A study conducted by the World Health Organization (WHO) has predicted that the coronavirus will infect almost one-quarter of a billion people in Africa during the first year of the pandemic. Unless immediate measures are taken to control the spread of the virus, as many as 190,000 of them are likely to die, the researchers warn.
Study: The potential effects of widespread community transmission of SARS-CoV-2 infection in the WHO African Region: a predictive model. Image Credit: Lorna Roberts / Shutterstock
The predictive modeling study indicated that the risk of exposure and transmission in the WHO African Region is actually lower than in other areas of the world. However, the increase in hospital admissions, as well as the impact on care systems and other health conditions, would place a significant strain on already limited resources and exacerbate the effects of the virus.
Joseph Cabore, Director of Programme Management for the World Health Organization Regional Office for Africa, and colleagues say successful containment measures are essential for the region "as their health systems are not designed to mitigate against the implications of widespread community transmission of SARS-COV-2 [severe acute respiratory syndrome coronavirus 2]."
They warn it is essential that countries in the WHO African Region ensure that hospital capacity is increased and that basic emergency care needs are catered for by healthcare services.
The unprecedented and widespread effect of SARS-CoV-2 and the associated coronavirus disease 2019 (COVID-19) have led to considerable efforts being made globally to curb transmission. The impact of the virus extends beyond the number of infection cases and deaths to widespread disruption of health services' ability to provide care in general.
The pandemic has affected every country in the world, with the whole of the globe's population at risk of infection and death. However, transmission rates and health outcomes have differed between countries, which suggests that variations in socio-ecological factors and individuals' susceptibility play a role in influencing infection rates.
Previous predictive models
Forty-seven countries are included in the WHO Africa region, 45 of which had reported SARS-CoV-2 infections as of 29th April.
Many predictive models have been developed to estimate transmission and mortality rates in Africa. However, the models have not sufficiently incorporated the various social, environmental, and health-related factors that differ across different countries in the region, leading to varied projections of viral spread and the severity of its impact.
The model used for the current study
As reported in a study accepted for publication in BMJ Global Health, Cabore and colleagues developed a predictive model that incorporated these factors to improve the accuracy of the estimated effects of SARS-CoV-2 transmission.
The model "uses both virus transmission characteristics and country-specific socio-ecological factors to predict the most likely outcome of widespread and sustained community transmission of SARS-CoV-2," writes the team.
What did the study find?
The model predicted that the infection would spread more slowly in Africa than in other countries, causing fewer cases of severe illness and death, owing to differing degrees of individual susceptibility between countries. However, it also predicted that the pandemic would linger for a more extended period and possibly remain a threat for some years.
The estimates suggested that without sufficient control measures being implemented, the exposure risk would be higher in small countries, with Mauritius probably being the most susceptible.
Of the larger countries, South Africa, Cameroon, and Nigeria would be the most at risk, and Nigeria would have the most infections. After Nigeria, the infection number would be highest in Algeria and South Africa. The lowest number of cases would be seen in Mauritania, followed by Seychelles and Eritrea.
The highest proportion of infected people per capita would be seen in Mauritius, Seychelles, and Equatorial Guinea, and the lowest proportion would be seen in Niger, Mauritania, and Chad.
During the first year of the pandemic, about one in four of the region's 1 billion people would become infected, with the number of symptomatic individuals potentially reaching 44 million.
As many as 5.5 million may require hospitalization, 140,000 would have severe disease, and about 89,000 cases would be critical. An estimated 150,000 would lose their lives, but the authors say this number could reach 190,000.
A "limited capacity to mitigate against the disease effects"
Although only 22% of the population would be infected during the first year and the number of severe cases and deaths would be fewer than in other areas of the world, "the increase in hospitalizations and care needs and impacts on morbidity and mortality of other conditions would have significant effects due to limited capacity to mitigate against the disease effects," warns the team.
Some hospitalizations would be required in areas with limited access to healthcare systems, and inadequate testing and collection of data, especially in rural settings, would make response efforts difficult.
"These system capacity challenges highlight the need to ensure the success of the containment measures to avoid the need for mitigation measures that, despite relatively fewer cases expected in the Region, will be difficult to institute," writes the team.
These mitigation measures would place a significant strain on healthcare systems, primarily secondary and tertiary services, and inadequate testing and diagnostic capacity could mean many cases go unidentified in primary care settings.
"The effect of avoiding widespread and sustained community transmission of SARS-CoV-2 is significant, and most likely outweigh any costs of preventing such a scenario," say Cabore and colleagues.
"Countries of the WHO African Region need to expand the capacity of particularly their primary hospitals to mitigate implications of widespread community spread of SARS-CoV-2. Basic emergency care needs to be included in primary care systems," the team concludes.