, although bed nets and indoor residual spraying were initially effective, seven years after they started to be rolled out, cases went up by 39% compared to the pre-programme baseline.
This highlights the importance of surveillance of malaria on the ground. But also the age-old fact that one tool for malaria is never enough. The toolbox always needs to be updated.
Source
Resurgence of malaria in Uganda despite sustained indoor residual spraying and repeated long lasting insecticidal net distributions
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
When you give a vaccine, you generate a team of antibodies. Some will be effective, others not so much.
Suppose you took the very best player and transformed your immune system into a team of all-stars?
Would you increase your chances of winning the game?
With Robert Seder, Principal Investigator at NIAID, NIH.
Monoclonal antibodies are a relatively new tool in the fight against malaria, hoped to offer prolonged protection against disease. We take a look at the results of a new clinical trial investigating L9LS, a next-generation antibody for malaria.
Transcript
Monoclonal antibodies are a relatively new tool in the fight against malaria. Scientists recently put a next-generation antibody called L9LS to the test in a small, Phase 1 clinical trial.
17 American malaria-naive adults were injected intravenously at either 1, 5, or 20 milligrams per kilogram of body weight or subcutaneously at 5 milligrams per kilogram of body weight. They were then infected with malaria by mosquito bite.
All participants in the control group got malaria. Only 2 out of the 17 participants protected by the monoclonal antibody, L9LS, got malaria.
This small-scale study shows that L9LS is safe and effective in a controlled setting and mediates protection at low doses by subcutaneous route; larger field studies are needed to answer dosage and practical questions.
Source
Low-Dose Subcutaneous or Intravenous Monoclonal Antibody to Prevent Malaria
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
James Watson is a statistician working to improve the diagnosis and treatment of severe malaria. He's found that many children in African settings are probably getting misdiagnosed.
As many as one-third of children may be getting misdiagnosed with severe malaria when in fact their symptoms are being caused by something else.
Transcript
With coma and severe anaemia, the symptoms of severe malaria can be punishing. But how do you ensure that those symptoms are because of malaria, and not something else?
As many as one-third of children diagnosed with severe malaria in high-transmission settings in Africa could in fact be sick of another cause. That’s according to new research.
Many patients can have malaria, but it is asymptomatic malaria. Their severe symptoms - similar to malaria symptoms - could be caused by something else.
To diagnose malaria, a blood smear is done to look for the malaria parasite, or by looking for a protein - a byproduct of the parasite - in the blood which indicates - indirectly - recent malarial activity.
Researchers compared the diagnosis of severe malaria against two markers of malaria infection: platelet count and concentrations of this parasite protein. They found that these markers together are a good way to diagnose severe malaria and demonstrate that some children may be getting misdiagnosed.
Source
Improving the diagnosis of severe malaria in African children using platelet counts and plasma PfHRP2 concentrations
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Marcelo Jacobs-Lorena and Joel Vega-Rodriguez unlock part of the mystery of how the malaria parasite moves in the mosquito.
We explore the long history of this story - and it involves glow-in-the-dark mosquitoes.
Researchers at Johns Hopkins and NIH genetically engineered malaria-carrying mosquitoes to block malaria infection in the human skin.
Transcript
Without mosquitoes, malaria can't be transmitted. To establish infection, the malaria parasite must move in the human skin to find a blood vessel.
It’s able to move by activating a human protein called plasminogen which is converted into a potent enzyme called plasmin. This breaks down the skin protein network, allowing the parasite to move.
But one protein called PAI-1 stops this conversion.
Now, researchers at Johns Hopkins and the NIH have genetically engineered mosquitoes to produce PAI-1. The mosquito delivers the parasite with saliva. If the salvia contains the PAI-1 inhibitor, the parasite can’t move and find a blood vessel.
In addition, the protein also blocks a different stage of parasite development in the mosquito gut.
Engineering mosquitoes to produce PAI-1 could block malaria transmission.
Source
Transgenic Anopheles mosquitoes expressing human PAI-1 impair malaria transmissionCollective migration reveals mechanical flexibility of malaria parasites
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
The malaria parasite up close, brought to life by cell biology and physics.
Freddy Frischknecht and Ulrich Schwarz describe the vortices-like movement of sporozoites and the benefits of interdisciplinary research.
Researchers look under the microscope to better understand how sporozoites move in the skin.
Transcript
The malaria parasite changes shape throughout its lifecycle, and it’s the sporozoite - a slender, crescent-like form of the parasite - which is injected into the human by mosquitoes.
Accumulating in the mosquito in the salivary glands, sporozoites are injected individually into the skin, through the mosquito’s proboscis. In the skin, sporozites migrate to find and enter a blood vessel.
Researchers wanted to better understand how sporozoites move in the skin. Rather than looking at single sporozoites, they turned to the cell collectives originating from the salivary glands.
In dissected salivary glands, sporozoites move in vortices, spinning circles with a hole in the middle. While the holes demonstrate that sporozoites are relatively stiff and cannot bend too much, in the rest of the vortices they observed strong mechanical flexibility. Moreover, the vortices as a whole oscillated in size.
Source
Collective migration reveals mechanical flexibility of malaria parasites
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Matt Ippolito is an Assistant Professor of Medicine at Johns Hopkins Medicine, using evidence on the ground to answer important research questions.
He reveals how science is an evolving process with different stakeholders - and one where not everything is as it might first appear.
Patients with low platelet count might benefit most from whole blood transfusion for severe malaria anaemia; should be prioritised in clinical management of the disease. Transcript
The clinical presentations of malaria can be severe, particularly severe malaria anaemia: a condition of the blood which reduces the amount of hemoglobin in the body or oxygen delivered to the vital organs.
Whole blood transfusion is often used to treat it – but does it work?
In a review of clinical records in Zambia, whole blood transfusion reduced the odds of death among patients with anaemia by 35%. That’s one life saved for every 14 transfusions.
But it was most effective among anemic patients with another condition: thrombocytopenia, or low platelet count. Here, one life was saved for every 5 transfusions.
More research is needed. Yet patients with low platelet count benefit most from blood transfusions and should be prioritised in clinical management of the disease.
Source
Whole blood transfusion for severe malarial anemia in a high Plasmodium falciparum transmission setting
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Janet Hemingway is the President of the Royal Society of Hygiene and Tropical Medicine, bringing together stakeholders to overcome insecticide resistance. She doesn’t shy away from big logistical challenges and wants the world to know that insecticide resistance is a threat.
PBO nets prove 25% more effective than pyrethroid-only nets in national trials in Uganda.
Transcript
Mosquito nets imbued with insecticide are key to controlling malaria. So much so, that the mass distribution of bed nets with pyrethroids has led to a dramatic fall in malaria transmission. But this widespread use has also led to widespread resistance. Nets with PBO, piperonyl butoxide, might be the answer. PBO blocks out the mosquito’s resistance mechanism so pyrethroid can work again. In recent testing on a national scale in Uganda, pyrethroid nets with PBO proved more effective, in areas of high and low malaria transmission - with different levels of pyrethroid resistance. The scale of the trial was massive; like having lots of different trials in one. The nets were about 25% better at reducing malaria transmission than nets with pyrethroid alone. Today PBO nets are now the dominant net type distributed in Africa.
Source
LLIN Evaluation in Uganda Project (LLINEUP) – Impact of long-lasting insecticidal nets with, and without, piperonyl butoxide on malaria indicators in Uganda: study protocol for a cluster-randomised trial
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Abdoulaye Diabate is leading the research on genetic technologies for malaria control in Burkina Faso, the only country in Africa to be working with genetically modified mosquitoes. He hopes to bring gene drive, an innovative genetic tool which could help reduce malaria transmission, to Africa in the future.
Target Malaria report on the first-ever release of genetically modified mosquitoes in Africa. Transcript Genetically engineered so they can’t transmit malaria, gene drive mosquitoes could be game-changing. But we first need to understand how genetically modified mosquitoes reared in a lab behave in the wild. And in 2019, Target Malaria released on a small scale, and for the first time in Africa, genetically modified sterile male mosquitoes. Now, these weren’t gene drive mosquitoes – ones with special genetic traits to be inherited. These mosquitoes couldn’t mate - so when they died, so did any genetic modification. But this study does demonstrate that GM mosquitoes are as mobile as wild mosquitoes, and they swarm normally. But GM mosquitoes did have a fitness cost, dispersing less efficiently with a shorter life span. This important piece of research forms part of the phased development of gene drives, which Target Malaria hope will one day be brought to Africa.
Source
Mark-release-recapture experiment in Burkina Faso demonstrates reduced fitness and dispersal of genetically-modified sterile malaria mosquitoes
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Angela Minassian reflects on what the malaria community can learn from the ‘supercharged’ COVID vaccine effort. Angela Minassian, MD, is the Chief Investigator and clinical lead on the blood-stage and transmission blocking malaria vaccine programs at the University of Oxford.
A new blood-stage malaria infection model helps solve a problem hindering research. Transcript The world urgently needs new drugs and vaccines to eradicate malaria. Whilst there’s good headway against P. falciparum - the deadliest form of the parasite –research into P. vivax - the second deadliest – lags behind. Why? Researchers lack stable cultures of the parasite needed to infect people to test the efficacy of drugs and vaccines. We need a way of doing this reliably and an international team of researchers has come up with a way: the blood-stage malaria infection model. They first collected blood samples of a P. vivax strain in Thailand, fed the samples to mosquitoes and transported these mosquitoes to the UK, where they were used to infect two adults. Those volunteers then had their blood collected before being treated, and this blood was used to infect another six adults. This new blood-stage malaria infection model will help to test drug and vaccines more easily in the future.
Source
Controlled human malaria infection with a clone of Plasmodium vivax with high quality genome assembly
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
George Dimopoulos tells his story of how he evolved into a Mosquito Explorer. Listen in to learn how one scientist navigated his scientific journey.
The 'population replacement' strategy for mosquitoes to disrupt malaria transmission. Transcript
Genetic tools to control the malaria mosquito are becoming increasingly attractive, particularly transgenesis: the process of introducing genes into the mosquito to stop it from transmitting malaria. Mosquito transgenesis can either suppress a mosquito population entirely or replace it with a strain that can’t transmit malaria to humans. And it’s this ‘population replacement strategy’ is the primary focus of a new article in the Trends in Parasitology journal. It details how population replacement can be achieved by improving the mosquito’s ability to attack the parasite, or by inactivating the genes the parasite uses to infect the mosquito. It also outlines the methods of introducing these genes to the mosquito - on a molecular and population level. Yet, the article also highlights the technical and public challenges with transgenesis, particularly regulation and community engagement in releasing mosquitoes.
Source
Mosquito transgenesis for malaria control
Research on the Wolbachia bacteria is applied to the malaria-transmitting Anopheles mosquito, with exciting implications for vector control. Transcript
New tools are needed to control the Anopheles mosquito, the vector of malaria. Bacteria called Wolbachia might be the answer. Although Aedes mosquitoes do not naturally carry Wolbachia, when the bacteria were introduced from other sources, they could no longer transmit pathogenic viruses, like dengue. Harnessing this technology to control vector populations is now being applied to the malaria-transmitting Anopheles mosquito. New research has shown that ‘cytoplasmic incompatibility’ [CI] can be induced in Anopheles by expressing the Wolbachia cifB gene in male mosquitoes, and that this lethality can be reversed by expression of the cifA gene. In other words, when male mosquitoes mate with females that do not carry the bacteria, they cannot produce offspring. Knowing this will help pave the way for the use of Wolbachia to control malaria mosquitoes in the field.
Source
Wolbachia cifB induces cytoplasmic incompatibility in the malaria mosquito vector
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and share with the global community.
Malaria cases rose in 2020, as did death from the disease--by 12%. What caused this? Transcript
This week, the WHO published its annual World Malaria Report, and the headline figures are stark. There were an estimated 241 million cases of malaria in 2020, up 14 million from the year before. 627,000 of these cases resulted in death, up 12% from the year before. This uptick in death is attributed largely to COVID, with less access to controls and prevention, like bed nets, indoor residual spraying and preventative drug treatment. In the early stages of the pandemic, the WHO warned of a ‘worst case scenario’ for malaria in which deaths could double due to service disruption. Yet, the collaborative effort of countries and partners averted this situation and minimised the disruption. Since 2000, global efforts have reduced malaria death rates by half and saved 10.6 million lives.
Source
World malaria report 2021
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and share with the global community.
Single-genome sequencing reveals evolution of P vivax malaria parasites within the human host and identifies mutations that could confer drug resistance and escape from natural or vaccine immune responses. Transcript
The fight against malaria is often described as a game of catch up, as the malaria parasite adapts and evolves to resist drug treatment and, in some cases, even diagnosis. Understanding the parasite on a molecular level, therefore, is becoming increasingly important, and one the ways of doing this is to look at the parasite’s DNA. DNA sequencing is a tool that reveals the order of bases - the chemical building blocks of life - in a particular segment of DNA. When applied to the single cells of P. vivax parasites, new insights were uncovered. Recurrence of symptoms in patients with low parasitemia malaria infections and not treated with primaquine, even after many months, was due to relapse rather than reinfection. The researchers also identified several mutations which could confer drug resistance and escape from natural or vaccine immune responses.
Source
Single-genome sequencing reveals within-host evolution of human malaria parasites
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Every year, the Johns Hopkins Malaria Research Institute hosts its Future of Malaria Research Symposium. It highlights the work of younger scientists, giving them the chance to 'run the show'. This podcast is a conversation between this year's keynote speaker, Etienne Bilgo, and director of the Malaria Research Institute, Peter Agre. Listen to hear their reflections on where we are in the fight against malaria, and what to expect from the symposium this Friday, November 12th.
Large cage experiments that emulate the real-world environment demonstrate the viability of gene drive technology. Transcript
Gene drives have the potential to reduce malaria transmission by controlling mosquito reproduction. By targeting the doublesex gene of Anopheles mosquitoes, they can render female mosquitoes infertile and crash the entire population over time. But, for the most part, gene drive studies so far have been conducted in small laboratory cages, which aren’t representative of wild populations with complex feeding and reproductive behaviours. A new experiment changes this, however, by testing the technology in larger cages which emulates the real-world environment. Here, the gene drive spread rapidly through the experimental groups, resulting in complete population suppression within a year, demonstrating the viability of the technology. More broadly, this large cage approach offers a bridge between the lab and the field, getting the best of both experimental control and real-world population dynamics before being tested in nature, which is in the works to be done in the foreseeable future.
Sources
Gene-drive suppression of mosquito populations in large cages as a bridge between lab and field
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
New research into the role and function of the apicoplast, a plant-like structure within the malaria parasite, has changed scientists’ perceptions of how the parasite survives. Transcript
The apicoplast, a plant-like structure within Plasmodium falciparum malaria parasites, has long been thought to have one essential function in blood-stage parasites: to produce isoprenoids, chemical building blocks essential for parasite survival. But it’s now been found that the apicoplast also produces a metabolite called Co-A, and that this product is also required for parasite survival. Interestingly, when the apicoplast is targeted by existing antimalarial drugs, it fragments into vesicles, but these remnant vesicles still produce Co-A. So, when you disrupt the apicoplast, you don’t inactivate all of its metabolic pathways, as was previously believed. This new insight into the complexity of the apicoplast – and its enduring activity even when disrupted - has changed scientists’ perception of the organelle and could inform new drug development strategies.
Sources
Dephospho-CoA kinase, a nuclear-encoded apicoplast protein, remains active and essential after Plasmodium falciparum apicoplast disruption
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
Results from a large study in Ethiopia showed that P. falciparum malaria parasites have mutated and have the worrisome ability to avoid being detected by the widely utilized RDTs. Transcript
Controlling malaria requires an effective ‘test and treat’ strategy. Traditionally, the most utilized test in Africa is the rapid diagnostic test (RDT), which detects histidine-rich protein 2, a protein made by P. falciparum malaria parasites. Although histidine-rich protein is abundant in human blood during malaria infection and an excellent target for testing - it’s been reported since 2010 that mutations in the parasite have resulted in the deletion of the gene encoding this protein, enabling those parasites to avoid detection by RDTs.In a large study of nearly 13,000 participants conducted in Ethiopia results from RDTs were cross-referenced with those from more reliable methods of diagnosis. Researchers found that RDTs would miss an estimated 9.7% of cases owing to the deletion of this protein, significantly higher than the WHO’s 5% threshold for test regime change.
Source
Plasmodium falciparum is evolving to escape malaria rapid diagnostic tests in Ethiopia
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
The world’s first-ever malaria vaccine is recommended for widespread use among children by the WHO. Transcript
The world’s first-ever malaria vaccine has this week been recommended for widespread use among children by the WHO. Thirty years in the making, RTS,S offers around 40% protection from P. falciparum malaria, and around 30% protection from the severe form of the disease. Though not a ‘magic bullet’, the use of the vaccine in sub-Saharan Africa and other regions with moderate-to-high malaria transmission could see tens of thousands of lives saved each year. The vaccine is safe, well-tolerated and highly cost-effective. Reacting to what amounts to a major policy announcement is Peter Agre, Director of the Johns Hopkins Malaria Research Institute:
“It is a momentous day for science. This first malaria vaccine, thirty years in the making, was created by the collective and persistent effort of many people globally. The vaccine will not put an end to all deaths, yet it is a major advance that will save lives, save children.”
Source
WHO recommends groundbreaking malaria vaccine for children at risk
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
A new trial investigates whether drugs or vaccines – or a combination of both – are most effective at preventing malaria during the seasonal period, and the WHO’s malaria director considers the current situation in malaria eradication. Transcript
The return of mosquitos during the rainy season results in particularly high malaria transmission. During this ‘seasonal period’, drugs are often given to prevent the disease through what’s known as seasonal malaria chemoprevention, or SMC. Yet, despite these interventions, transmission often remains high. In a three-year trial of nearly 7,000 children, the RTS,S vaccines were shown to be as good as SMC in preventing malaria during the seasonal period. But when the two interventions were combined, the number of malaria events fell substantially - to almost a third of the single intervention groups. RTS,S could, therefore, be used as a seasonal vaccine, with an annual booster just before peak transmission. And the WHO’s malaria chief, Dr Pedro Alonso, has highlighted the potential of vaccines and new technology to solve the malaria problem, but reinforced the need for universal access to healthcare and better use of data.
Source
Seasonal Malaria Vaccination with or without Seasonal Malaria Chemoprevention
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.
We're used to thinking of vaccines for individual protection. But what about a malaria jab to protect the mosquito? Transcript
Finding antigens for a transmission-blocking vaccine to target is a tough job - only two have reached clinical trials. Though given to humans, these vaccines aim to disrupt the malaria lifecycle in the mosquito, and scientists have now found that Pf77 and male development gene 1 (PfMDV-1) could be potential candidates. In the lab, mice immunised with these antigens successfully developed antibodies against them. Researchers then isolated these antibodies from the mice and fed them to mosquitoes - along with malaria parasites - to test if they can inhibit parasite development. Indeed, they reduced the number of oocysts - the form of the parasite containing transmissible sporozoites - by up to 93%. And when researchers looked in Ghanaian adults naturally exposed to malaria, they found antibodies to these proteins, suggesting natural exposure could boost responses elicited by vaccination.
Source
Plasmodium falciparum Pf77 and male development gene 1 as vaccine antigens that induce potent transmission-reducing antibodies
About The Podcast
The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and share with the global community.