• Scientists dispute claim that the low number of Covid-19 cases in Africa are due to poor surveillance and low testing.
• By end of last month, the case fatality rate globally was 6.5 per cent and three per cent in Africa.
Kenya may escape a full-blown Covid-19 pandemic partly because of its youthful population, warm weather and some assumed immunity gained through exposure to similar diseases, scientists have said.
They compared countries that have been devastated by the pandemic with African countries and ruled out low testing as the cause for low numbers.
Africa’s numbers are low in spite of less stringent lockdowns as seen in Europe and the United States, where the pandemic has killed hundreds of thousands of people.
“We argue that the low number of cases in Africa may not be an artifact of poor surveillance and low testing because an escalating number of Covid-19 cases would be easily detected through reports of pneumonia clusters at local hospitals, which has not been observed,” the scientists say, in a study published in the American Journal of Tropical Medicine and Hygiene.
Many public health experts around the world are still surprised that the deaths in Africa have not soared, given the high burden of diseases and high population density in urban informal settlements.
University of Nairobi epidemiologist Dr Mark Nanyingi and Washington State University’s Kariuki Njenga said despite this, the disease may not grow into a full-blown pandemic.
Part of the reason is the youthful population. Kenya's mean age is 20 years, Nigeria (18), compared to Italy’s median age of 45 years and 38 years in the US.
“This is a plausible argument, even though its contribution may be less because of other pervasive underlying factors such as malnutrition and risky livelihood,” they say.
Other experts are UoN’s Jeanette Dawa, and CF Otieno of the Jomo Kenyatta University of Agriculture and Technology; John Gachohi, Isaac Ngere, Michael Letko, Bronwyn Gunn, and Eric Osoro, all of the Washington State University Global Health Programme in Kenya.
The scientists also attribute the low rate of spread to warm weather between December and April.
“A recent regression analysis study comparing the effect of temperature on the number of Covid-19 cases across the 204 affected countries - exclusive of other possible factors - found countries with higher temperatures reporting lower infections, while those with lower temperatures serving as pandemic hotspots,” the study, titled ‘Why is There Low Morbidity and Mortality of Covid-19 in Africa?’, states.
However, this may mean cases in Kenya could rise as the cold weather sets in.
According to the Meteorological department, temperatures will fall this week, with most places across Kenya turning cold and dry for the next three months.
The Ministry of Health also projects this will fuel the spread, with cases peaking in August or September.
The authors also hypothesise that there was a low seeding rate in Africa, which means too few introductions to trigger a full-blown local epidemic.
The last hypothesis is that a population across Africa has some level of SARS-CoV-2 immunity because of prior exposure to other coronaviruses.
“Although a novel outbreak of coronavirus has not been reported in the region, the continuous contact between bats, livestock, and humans in rural Africa may have resulted in exposure to these emergent coronaviruses and development of humeral cross-reactivity,” the scientists say.
According to the World Health Organization, there are now more than over 150,000 confirmed cases of coronavirus across the continent.
Globally, there are more than 5.27 million cases.
By end of last month, the case fatality rate globally was 6.5 per cent and three per cent in Africa.
However, the Kenyan scientists warned that WHO still holds that Africa could still see increased cases and deaths, as demonstrated in Brazil, in the coming months.
"A progression that may dispel the hypotheses we deem compelling."
Edited by R.Wamochie