‘A ticking time bomb’: Scientists worry about coronavirus spread in Africa

CAPE TOWN, SOUTH AFRICA—Late on Sunday evening, South African President Cyril Ramaphosa, in a televised address to the nation, declared that COVID-19, the respiratory disease spreading globally, had become a “national disaster.” The declaration allows his government to access special funding and instigate harsh regulations to combat the viral outbreak. “Never before in the history of our democracy have we been confronted by such a severe situation,” Ramaphosa said before announcing a raft of measures to curb the virus’ spread, including school closures, travel restrictions, and bans on large gatherings.

So far, the official numbers seemed to suggest that sub-Saharan Africa, home to more than 1 billion people, had been lucky. The interactive map of reported COVID-19 cases run by Johns Hopkins University shows big red blobs almost everywhere—except sub-Saharan Africa.

But now the numbers are rising quickly. South Africa, which had its first case 10 days ago, now has 61. According to Ramaphosa, the virus has begun spreading inside the country. And just yesterday, Rwanda, Equatorial Guinea, and Namibia all reported their first cases, bringing the number of affected countries to 23. Some scientists believe COVID-19 is circulating silently in other countries as well. “My concern is that we have this ticking time bomb,” says Bruce Bassett, a data scientist at the University of Cape Town who has been tracking COVID-19 data since January.

And although Africa’s handling of the pandemic has received scant global attention so far, experts worry the virus may ravage countries with weak health systems and a population disproportionately affected by HIV, tuberculosis (TB), and other infectious diseases. “Social distancing” will be hard to do in the continent’s overcrowded cities and slums. “We really have no idea how COVID-19 will behave in Africa,” says pediatrician and HIV researcher Glenda Gray, president of the South African Medical Research Council. Last month, World Health Organization Director-General Tedros Adhanom Ghebreyesus, who is Ethiopian, said his “biggest concern” was COVID-19 spreading in countries with weak health systems. Sub-Saharan Africa detected its first case only on 27 February, in an Italian man who had traveled to Nigeria. Most other cases since then were imported from Europe; fewer came from the Americas and Asia. But until today, there were no examples of community spread. Screening passengers That’s not simply because of a lack of testing. More than 40 countries in Africa now have the ability to test for COVID-19, up from only two during the early stages of the outbreak in China. But the focus of African COVID-19 surveillance has been at countries’ points of entry, and testing has targeted people with a recent travel history to outbreak areas abroad. However, screening passengers for fever has shown to be largely ineffective, because it doesn’t catch people still in their incubation phase—up to 14 days for COVID-19. It also won’t detect cases that occur in African communities. “I do think that cases are slipping through the net. There is an urgent need to investigate and address this point,” says Francine Ntoumi, a parasitologist and public health expert at Marien Ngouabi University in the Republic of Congo. One way to find out whether the disease is spreading in the community is by looking at patients presenting with flulike illnesses at clinics and hospitals. The number of such patients isn’t increasing yet in Durban, which is in KwaZuluNatal, the province with South Africa’s highest HIV infection rate, says Salim Abdool Karim, director of the Centre for the AIDS Programme of Research in South Africa. Nor are they seeing a rise in older patients with acute respiratory distress. “Based on this, I feel reasonably confident that we do not have widespread community spread that is undetected,” Abdool Karim says. But he thinks it’s just a matter of time before imported cases of COVID-19—most of whom would be relatively wealthy people who can afford to travel—trickle down to the country’s most vulnerable communities. Patients who came from Europe will likely have interacted with South Africans prior to their diagnosis, including household help, who often take crowded minibuses to their homes in low-income areas—perfect conditions for COVID-19 to spread. “I think it is inevitable that we will have a substantial epidemic,” Abdool Karim says. Another way to reality-check reported COVID-19 cases is to scour surveillance systems that track influenzalike illnesses for unusual spikes. The Global Influenza Surveillance and Response System is showing elevated levels for some African countries, says John Nkengasong, director of the African Centres for Disease Control and Prevention (Africa CDC), which is based in Addis Ababa, Ethiopia. But that might be for reasons other than COVID-19, he says, like improvements in the quality of surveillance data. It’s also unclear how sensitive such detection methods are. In the United States, where the reported caseload is much higher than in Africa, scientists are seeing potential signals in data sets tracking influenzalike illness in older age groups, which are disproportionately afflicted by COVID-19, says Yale University epidemiologist Dan Weinberger. “But whether that is disease or increased health care seeking is another matter,” Weinberger tweeted in response to a question from Science . Africa CDC is working with countries to make sure samples sent to national surveillance sites that test negative for influenza or other known respiratory illness are screened for COVID-19 as well, Nkengasong says. “That may help provide further clarity on the question of possible undetected cases.”

We really have no idea how COVID-19 will behave in Africa. Glenda Gray, South African Medical Research Council