SARS-CoV-2 seroprevalence and respiratory disease disability claims in Mexico City Metropolitan Area

Objective. To characterize the impact of SARS-CoV-2 infection in workers from an essential large-scale company in the Greater Mexico City Metropolitan Area using point prevalence of acute infection, point prevalence of past infection through serum antibodies and respiratory disease short-term disability claims (RD-STDC). Materials and methods. Four randomized surveys, three during 2020 before and one after (December 2021) vaccines' availability. Outcomes: point prevalence of acute infection through saliva PCR (polymerase chain reaction) testing, point prevalence of past infection through serum antibodies against Covid-19, RD-STDC and prevalence of symptoms during the previous six months. Results. Prevalence of SARS-CoV-2 cases was 1.29-4.88%, on average, a quarter of participants pre-vaccination were seropositive; over half of participants with a RD-STDC had antibodies. The odds of having antibodies were 6-7 times more among workers with an RD-STDC. Conclusions. High antibody levels against Covid-19 in this study population reflects that coverage is high among workers in this industry. STDCs are a useful tool to track workplace epidemics.