Covid-19 Serosurveillance. The map and the territory

The spread of the COVID-19 epidemic is unprecedented. Community data on COVID-19 are urgently needed to understand the extent, dynamics of transmission, sociodemographic and environmental variables associated. Seroprevalence studies allow knowing the frequency and distribution of the infection, regardless of the appearance of symptoms, as well as the evolution of the Serosurveillance by means of successive surveys. But serological tests for COVID-19 are characterized by a high risk of bias and heterogeneity; estimates of sensitivity and specificity are unreliable and had limited generalizability to populations. Tests with low specificity give more false positives than true positives in low prevalence settings, resulting in unacceptably low positive predictive values. Furthermore, differences in study methodology, viral load, clinical severity, intrinsic health of the study population, and several other potential confounders likely explain the variability between populations. The distribution of seroprevalence is very uneven geographically. Although it seems evident that in general seroprevalence is not high (from 5% or less to a maximum that could be around 20%). Group immunity, with exceptions, seems to be far away. The population is still susceptible to infection, and antibodies can decline quite rapidly. Periodic survey rounds should continue to monitor trends. Serosurveys are an indicator of a much broader response to infection that can lead to immunity; furthermore, they should serve to help develop and implement social measures on the living conditions to avoid the development of infections. In short, we began to have “maps” but we still do not know the “territory.”

Keywords: COVID-19; SARS-CoV-2; Seroprevalence; Surveillance; Epidemiology; Public Health Practice.

Coming Soon...

Coming Soon...