By Dr Parkie Mbozi
ON 17th APRIL, 202O, the World Health Organisation (WHO) predicted that Africa’s coronavirus (or Covid 19) cases could hit 10 million in six months. meaning by October 17, 2020. And on July 22, 2020, our health minister Chitalu Chilufya told the nation through Parliament that Zambia could record 900 to 1,000 Covid-19 deaths per day by August 2020. Both WHO and Chilufya have been proved dead wrong and the gap between the projections and reality is staggering.
The question is, how has the pandemic defied all the predictions? In this article I look at some of the factors that the research community is advancing for the low cases of both incidences of, and mortality from, Covid 19 on the African continent.
This first case of Covid 19 on the African continent was reported in Egypt on 14th February 2020, followed by a one case in Algeria on 25th February. The first in sub-Saharan Africa was in Nigeria on February 28. Zambia reported its first twin cases on 18th March. Just two months after the first case was reported in Wuhan, China on 2nd December 2019, on 11th March the WHO Director General Dr Tedros, classified the COVID-19 outbreak as a global pandemic. By 1st April 2020, 46 sub-Saharan Africa countries had reported confirmed cases of COVID-19.
As the COVID-19 pandemic began to spread like wild fire across Europe and the America’s, many felt a sense of apprehension about what would happen when it reached Africa. Concerns over the combination of overstretched and underfunded health systems and the existing load of infectious and non-infectious diseases often led to it being talked about in apocalyptic terms. The WHO used the Maximum-Hasting (MH) parameter estimation method and the modified Susceptible Exposed Infectious Recovered (SEIR) models to project the spread of the COVID-19 pandemic on the African continent.
At the time WHO made the prediction of 10 million cumulative infections by mid-October,2020Africa had only recorded 19,000 infections and about 1,000 deaths. Zambia had recorded 52 cumulative cases of infections and two (2) mortalities. Going by the WHO projection, Zambia would have accumulated at least 28,000 cumulative infections by October 16.
In a statement published on 5th May 2020, WHO made an updated projection, covering the 12-month period May 2020 to April 2021. The statement said 83,000-190,000 people on the continent could die from the virus. It also underlined that 29 million to 44 million could become infected in the first year of the pandemic if containment measures fail. “There would be an estimated 3.6 million–5.5 million COVID-19 hospitalizations, of which 82, 000–167,000 would be severe cases requiring oxygen and 52,000–107,000 would be critical cases requiring breathing support,” it said
In Zambia’s case, Health Minister Dr. Chitalu Chilufya had warned that Zambia could suffer deaths of up to 1,000 daily by August due to Covid-19 if prevention guidelines were not adhered to. He identified funerals, Kitchen parties, church meetings, and other social gatherings as the main drivers of the pandemic in Zambia.
Addressing the nation through Parliament on 21st July 2020, Chilufya warned that based on the epidemiological modeling, Zambia’s peak Covid-19 month would be August. He projected that around 900 to 1,000 Zambians could die every day due to Covid-19 by August if people do not adhere to strict prevention measures. The spike in COVID-19 cases and deaths experienced at the time of his statement was partly due to the change in the weather and the possibility that the virus could have mutated.
Zambia’s cumulative total of infections stood at 3,386 and 128 deaths at the time of Chilufya’s projections. Two MPs had just died of COVID-19 and COVID-19 related complications.
The Gaps in Projections
Both WHO and Chilufya’s projections have been defied by Africa’s and Zambia’s Covid 19 infections and deaths and the gaps are wide.
As of 15th December 2020, Africa’s contribution to the global cumulative total of 71,351,695 cases of COVID-19 was a paltry 2,408,376 cases (about 3.3%); the rest of the world accounted for 97.7% (or 69,713,765). Africa’s 2,408,376 cases stunningly defy the projected 10 million cases by 15th October, according to WHO, even with the benefit of an additional two months (from 15th October todate).
Africa’s cumulative 57,072 deaths by 15th October represents a meagre 3.5% of the global total of 1,612,372. The rest of the world accounts for 96.5% of the total of the COVID-19 related deaths so far. Americas (North and South) account for the majority (50.5%) of global deaths, followed by Europe (27%).
On 15th December (two days ago), Zambia’s cumulative cases stood at 18,428. Compare this to WHO’s estimate of about 28,000 by 15th October. The official cumulative deaths as at 15th December were 368, compared to Chilufya’s 137,000 projection (at 1000 deaths per day starting on 1st August). What a gap and what a miss on Chilufya’s part! Deaths would have outstripped infections (according to the WHO estimates). How?
While Africa’s Covid 19 cases of the pandemic are reportedly steady and insignificant in most of the 55 countries, they are increasing and reaching record highs in many parts of Europe and the Americas, under what has been dubbed the ‘second wave’. In the USA, for instance, the Center for Disease Control (CDC) reports over 200, 000 daily infections and 1500 deaths, taking up its cumulative total to 308,091 deaths. The British authorities are worried about a mutation of the virus in Southern England, as the country has been placed in alert level 3. The Netherlands, Germany, France and others are also facing looming repeat lockdowns.
The question is, what accounts for Africa’s low Covid 19 incidences and deaths compared to the rest of the world? We can’t say it is effective health care systems and facilities because Africa has the least of the these. Nor can we say it is strict adherence to Covid 19 preventive and containment measures because there is hardly any of these in most countries, Zambia included as I have written many times before. So, what is it?
There has been much discussion on what accounts for the low incidences of and deaths from Covid 19 in Africa. Short of empirical data most of the propositions are speculative, at best intelligent assumptions (hypotheses). The plausible explanations that have been advanced so include: age, climatic differences, pre-existing immunity, genetic factors and behavioural differences. However preliminary data suggest that no single factor explains for the low Covid 19 on the continent, which prove the need for more focused correlation studies.
Even as the plausible factors have been advanced, the differences in social and biophysical conditions on the continent have been noted. As one group of scientists observes that. “Given the enormous variability in conditions across a continent – with 55 member states – the exact contribution of any one factor in a particular environment is likely to vary.”
The first and foremost argument is that Africa’s much younger population accounts for a very large part of the puzzle. Data across multiple countries show that the risk of dying of Covid-19 for those aged 80 years or more is around a 100 times that of people in their 20s. A group of Kenyan researchers have illustrated this with a specific example. As of 30th September, the United Kingdom (UK) had reported 41,980 Covid-19 specific deaths while Kenya, by contrast, had reported 691. The population of the UK is around 66 million with a median age of 40 compared with Kenya’s population of 51 million with a median age of 20 years.
In further regression analyses, the researchers still concluded that even if the UK was to be accorded the same age structure as Kenya’s, its deaths would still be around 5000 Covid 19, compared to Kenya’s 700 at the time. The question then is, what might account for the disproportion?
That leads to the second hypothesis/factor: the weather. A recent large multi-country study in Europe reported significant declines in mortality related to higher temperature and humidity. The authors hypothesised that this may be because the mechanisms by which our respiratory tracts clear viruses work better in warmer and more humid conditions. This means that people may be getting less virus particles into their system.
There is a problem was link between weather and Covid 19 though. A systematic review of global data – while confirming that warm and wet climates seemed to reduce the spread of COVID-19 – indicated that these variables alone could not explain most of the variability in disease transmission. Worth of note, however, is that there’s considerable weather variability throughout Africa. The higher cases in some North African countries and in some South Asian countries, notably India, tend to invalidate the weather argument. About 68% of the African cases are coming from the five countries in the following order – South Africa (873,679), Morocco (327 528), Egypt (122,609), Ethiopia (117,542) and Tunisia (113,241). Most of these are relatively warmer and humid countries.
The possibility (perhaps reality) of failure to identify and record deaths and low testing in Africa has also been advanced. The counter argument is that even with limited testing, Covid 19 cases would still manifest in terms of BIDs (brough-in-dead) if cases were very high in communities. Our burial sites would have also been over-stretched and new ones created as we have seen in other countries. Kenyan scientists have given an example of their country which, as with most countries, initially had little testing capacity and specific death registration. However, Kenya quickly ramped up its testing capacity and extra attention to finding and recording deaths. This ruled out the possibility low deaths can be fully accounted for by missing information.
There has been no shortage of ideas for other factors that may be contributing. Other suggestions include the possibility of pre-existing protective immune responses due either to previous exposure to other pathogens or to BCG vaccination, a vaccine against tuberculosis provided at birth in most African countries. A large analysis – which involved 55 countries, representing 63% of the world’s population – showed significant correlations between increasing BCG coverage at a young age and better outcomes of COVID-19.
Other factors such as relatively low cases in Africa of pre-existing conditions, such as non-communicable diseases – e.g. hypertension, caners, diabetes, etc.
While the need for more research on Africa’s low Covid 19 cases is indisputable, the staggering failure of the modeling systems to correctly approximate the spread of the pandemic on the continent and, particularly, in Zambia, is puzzling. In all fairness our Ministry of Health owes us an explanation on what was the basis of the alarmist statement Chilufya issued on 21st July.