Africa has been spared so far from coronavirus. Why?

UPDATE: SINCE PUBLICATION, AFRICA HAS REPORTED IT FIRST CASE OF CORONAVIRUS: Africa confirms first case of coronavirus

About 2 million Chinese live and work on the African continent. Africans are also increasingly visiting China for business and study.

Before the novel coronavirus outbreak — which is centered on China's Hubei region and its provincial capital of Wuhan — about eight flights a day operated between China and African nations.

Chinese travelers made up the biggest group of customers on Ethiopian Airlines, Africa's largest carrier, according to Quartz Africa.    

This booming travel between China and Africa is a possible route for transmission of the new coronavirus, which has killed 1,369 people and infected 46,997 globally, according to the latest WHO figures.

So why has Africa been spared so far?

Limited testing

A simple explanation, say public health experts, could be that the continent simply hasn't had the ability to detect cases up until now.

As of late last week, only two African countries — Senegal and South Africa — had laboratories capable of testing and confirming samples for the virus.

"We can't tell if we have had cases of the novel coronavirus and are missing them; perhaps these cases have come and we didn't detect them," said Isaac Ngere, a Kenyan-based researcher specializing in the outbreak of diseases.

This situation has changed. Medical teams from more than a dozen African countries met in Senegal last week to learn how the diagnose the new virus. Now 19 African nations are able to test for COVID-19, including Nigeria, Gabon, Cameroon, Ethiopia, Kenya, Zambia and Sierra Leone, WHO Africa clarified in an email.

The World Health Organization (WHO) has also identified 13 priority countries in Africa with strong links to China and told DW it has dispatched experts to eight of these to help coordinate preparedness efforts.

The priority countries have all introduced screenings at airports, as well as some seaports, according to the WHO.

In Sierra Leone, more than 30 Chinese who arrived from China last week are under quarantine in Freetown.

"Anyone from China, whether a Chinese diplomat, a Sierra Leonean or Nigerian, as long as your passport shows you left China within past 14 days — as soon as you enter any of our border crossing points, we would detain and put you in quarantine, said Dr. Mohamed Alex Vandy, Sierra Leone's Director of Health Security Emergency Management.

"Not because you are sick or committed any crime, but as a preventive measure to keep the population safe."

With screening on the rise and testing capabilities in place, now perhaps we will see a difference in terms of detecting cases, disease researcher Isaac Ngere told DW.

'Pure chance'

Paul Hunter, a UK-based specialist in infectious diseases and epidemics, largely puts the absence of COVID-19 on the continent down to luck.

"If you look at how COVID-19 has spread to non-Chinese countries, most of the spread has been pretty much due to the general intensity of travel around the world," he told DW.  

"There is nothing special about Africa not having seen a case other than pure chance at the moment."

Too warm for COVID-19?

Another theory is that the continent is too warm for the COVID-19 virus to thrive.

Coronaviruses, which include some of the viruses responsible for the common cold and flu, can show something called seasonality — that is, they peak and wane depending on the season.

Many cold and flu viruses peak in winter, for example; the droplets sneezed and coughed out by people spread more easily in winter's cold dry air and when people are crowded inside together.

They then die down in warmer weather.

"When the season is warmer and more humid, the droplets transmitting the [flu virus] tend to fall out of the air more quickly, therefore limiting its transmission," explained Yap Boum, the Africa representative for Epicentre, the research arm of Doctors without Borders (MSF).

Tropical countries aren't immune from seasonality, with flu peaking in the dry season in countries like Cameroon, Boum told DW.

However, not all coronaviruses spread through respiratory droplets and Boum cautions that it is too early to tell if COVID-19 is transmitted in a similar fashion.

"We have no background information ... so we can't yet tell," he said.

However, he said, it still "might be more prudent for countries like South Africa, which will start heading into winter, to follow how the winter will affect or not the transmission of the novel coronavirus."  

'Doubt a big outbreak in Africa'

Epidemiologist Paul Hunter also emphasizes that the COVID-19 virus "hasn't been around long enough" to know if its transmission will be affected by a change in seasons.

But even if the coronavirus makes its way to Africa, Hunter doesn't believe the continent will be as hard hit as China.

Read more: Africans in Wuhan: Homesick and fearful of coronavirus 

"I doubt we will see a big outbreak in Africa," said Hunter, a medical professor at the University of East Anglia as well at Tshwane University of Technology in South Africa.

"Droplet diseases don't seem to be as big an issue in Africa," he said, adding that SARS, a respiratory disease that is also a coronavirus, spread through 26 countries in 2003 but failed to gain a hold in Africa. Influenza epidemics are also less intense on the continent, he pointed out.

In addition, in Africa people generally don't live crammed together in such densely populated areas and they also spend a lot more time out-of-doors in Africa than they do in northern countries.

"I think that mitigates against such a severe outbreak," Hunter told DW.

No evidence of African immunity

There have been rumors swirling on social media that African countries haven't seen a case of coronavirus yet because Africans are immune.

Disease experts emphatically reject this idea.

"That is nonsense. There is no evidence what so ever. That is false news, false facts," said infectious disease specialist Paul Hunter.  

As for Dr Ngere, he said rumors that Africans have a genetic immunity to the disease are "entirely not true!"

Claudia Anthony in Freetown contributed to this report.