Low Covid-19 impact on Africa baffles scientists

As Covid-19 was battering Europe and the Americas, leaving behind thousands dead and the healthcare system stretched to the limits, experts were giving a grim picture of the pandemic for Africa.

“African countries need to wake up to the increasing threat… The best advice for Africa is to prepare for the worst and prepare today,” Tedros Adhanom Ghebreyesus, the director-general of the World Health Organization (WHO) said then.

In Kenya, crowded neighbourhoods that prevented social distancing, poor or non-existent healthcare systems, and poor hygiene were said to be accelerators to the spread and expected high fatalities.

Five months in, and with over 35,101 cases and 597 deaths, Kenya and Africa have “beaten the odds”, leaving experts scratching their heads.  According to a Kenya Medical Research Institute (Kemri) and the Health ministry study, the peak happened before the end of July in what they term as “some major urban counties”, with between 34 and 41 per cent of residents being infected. Their analysis suggests the Covid-19 disease burden in Kenya may be far less than initially feared.

So how was Africa spared the worst?  According to WHO, this is due to its relatively young population, with over 60 percent being under 25.

First three months

In the first three months following the outbreak, nearly one million people were infected and 50,000 died. By six months, the number of cases exceeded 10 million and there were more than 500,000 deaths.

One of the troubling observations about Covid-19 is that infected people—some scientists estimate up to 40 percent—can transmit the virus to others before they have symptoms or without ever having symptoms.

Speaking to the Nation, Dr Ojal said that, at this point, the team was not certain about the factors that have led to the observed low cases of severe Covid-19 and deaths despite the widespread exposure.

According to some scientists who did not take part in the Kemri study, there are four things that might have slowed down the progression of Covid-19 in Africa—cross-immunity from other coronaviruses which have seen population build immunity; the continent’s youthful population; temperate climate; and exposure to some diseases that are not present in the West.

Dr Eddy Odari, a medical virologist and a lecturer at the department of microbiology at the Jomo Kenyatta University of Agriculture and Technology (JKUAT) argues that while Africa did not register any cases of severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), which also are caused by coronaviruses, evidence shows that many people developed an immune response, which could have contributed to the low infection rates.

Considerable deaths

Of the seven coronaviruses associated with disease in humans, three (SARS-CoV, MERS-CoV, and SARS-CoV-2) cause considerable deaths but also share significant the same or a similar relation (sequence homology), which Dr Odari, a medical virologist explains “is capable of stimulating an immune response (antigenic epitopes) towards other coronaviruses.”

These parameters are then used to assess the relationship between certain antigens.

“We cannot downplay the impact that early interventions taken by governments before the first case was confirmed in the continent,” said Dr Kyobutungi, the Executive Director of the African Population and Health Research Centre.

aolingo@ke.nationmedia.com, emerab@ke.nationmedia.com

Credit: Source link