It occurred to me today that I hadn’t heard much about how previous flu-like pandemics have impacted African countries. Being a geographer at heart, I thought I’d look up some maps. I’m not an epidemiologist and am not making any predictions about how prior patterns of disease spread might replicate with the novel coronavirus / COVID-19.
I started with Wikipedia’s list of 20th and 21st century flu pandemics, and added seasonal influenza and severe acute respiratory syndrome (SARS), which isn’t the same as the flu. Let’s work backwards in time, since air travel has become much less expensive and more common since the 1980s, and this really changes the modality by which disease can spread between countries.
The three post-1980 epidemics are coronavirus (2020), H1N1 / swine flu (2009), and SARS (2003). Despite their weak health systems, African countries have not been highly affected by coronavirus to date. Transmission of H1N1 was also fairly limited, and transmission of SARS appears to have been almost non-existent. There’s a lot of debate about why coronavirus hasn’t spread, but two possibilities are the continent’s relatively weak air traffic links to other regions, and improvements in public health surveillance capability since 2000.
Coronavirus / COVID-19 (as of 12 March 2020)
H1N1 / swine flu (2009)
The pattern does look different for the seasonal flu. Unlike temperate climates, where flu actually is seasonal, flu cases are reported year-round in many African countries. Surveillance data on the flu in African countries is relatively weak and there are few country-specific flu vaccines available. It’s possible that cases of the flu are often misdiagnosed as malaria, which is also highly prevalent.
Seasonal flu (2011 – 2016)
Let’s look at the pre-1980 epidemics now. These include outbreaks of H1N1 / Russian flu (1977), H3N2 / Hong Kong flu (1968), H2N2 / Asian flu (1957), and H1N1 / Spanish flu (1918). I couldn’t find a good map for the Russian flu. For the other epidemics, I could only find maps tracing the path of the outbreak, rather than displaying the number of cases.
The 1968 Hong Kong flu looks fairly similar to the transmission path for coronavirus, in that Latin America and Africa seem to have been minimally affected. However, the 1957 Asian flu and the 1918 Spanish flu did impact Africa. I’m not sure about the mechanism by which the 1957 flu spread, but in 1918 the flu was spread by some of the two million African soldiers who returned home after being forced to fight for their colonizers during WWI. African countries had some of the highest mortality rates in the pandemic, with 2% of all Africans dying of the flu in only six months.
H1N1 / Spanish flu (1918)
There are many reasons why we can’t conclude very much about the spread of the novel coronavirus in Africa based on patterns of previous outbreaks. Transportation patterns, public health capacity, and the nature of the disease itself are all different for each pandemic. It’s still important for African countries to continue preparing their health systems for a more widespread coronavirus outbreak.