How do we explain the low Covid-19 caseload in Africa (so far)?

According to the Africa Centres for Disease Control, 52 African countries had reported 13,686 cases (the majority of which were imported cases) of Covid-19, including 744 deaths, as of 12 April 2020. These numbers were 0.7% and 0.6% of the global Covid-19 cases and casualties of 1,804,748 and 110,877 respectively.

Why are there so few Covid-19 cases in Africa, a continent bigger than China, the US and Canada combined?

Many suggest the low caseload is because of inadequate testing facilities due to scarce resources and weak healthcare systems in Africa (see also here and here). However, we have made some other observations, related to demographics, behavioural patterns, age dynamics, climate and other factors, that could be keeping the overall caseload low in Africa. A study of these observations might catalyse some intriguing research as the world grapples to combat a common enemy that does not respect religious affiliation, economic status or geographic boundary.

Low population density

A low population density in Africa, just 117 people per square mile, is much lower than in other regions of the world. For example, the population density in Western Europe and Southeast Asia is 468 per square mile and 399 people per square mile, respectively. Similarly, in crowded regions of the US, such as in New York state, which has become an epicentre of Covid-19, population density is as high as 421 per square mile.

A high population density implies people reside close to each other and chances of them interacting with each other are very high. Such interaction during a pandemic can accelerate spread of the disease.

This logic also applies to Africa, where some countries, for example, South Africa, Egypt, Morocco and Algeria, have crowded and highly urbanised settlements, unlike the pastoral situation in much of the rest of Africa. As of 12 April, these four countries had reported relatively high Covid-19 counts — 7,409 cases and 559 deaths — as compared to southern, eastern, and central Africa, which had reported only 35, 27 and 38 Covid-19 casualties, respectively.

Less movement

While there are almost borderless, regional economic communities and political free-trade blocs (IGAD, SADC, AMU, ECOWAS, ECCAS, CEN-SAD), movement to and from the African continent is relatively limited compared to other continents. A careful look at flight data shows African airports experience the fewest number of intercontinental incoming flights.

Apart from OR Tambo International Airport in Johannesburg, no airport in Africa makes it onto the list of top 50 busiest airports in the world. The consequence is evident in South Africa’s Covid-19 cases topping 2,000, while cases in many other African countries have not reached 50.

Regional hubs Addis Ababa, Nairobi, Johannesburg, Abuja and Cairo, have imposed varying levels of international flight bans and the restricted movement has clearly kept down transmission into the continent.

Low proportion of old people

Covid-19 is more dangerous for people aged above 65. In Italy, which has been hardest hit, the population ratio of 65 or above is 23.1%. In Africa it is below 5%. Africa’s youth, below 25 to be exact, is 60% of the population of the continent. This demographic appears to be a protection factor.

Good communal health-seeking behaviour

Africans have adopted good communal health-seeking behaviour over time, primarily due to the history, extent and nature of social development movements and awareness, both by NGOs (including UN bodies) and faith-based institutions. Also, following two recent deadly epidemics — Ebola virus and Congo virus — Africans have become more responsive to local government calls for caution during disease outbreaks. Such behaviour is less common in Europe. For instance, people in Italy and the UK initially ignored government appeals to maintain social distancing. The number of Covid-19 cases in those countries quickly multiplied.

Possible immunity due to existing disease trends

Initial research indicates a negative correlation between the occurrence of malaria and Covid-19 in a region. Malaria-affected countries seem to be relatively safer from Covid-19, and vice versa. The figure below shows this correlation.

Blue depicts places where malaria has caused more than 0.1 deaths per million inhabitants. Yellow shows regions where Covid-19 has caused a similar level of fatalities. (Source: Guerrini et al, 2020)