Implementation of rapid tests could be a game changer for Africa

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

Throughout the pandemic, African nations were recommended to use polymerase chain reaction, or PCR tests, to identify COVID-19 cases because they are considered the most accurate. However, countries have found it difficult to perform tests on a widespread basis, because PCR testing requires laboratories, reagents, and trained experts to perform them. This has led to a concentration of testing capacity mainly in capitals and large cities.

But following the recent WHO 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 Thursday.

A cheaper and faster test

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

But testing rates are, on average, even lower in Africa than in many other regions, he said. For example, while Senegal has significantly increased its testing capacity, it has still 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, national authorities are believed to be losing a significant number of COVID-19 cases, crippling their ability to quickly respond to outbreaks within their borders.

While PCR testing is considered the gold standard, African countries have faced challenges in accessing adequate amounts of reagents, due to global competition and because they are expensive, said Dr. Susan Ndidde Nabadda, director of the Uganda National Health Laboratory and Central Public Health Services. Laboratory, during the press conference.

There is also a need for laboratory infrastructure, highly trained personnel, and the transfer of samples to laboratories. 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 who they test, rather than implementing widespread testing campaigns to better understand how the pandemic is unfolding in their countries, Moeti said. This has been one of the most difficult aspects of the response on the continent, he added.

Until now, rapid diagnostics have not been widely used because their efficacy was in doubt. But in late September, the 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 less than 30 minutes, Moeti said. They should allow countries to decentralize testing outside of urban areas.

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

A phased approach

Globally, Access to COVID-19 Tools Accelerator, a coalition launched by the WHO and its 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 countries.

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

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

The WHO recommends the use of these tests in outbreaks where there is no access to the PCR test, including in crowded settings such as prisons, among high-risk groups, including healthcare workers, and in places where there are high levels of community transmission. .

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