Photo by STR/NurPhoto via Getty Images Although several rapid diagnostic tests are already available in South Africa, they are not consistently reliable, says the National Health Laboratory Service. Inaccurate test results could lead people to believe they do not have the coronavirus, so they do not self-isolate and then inadvertently infect others, it warned. The NHLS needs 300 volunteers for a Covid-19 rapid test study to check if tests brought into the country work. The National Health Laboratory Service needs 300 volunteers for a Covid-19 rapid test study, because several rapid diagnostic tests that are already available in South Africa are not consistently reliable, the pathology body has said.