Puzzled scientists seek reasons behind Africa’s low mortality rate
Dire predictions now look bizarre as infection rates continue to fall
Africa’s overburdened public health systems, dearth of testing facilities and overcrowded slums had experts predicting a disaster when Covid-19 hit the continent in February.
The new coronavirus was already wreaking havoc in wealthy Asian and European nations, and a UN agency said in April that, even with social distancing measures, it could kill 300,000 Africans this year.
In May the World Health Organisation (WHO) warned that 190,000 people on the continent could die if containment measures failed. Yet as the world marks 1-million Covid19 deaths, Africa is doing much better than expected, with a lower percentage of deaths than many other regions.
The continent’s case fatality count stands at 2.4%, with roughly 35,000 deaths among the more than 1.4-million people reported infected with Covid-19, according to Reuters data as at late Monday. In North America, it is 2.9% and in Europe 4.5%.
Hospitals in many African countries say Covid-19 admission rates are falling.
“Based on what we have seen so far it is unlikely that we are going to see anything at the scale we are seeing in Europe — both in terms of infections and mortality,” said Rashida Ferrand, a London School of Hygiene and Tropical Medicine professor working at the Parirenyatwa Group of Hospitals in the Zimbabwean capital Harare.
Experts say some Covid-19 deaths in Africa probably are being missed. Testing rates in the continent of about 1.3 billion people are among the lowest in the world, and many deaths of all types go unrecorded.
SA saw some 17,000 extra deaths from natural causes between early May and mid-July, 59% more than would normally be expected, according to a July report from the SA Medical Research Council.
That suggests the death toll from Covid-19 could be significantly higher than the official figure, currently over 16,000, researchers say. But even so, there is wide agreement that Covid-19 fatality rates have not so far been as bad as predicted.
Why? Scientists and public health experts cite a number of possible factors, including the continent’s youthful population and lessons learnt from previous disease outbreaks.
African governments also had precious time to prepare due to the relative isolation of many of their citizens from airports and other places where they could come into contact with global travellers. They also introduced lockdowns very early. SA had one of the most draconian in the world, introduced when there were just 400 confirmed infections countrywide.
Some scientists also are exploring the possibility that a tuberculosis vaccine routinely given to children in many African countries might be helping reduce deaths from Covid-19.
Another theory being considered is whether prior exposure to other coronaviruses including those that cause the common cold has provided a degree of resistance in some of the very communities once thought to be most vulnerable. “There is a lot of circumstantial evidence,” Salim Abdool Karim, a SA infectious disease specialist who has advised the government on Covid-19, told Reuters. “But there is no smoking gun.”
But others are more sceptical of these theories.
“All other regions have been exposed to coronaviruses, have poor people and slums and have received BCG vaccination,” said Humphrey Karamagi, team leader for data and analytics at the WHO’s Africa office. “We are most probably looking at a mix of multiple factors working together — and not a single magic bullet.”
For Sam Agatre Okuonzi, from the Arua Regional Referral Hospital in Uganda, the doomsday predictions were informed by entrenched prejudices, including that the continent is prone to disease.
“Covid-19 has shattered a lot of biases about disease in general but also about Africa,” he told Thursday’s briefing. “The severity of the pandemic has not played out in line with the outrageous predictions.”