High SARS-CoV-2 seroprevalence in Health Care Workers but relatively low numbers of deaths in urban Malawi



Chibwana, Marah, Jere, Khuzwayo ORCID: 0000-0003-3376-8529, Kamn’gona, Raphael, Mandolo, Jonathan, Katunga-Phiri, Vincent, Tembo, Dumizulu, Mitole, Ndaona, Musasa, Samantha, Sichone, Simon, Lakudzala, Agness
et al (show 12 more authors) (2020) High SARS-CoV-2 seroprevalence in Health Care Workers but relatively low numbers of deaths in urban Malawi. medRxiv, 1 (08-04). 2020.07.30.20164970-.

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Abstract

<h4>Background</h4> In low-income countries, like Malawi, important public health measures including social distancing or a lockdown, have been challenging to implement owing to socioeconomic constraints, leading to predictions that the COVID-19 pandemic would progress rapidly. However, due to limited capacity to test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, there are no reliable estimates of the true burden of infection and death. We, therefore, conducted a SARS-CoV-2 serosurvey amongst health care workers (HCW) in Blantyre city to estimate the cumulative incidence of SARS-CoV-2 infection in urban Malawi. <h4>Methods</h4> Five hundred otherwise asymptomatic HCWs were recruited from Blantyre City (Malawi) from 22 nd May 2020 to 19 th June 2020 and serum samples were collected all participants. A commercial ELISA was used to measure SARS-CoV-2 IgG antibodies in serum. We run local negative samples (2018 - 2019) to verify the specificity of the assay. To estimate the seroprevalence of SARS CoV-2 antibodies, we adjusted the proportion of positive results based on local specificity of the assay. <h4>Results</h4> Eighty-four participants tested positive for SARS-CoV-2 antibodies. The HCW with a positive SARS-CoV-2 antibody result came from different parts of the city. The adjusted seroprevalence of SARS-CoV-2 antibodies was 12.3% [CI 9.0–15.7]. Using age-stratified infection fatality estimates reported from elsewhere, we found that at the observed adjusted seroprevalence, the number of predicted deaths was 8 times the number of reported deaths. <h4>Conclusion</h4> The high seroprevalence of SARS-CoV-2 antibodies among HCW and the discrepancy in the predicted versus reported deaths, suggests that there was early exposure but slow progression of COVID-19 epidemic in urban Malawi. This highlights the urgent need for development of locally parameterised mathematical models to more accurately predict the trajectory of the epidemic in sub-Saharan Africa for better evidence-based policy decisions and public health response planning.

Item Type: Article
Uncontrolled Keywords: COVID-19, IgG, Malawi, SARS-CoV-2, Seroprevalence
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences
Depositing User: Symplectic Admin
Date Deposited: 24 Nov 2022 10:10
Last Modified: 15 Mar 2024 04:24
DOI: 10.1101/2020.07.30.20164970
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3166357