Limited COVID-19 testing? Researchers in Rwanda have an idea

KIGALI, Rwanda (AP) — Like many countries, Rwanda is finding it impossible to test each of its citizens for the coronavirus amid shortages of supplies. But researchers there have created an approach that’s drawing attention beyond the African continent.

They are using an algorithm to refine the process of pooled testing, which tests batches of samples from groups of people and then tests each person individually only if a certain batch comes back positive for COVID-19. Pooled testing conserves scarce testing materials.

Rwanda’s mathematical approach, the researchers say, makes that process more efficient. That’s an advantage for developing countries with limited resources, where some people must wait several days for results. Longer waits mean a greater chance of unknowingly spreading the virus.

Those behind the algorithm have expressed some pride that a potential solution to a dogged problem in the global crisis is coming from Africa. Experts have noticed. Sema Sgaier, a Harvard assistant professor of global health, called the Rwanda approach an example of the “incredible solutions in very resource-poor settings” that have come out of the continent.

Some experts, and even the researchers, have noted concerns that the complexity of the approach could deter its widespread use. “If you told this to a technician, they would say, ‘What a mess. I want a simple scheme,'” Sigrun Smola, a molecular virologist at Saarland University Medical Center in Germany, told the journal Nature in a recent article on Rwanda's and other approaches to pooled testing.

The method developed by Wilfred Ndifon, a mathematical epidemiologist and director of research at the African Institute for Mathematical Sciences Global Network in Rwanda’s capital, Kigali, is now being turned into software that will guide lab technicians,...