Public Health Leaders Boost Testing to Forestall Future COVID-19 Waves

ADF STAFF

Since the onset of the global pandemic, African nations have conducted 72 million tests for COVID-19. In the eyes of public health experts, that’s not nearly enough to prevent another wave of infections from sweeping the continent.

As the current wave of infections — the third for most countries, the fourth for some — begins to recede, the Africa Centres for Disease Control and Prevention and the World Health Organization’s (WHO’s) Africa regional office plan to ramp up testing across the continent. By expanding disease surveillance, public health leaders hope to identify a potential new wave and stop it before it can gain momentum.

“The centrality of good public health is surveillance,” Africa CDC Director Dr. John Nkengasong said during a recent briefing. “We really need to bring surveillance back to bear as an important tool to fight this pandemic.”

In the months since the delta variant flooded the continent, researchers have identified the eta and C.1.2 variants as having the potential to create another wave of infections.

So far, both have been overwhelmed by the more transmissible delta variant, but they are spreading. The eta variant is found across multiple West African countries. C.1.2 is concentrated in Southern Africa.

It’s unclear if either variant is more transmissible or deadlier than its predecessors.

“We have to keep in mind that this is very early data,” said Dr. Alan Christoffels, director of the South African National Bioinformatics Institute.

With the spread of COVID-19 continuing, the watch for new variants in the population needs to be a continuous activity, Nkengasong said. Testing needs to move beyond travelers and people showing symptoms to include those who are asymptomatic, he added.

“It will be a challenge,” he said. “But we are in a tough situation. We have to use everything.”

Disrupting a future COVID-19 wave means more testing, followed by isolation for those who test positive. Nkengasong said the plan is to dispatch antigen-based rapid tests for widespread assessments. The tests are portable and simple to use, making them a key part of surveillance in rural areas, he said.

Antigen-based tests, which detect markers of the COVID-19 virus, generally return a result in about 15 minutes. But they’re also less accurate than the lab-based PCR tests, which read the virus’s genetic code. PCR tests, however, can take days to return results, making them less useful for the kind of mass surveillance public health officials want to conduct.

To help expand surveillance, the WHO Africa regional office is investing $4.5 million to develop a Center of Excellence in Genomic Testing in Cape Town, South Africa, to identify viral strains that pose a risk. Africa accounts for only 1% of over 3 million COVID-19 sequences conducted worldwide.

“Knowing which variants are circulating and where is critical for informing effective response operations,” WHO Africa Director Matshidiso Moeti said. “So, this groundbreaking initiative aims to initially support 14 Southern African countries to scale up their genomic sequencing by fifteenfold each month.”

Nkengasong said the pandemic has driven home the fact that African countries need to establish their own CDC-style agencies to drive surveillance and response to public health emergencies.

“It is no longer a theoretical concept that we must invest in our health systems,” Nkengasong said. “These are some of the key areas that are challenging countries, and we must invest in that space.”

Nearly 12% of Africa’s COVID-19 tests show positive results, a rate that is more than double the point where the WHO recommends complete societal lockdowns. African leaders show little desire to repeat the extreme measures they took early in the pandemic, however.

Partly for that reason, Nkengasong, Moeti and other public health experts in Africa continue to encourage people to use masks, hand-washing and social distancing to reduce the opportunities for the virus to spread.

But with pandemic fatigue undercutting those efforts, experts worry that another deadly wave of infections lies ahead during the holidays.

“With end-of-year travel and festive celebrations fast approaching, fresh increases in cases should be expected in the coming months,” said Benido Impouma, director of the Communicable and Non-communicable Cluster at WHO Africa.