SARS-CoV-2 Prevalence in Malawi Based on Data from Survey of Communities and Health Workers in 5 High-Burden Districts, October 2020
Joe Alex Theu, Alinune N. Kabaghe, George Bello, Evelyn Chitsa-Banda, Matthews Kagoli, Andrew F. Auld, Jonathan Mkungudza, Gabrielle O’Malley, Fred Fredrick Bangara, Elizabeth Peacocke, Yusuf Babaye, Wingston Ng’ambi, Christel Saussier, Ellen MacLachlan, Gertrude Chapotera, Mphatso D. Phiri, Andrea A. Kim, Mabvuto Chiwaula, Danielle Payne, Nellie Wadonda-Kabondo, Annie Chauma-Mwale, Titus Divala
Abstract
To determine early COVID-19 burden in Malawi, we conducted a multistage cluster survey in 5 districts. During October-December 2020, we recruited 5,010 community members (median age 32 years, interquartile range 21-43 years) and 1,021 health facility staff (HFS) (median age 35 years, interquartile range 28-43 years). Real-time PCR-confirmed SARS-CoV-2 infection prevalence was 0.3% (95% CI 0.2%-0.5%) among community and 0.5% (95% CI 0.1%-1.2%) among HFS participants; seroprevalence was 7.8% (95% CI 6.3%-9.6%) among community and 9.7% (95% CI 6.4%-14.5%) among HFS participants. Most seropositive community (84.7%) and HFS (76.0%) participants were asymptomatic. Seroprevalence was higher among urban community (12.6% vs. 3.1%) and HFS (14.5% vs. 7.4%) than among rural community participants. Cumulative infection findings 113-fold higher from this survey than national statistics (486,771 vs. 4,319) and predominantly asymptomatic infections highlight a need to identify alternative surveillance approaches and predictors of severe disease to inform national response.