Roll out of rapid testing could be a 'game changer' for Africa

NAIROBI — African nations are planning to ramp up the use of rapid diagnostic tests as part of their national strategies for testing for COVID-19, according to Dr. Matshidiso Moeti, World Health Organization regional director for Africa.

Throughout the pandemic, African nations were advised to use polymerase chain reaction, or PCR tests, to identify COVID-19 cases because they are considered the most accurate. Countries have had challenges in testing widely, however, because PCR tests require laboratories, reagents, and trained experts to conduct them. This has led to a concentration of testing capacity mainly in the capitals and large cities.

But following WHO’s recent approval of rapid diagnostic tests for use in surveillance, countries can now start using them to expand the number of people they test, in addition to PCR testing.

This could be a “game changer” in the fight against COVID-19 across the continent, Moeti said during a press conference on Thursday.

A cheaper, quicker test

African nations have conducted over 17.5 million tests since the beginning of the pandemic, according to the Africa Centres for Disease Control and Prevention. Initially there were only two labs that could test for COVID-19 on the continent. Now there are about 750, Moeti said.

But the rates of testing are, on average, still lower in Africa than in many other regions, she said. For example, while Senegal has significantly increased its testing capacity, it still has tested 14 times fewer people than the Netherlands, and Nigeria has tested 11 times fewer people than Brazil. These countries were compared because they have similar population sizes.

Because of this, it’s believed that national authorities are missing a significant number of COVID-19 cases — crippling their ability to quickly respond to outbreaks within their borders.

While PCR tests are considered the gold standard, African countries have faced challenges in accessing adequate quantities of reagents, because of global competition and because they are expensive, said Dr. Susan Ndidde Nabadda, head of the Ugandan National Health Laboratory Services and Central Public Health Laboratory, during the press briefing.

There is also a need for lab infrastructure, highly trained staff and the transfer of samples to labs. PCR tests typically take several days to return results.

Because of these challenges, there has been a tendency for African countries to prioritize and ration whom they test, rather than rolling out widespread testing campaigns in order to better understand how the pandemic is playing out in their countries, Moeti said. This has been one of the most difficult aspects of the response on the continent, she added.

Until now, rapid diagnostics have not been widely used because their efficacy was in question. But at the end of September, WHO approved for emergency use what it has determined to be two high quality, antigen-based rapid diagnostic tests, produced by SD Biosensor Inc and Abbott.

The new rapid tests are easier to use, cheaper, and provide results in under 30 minutes, Moeti said. They should enable countries to decentralize testing away from urban areas.

“This will help us isolate the patients immediately, break the transmission and reduce exposure to the health workers because they will have timely and quick diagnosis of the patient,” Ndidde Nabadda added.

A phased approach

Globally, the Access to COVID-19 Tools Accelerator, a coalition launched by WHO and partners, is making 120 million of these tests available to low- and middle-income countries. UNITAID, the Global Fund to Fight AIDS, Tuberculosis and Malaria, FIND, and Africa CDC will initially distribute these tests in 20 African nations.

In Uganda, for example, the tests will be introduced in a phased approach, through a pilot program, as the country generates data on how they perform. Initially, health workers will cross-check positive tests with PCR tests to confirm the accuracy of the results, Ndidde Nabadda said.

The tests are especially effective when someone has symptoms and a high viral load, but they are not necessarily the best tool to catch the infection as early as possible, Ndidde Nabadda said. Because of this, they are not a substitute for PCR tests.

WHO recommends the use of these tests in outbreaks where there isn’t access to PCR testing, including in crowded settings like prisons, among high risk groups, including health workers, and in places where there are high levels of community transmission.

WHO is not recommending these tests at border crossings as a tool to confirm that someone is free of COVID-19 and the agency will continue to analyze their performance, Moeti said.