Workers affiliated to labour union Nehawu are continuing their strike action at the National Health Laboratory Service. The Union says wage negotiations reached a deadlock over a pay increase and other issues. The Laboratory Service provides diagnostic pathology services to government, such as blood tests. Acting CEO at the National Health Laboratories Services in Johannesburg Professor Shabir Madhi says they have put contingency measures in place which have, largely, been working, but adds that there have been some challenges.