Leveraging Serosurveillance and Postmortem Surveillance to Quantify the Impact of Coronavirus Disease 2019 in Africa.

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has had a devastating impact on global health, the magnitude of which appears to differ intercontinentally: For example, reports suggest that 271 900 per million people have been infected in Europe versus 8800 per million people in Africa. While Africa is the second-largest continent by population, its reported COVID-19 cases comprise <3% of global cases. Although social and environmental explanations have been proposed to clarify this discrepancy, systematic underascertainment of infections may be equally responsible.

METHODS

We sought to quantify magnitudes of underascertainment in COVID-19's cumulative incidence in Africa. Using serosurveillance and postmortem surveillance, we constructed multiplicative factors estimating ratios of true infections to reported cases in Africa since March 2020.

RESULTS

Multiplicative factors derived from serology data (subset of 12 nations) suggested a range of COVID-19 reporting rates, from 1 in 2 infections reported in Cape Verde (July 2020) to 1 in 3795 infections reported in Malawi (June 2020). A similar set of multiplicative factors for all nations derived from postmortem data points toward the same conclusion: Reported COVID-19 cases are unrepresentative of true infections, suggesting that a key reason for low case burden in many African nations is significant underdetection and underreporting.

CONCLUSIONS

While estimating the exact burden of COVID-19 is challenging, the multiplicative factors we present furnish incidence estimates reflecting likely-to-worst-case ranges of infection. Our results stress the need for expansive surveillance to allocate resources in areas experiencing discrepancies between reported cases, projected infections, and deaths.

Informations de copyright

© The Author(s) 2022. Published by Oxford University Press on behalf of Infectious Diseases Society of America.

Déclaration de conflit d'intérêts

Potential conflicts of interest. N. E. K. reports occasional consulting for Abata Therapeutics in an unrelated field. D. S. reports previous employment at Pfizer Vaccines (until September 2021); current employment at Hillevax Inc; occasional consulting (until March 2022) through companies as Guidepoint, GLG, and Third Bridge; and stock options from Pfizer Inc and Hillevax Inc. C. V. reports an Elsevier contract for an editor-in-chief role with the journal Epidemics. M. L. reports research grants from the National Cancer Institute/NIH, the UK National Institute for Health and Care Research, the Morris-Singer Fund, the Open Philanthropy Project, the Centers for Disease Control and Prevention (CDC) (separately via Carnegie Mellon University and University of Utah), NIAID/NIH (via University of Michigan), Wellcome Trust, and Pfizer Inc; occasional consulting for Merck & Co, Inc, and Janssen Pharmaceuticals; speaking engagements with Bristol-Myers Squibb and Sanofi Pasteur; participation in the scientific advisory committee of the Coalition for Epidemic Preparedness Innovations; and serving as Director for Science at the CDC Center for Forecasting and Outbreak Analytics. M. S. reports research grants from NIH and Pfizer Inc. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.