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 done 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.”