Why have COVID-19 caseloads been comparatively low in Africa?

The global outbreak of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused the ongoing coronavirus disease 2019 (COVID-19) pandemic. To date, this virus has infected around 208 million individuals and has claimed more than 4.3 million lives. In African countries, more than 7.3 million COVID-19 cases have been reported.

Background

Recent data estimates that the African continent has accounted for just 4.1% of the total of 4.3 million deaths due to COVID-19. Earlier on in the pandemic, scientists had predicted a COVID-19 catastrophe in Africa, which is much more severe than what has actually been observed across the continent. South Africa is an exception and accounts for 35% of the confirmed cases and 42% of total deaths reported in 55 countries of the African continent.

The extensive spread and high disease burden were predicted based on transmission dynamics of the virus, socioeconomic deprivation, unsanitary living conditions, and poor healthcare systems throughout the African continent. Several small studies have been conducted in different parts of Africa, but these results were not validated in an Africa-specific context. Cross-reactivity with other micro-organisms and hypergammaglobulinemia due to malaria exposure may affect the sensitivity/specificity of these tests. This could further lead to underestimation or overestimation of seroprevalence.

Some studies have argued that factors like the demographic profile and early actions (e.g., lockdowns) are responsible for the lower COVID-19 burden, but there are still many questions unanswered. A new study has been published in the International Journal of Environmental Research and Public Health that highlights the potential lessons that the world can draw from Africa on assumptions concerning viral pandemics. This is particularly important, given Africa’s long experience with dangerous infectious diseases.

Why is the COVID-19 transmission rate low in Africa?

Many governments in Africa acted early to contain the pandemic, and on 22nd April 2020, the World Health Organization highlighted examples of how Africa was leading the global response. Measures such as early border closures, less international connectivity, and lockdowns helped lower the caseload.

Many models have shown a larger incidence of SARS-CoV-2 in urbanized regions, owing to dense living conditions. A large share of the African population (55%) lives in rural areas, leading to lower case numbers. In terms of demographics, only 3% of the African population is over 65, and they live at home with extended families. This is quite different from wealthy countries, where a large number of deaths have been owing to super-spreading events in care homes.

Research has also shown that proper ventilation can reduce the spread of the disease. Air conditioning and heating are completely absent in rural Africa, where most people live. Most Africans have an outdoor way of life, and they spend a majority of their time in fields, where the open-air significantly reduces the chances of viral transmission.

Factors influencing the low mortality rate in Africa

Demographics play an important role in reducing mortality from COVID-19. Research has shown that the demographic of 65–74 years is 35 times more likely to become hospitalized from SARS-CoV-2 infection and 1100 times more likely to die from COVID-19, compared to a reference demographic group of 5–17 years. Africa has quite a young population with a median age of 19.7 years. In comparison, some of the hardest-hit countries have much higher median ages (e.g., the median age in the UK is 40.5 years and in the USA is 38.5 years).

It is well documented that people with pre-existing conditions (e.g., diabetes, hypertension, etc.) have a higher risk of moderate to severe complications from COVID-19 infection. African countries have a low prevalence of these conditions, which might be another factor for the lower mortality rate.

Another factor that may be affecting the COVID-19 burden in Africa is “trained immunity.” Four key elements contributing to trained immunity in Africa are (i) prior vaccinations like BCG, (ii) exposure to various commensal microorganisms, (iii) prevalence of other infectious diseases, and (iv) use of herbal plants and natural remedies. Genetic factors might also be benefitting the African population. SARS-CoV-2 spreads through targeting the human angiotensin-converting enzyme-2 (ACE2) receptor. African individuals have been shown to have less expression of ACE2, making it difficult for the virus to infect cells.

Conclusion

The manner in which the COVID-19 pandemic has evolved in Africa has been quite different from the initial ‘doomsday’ predictions. This article discusses the factors that have contributed to low disease transmission and mortality. However, healthcare facilities are quite poor in the continent, and a third wave or the emergence of more infectious variants may severely challenge public health in this region. Vaccination remains a challenge, and less than 5% of the African people have received at least one vaccine dose. This is undoubtedly the area that needs immediate attention and improvement.

Journal reference:
Dr. Priyom Bose

Written by

Dr. Priyom Bose

Priyom holds a Ph.D. in Plant Biology and Biotechnology from the University of Madras, India. She is an active researcher and an experienced science writer. Priyom has also co-authored several original research articles that have been published in reputed peer-reviewed journals. She is also an avid reader and an amateur photographer.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Bose, Priyom. (2021, August 18). Why have COVID-19 caseloads been comparatively low in Africa?. News-Medical. Retrieved on June 28, 2022 from https://www.news-medical.net/news/20210818/Why-have-COVID-19-caseloads-been-comparatively-low-in-Africa.aspx.

  • MLA

    Bose, Priyom. "Why have COVID-19 caseloads been comparatively low in Africa?". News-Medical. 28 June 2022. <https://www.news-medical.net/news/20210818/Why-have-COVID-19-caseloads-been-comparatively-low-in-Africa.aspx>.

  • Chicago

    Bose, Priyom. "Why have COVID-19 caseloads been comparatively low in Africa?". News-Medical. https://www.news-medical.net/news/20210818/Why-have-COVID-19-caseloads-been-comparatively-low-in-Africa.aspx. (accessed June 28, 2022).

  • Harvard

    Bose, Priyom. 2021. Why have COVID-19 caseloads been comparatively low in Africa?. News-Medical, viewed 28 June 2022, https://www.news-medical.net/news/20210818/Why-have-COVID-19-caseloads-been-comparatively-low-in-Africa.aspx.

Comments

  1. Rob Polans Rob Polans United States says:

    It doesn't need attention, leave them alone.

  2. bill sailer bill sailer United States says:

    Bill, if BCG and other medications may have affected COVID,why not a medication that has been given free for 6 years, given to milliona and earned the Nobel Peach Prize for Merck???????

  3. bill sailer bill sailer United States says:

    Antivaxxers that have caught Covid and been cured do not comment.If they were happy they would be claiming that it is great to be unprotected.  But the only thing I have ever read was people who were dying, and say "I wish I took the vaccine"

  4. Michael Engel Michael Engel United States says:

    Everyone takes HCQ to prevent malaria.  Not a big mystery.  The real mystery is why they demonize this medicine.  It is proven.  It is safe.  They needed the pandemic. They will have many deaths on their hands

  5. Gary Doyle Gary Doyle United States says:

    Ivermectin is widely used for River Blindness in Africa. The American media calls Ivermectin "horse dewormer." It won a Nobel Prize for medicine in 2015 for human conditions, not animal.

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment
Post
You might also like...
Researchers compare the development and persistence of antibody and T-cell responses elicited by the mRNA BNT162b2 vaccine or SARS-CoV-2 infection