The trajectory of the SARS-CoV-2 pandemic in sub-Saharan Africa (SSA) is uncertain. To date, reported case counts and mortality in SSA have lagged behind other geographical regions. All SSA countries, with the exception of South Africa and Ethiopia, reported fewer than 100,000 total cases and fewer than 1,800 deaths as of December 2020 – totals far lower than observed in Asia, Europe and the Americas.
However, variation in reporting between countries and some seroprevalence surveys that suggested high rates of local infection make it unclear if the relatively few reported cases and deaths to date indicate a generally reduced epidemic potential in SSA at researchers led by Benjamin Rice at the department of ecology and evolutionary biology, Princeton University, and the Madagascar Health and Environmental Research.
Study details
Variation in SARS-CoV-2 outbreaks across sub-Saharan Africa
Benjamin L Rice, Akshaya Annapragada, Rachel E Baker, Marjolein Bruijning, Winfred Dotse-Gborgbortsi, Keitly Mensah, Ian F Miller, Nkengafac Villyen Motaze, Antso Raherinandrasana, Malavika Rajeev, Julio Rakotonirina, Tanjona Ramiadantsoa, Fidisoa Rasambainarivo, Weiyu Yu, Bryan T Grenfell, Andrew J Tatem, C Jessica E Metcalf
Published in Nature Medicine on 2 February 2021
Abstract
A surprising feature of the SARS-CoV-2 pandemic to date is the low burdens reported in sub-Saharan Africa (SSA) countries relative to other global regions. Potential explanations (for example, warmer environments1, younger populations2,3,4) have yet to be framed within a comprehensive analysis. We synthesized factors hypothesized to drive the pace and burden of this pandemic in SSA during the period from 25 February to 20 December 2020, encompassing demographic, comorbidity, climatic, healthcare capacity, intervention efforts and human mobility dimensions. Large diversity in the probable drivers indicates a need for caution in interpreting analyses that aggregate data across low- and middle-income settings. Our simulation shows that climatic variation between SSA population centers has little effect on early outbreak trajectories; however, heterogeneity in connectivity, although rarely considered, is likely an important contributor to variance in the pace of viral spread across SSA. Our synthesis points to the potential benefits of context-specific adaptation of surveillance systems during the ongoing pandemic. In particular, characterizing patterns of severity over age will be a priority in settings with high comorbidity burdens and poor access to care. Understanding the spatial extent of outbreaks warrants emphasis in settings where low connectivity could drive prolonged, asynchronous outbreaks resulting in extended stress to health systems.
[link url="https://www.nature.com/articles/s41591-021-01234-8"]Nature Medicine study (Restricted access)[/link]