What is the prevalence of COVID-19 detection by PCR among deceased individuals in Lusaka, Zambia? A postmortem
Christopher J Gill1, Lawrence Mwananyanda2, William B MacLeod2
1Department of Global Health, Boston University School of Public Health, Boston, Massachusetts, USA cgill@bu.edu.
Objectives:
To determine the prevalence of COVID-19 postmortem setting in Lusaka, Zambia.
Design:
A systematic, postmortem prevalence study.
Setting:
A busy, inner-city morgue in Lusaka.
Participants:
We sampled a random subset of all decedents who transited the University Teaching Hospital morgue. We sampled the posterior nasopharynx of decedents using quantitative PCR. Prevalence was weighted to account for age-specific enrolment strategies.
Interventions:
Not applicable-this was an observational study.
Primary Outcomes:
Prevalence of COVID-19 detections by PCR. Results were stratified by setting (facility vs community deaths), age, demographics and geography and time.
Secondary Outcomes:
Shifts in viral variants; causal inferences based on cycle threshold values and other features; antemortem testing rates.
Results:
From 1118 decedents enrolled between January and June 2021, COVID-19 was detected among 32.0% (358/1116). Roughly four COVID-19+ community deaths occurred for every facility death. Antemortem testing occurred for 52.6% (302/574) of facility deaths but only 1.8% (10/544) of community deaths and overall, only ~10% of COVID-19+ deaths were identified in life. During peak transmission periods, COVID-19 was detected in ~90% of all deaths. We observed three waves of transmission that peaked in July 2020, January 2021 and ~June 2021: the AE.1 lineage and the Beta and Delta variants, respectively. PCR signals were strongest among those whose deaths were deemed 'probably due to COVID-19', and weakest among children, with an age-dependent increase in PCR signal intensity.
Conclusions:
COVID-19 was common among deceased individuals in Lusaka. Antemortem testing was rarely done, and almost never for community deaths. Suspicion that COVID-19 was the cause of deaths was highest for those with a respiratory syndrome and lowest for individuals <19 years.
