SARS-CoV-2 Seroprevalence in a Rural and Urban Household Cohort during First and Second Waves of Infections, South Africa, July 2020-March 2021

Emerg Infect Dis. 2021 Dec;27(12):3020-3029. doi: 10.3201/eid2712.211465. Epub 2021 Sep 3.


Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections may be underestimated because of limited access to testing. We measured SARS-CoV-2 seroprevalence in South Africa every 2 months during July 2020-March 2021 in randomly selected household cohorts in 2 communities. We compared seroprevalence to reported laboratory-confirmed infections, hospitalizations, and deaths to calculate infection-case, infection-hospitalization, and infection-fatality ratios in 2 waves of infection. Post-second wave seroprevalence ranged from 18% in the rural community children <5 years of age, to 59% in urban community adults 35-59 years of age. The second wave saw a shift in age distribution of case-patients in the urban community (from persons 35-59 years of age to persons at the extremes of age), higher attack rates in the rural community, and a higher infection-fatality ratio in the urban community. Approximately 95% of SARS-CoV-2 infections were not reported to national surveillance.

Keywords: COVID-19; SARS-CoV-2; South Africa; coronavirus disease; coronaviruses; infection–case ratio; infection–fatality ratio; infection–hospitalization ratio; respiratory infections; seroprevalence; severe acute respiratory syndrome coronavirus 2; viruses; zoonoses.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • COVID-19*
  • Child
  • Humans
  • Middle Aged
  • Rural Population
  • SARS-CoV-2*
  • Seroepidemiologic Studies
  • South Africa / epidemiology