While testing has been comparatively limited, the continent appears to have bucked the doomsday predictions of global health experts. The telltale signs of severe outbreaks seen elsewhere — crowded hospitals and a spike in deaths — have emerged in only a handful of African countries. Surveys by the World Health Organization have found negligible excess mortality rates in most African countries, reducing suspicion that many covid-19 deaths are going uncounted.
Data is scant, as are peer-reviewed studies. But even as more research emerges, public health experts caution that the explanation for why Africa’s caseload has remained low will be complicated.
“It is highly unlikely that there is a single, definitive answer as to why this is the case,” said Ngoy Nsenga, a Congolese epidemiologist and the WHO’s program manager for emergency response in Africa. “Youthful populations, warmer climates, less time indoors, less traveling, less obesity and diabetes, immunities derived from other diseases — even other coronaviruses — are all playing a part, we think. But what distinguishes Africa from other places like Brazil that might share those factors, but were still hard-hit, are our human interventions.”
Almost all African countries closed their international borders early in the pandemic. Many imposed localized lockdowns, curfews and bans on social activities such as bar-going even before notching their first cases. Nsenga and other experts agreed that while adherence to other mandates such as mask-wearing and social distancing may have been lax, their early implementation along with more heavy-handed measures were effective at flattening the curve of infections.
Those interventions have exacted immense economic damage, however, and with many African governments not seeing uncontrolled growth in cases, they have been rolled back in many places.
Ghana, Senegal and Cameroon, for instance, have shuttered some special treatment centers, citing a consistent lack of patients in need.
Officials in the Cameroonian capital, Yaoundé, had turned a soccer stadium into a quarantine facility, fearing the worst. Athletes reclaimed it three months ago.
In Senegal, the number of covid-19 treatment centers has dropped from 23 to 14.
Restaurants are crowded. Nightclubs, too. Local DJs have resumed their all-night dance parties on the beach.
Health officials, however, caution that the threat is far from over — even if hospitals aren’t filling up.
“During the holiday season, there will be a tendency for large movement from capital cities to villages, remote areas, for people to connect with families. That might drive the pandemic,” John Nkengasong, director of the Africa CDC, told reporters this week. Africa is recording 10,000 to 12,000 cases daily, moving back toward a July peak of 14,000.
Ndongo Dia, head of the respiratory virus diagnostic laboratory at the Pasteur Institute in Senegal’s capital, Dakar, isn’t sure why Senegal dodged the worst of the pandemic.
The nation has garnered widespread praise for its quick response, which included sealing its border, rolling out four-hour tests while Americans waited days for results, and imposing a curfew until infections slowed.
Beyond that, Dia said, “our luck is the composition of our population. The number of severe cases is going to be much lower compared to the northern countries, where there are more elderly people.”
Almost 60 percent of people in sub-Saharan Africa are younger than 25, and only 3 percent are over 65, the age group in which illness and death from the coronavirus are most common.
Death rates have been higher in South Africa, Algeria, Egypt and Tunisia, where a larger percentage of the population is over 65. Those four countries account for two-thirds of all coronavirus deaths in Africa.
Preliminary analyses by the WHO indicate that Africans may be twice as likely to contract the coronavirus without experiencing any illness, and that more than 80 percent of cases on the continent have been asymptomatic — a far higher percentage than elsewhere in the world.
One set of hypotheses that many African epidemiologists said deserve greater study was whether exposure to other infectious diseases, which are rife in Africa — or their vaccines, which many receive at birth — could have conferred some level of immunity against the novel coronavirus.
“We are exposed quite often to a large number of bugs and pathogens: malaria, typhoid, meningitis and more,” said Yap Boum, a Cameroonian epidemiologist and regional representative for Epicenter Africa, the research arm of Doctors Without Borders, “which might be different to what you have in the U.S. and Europe and other places.”
Nsenga, the WHO’s emergency program manager, said that while many factors could be at play, some seemed to be out of the question.
“It is not different strains — that I can refute. We have a network of laboratories all over the continent and the world,” he said. “We have sequenced from many places. We haven’t seen dramatically different strains here.”
Strain sequencing has also played a role in contact tracing. Very few countries in Africa have effectively contact-traced covid-19 patients, but in Nigeria, close monitoring of case clusters was used to redesign interventions to fit common patterns of the virus’s spread.
Researchers acquired DNA samples from people who tested positive and, as of this week, have discovered 13 coronavirus strains in Nigeria alone. It is a method that epidemiologists there have learned after suffering repeated outbreaks of deadly diseases including Ebola and Lassa fever.
“We have been dealing with epidemics and outbreaks for decades,” said Christian Happi, director of the African Center of Excellence for Genomics of Infectious Diseases in the southwestern Nigerian town of Ede. “People learn how to deal with diseases better than countries that have not experienced that kind of thing.”
Paquette reported from Dakar, Senegal. Borso Tall in Dakar contributed to this report.