SARS-CoV-2 seroprevalence on the north coast of Peru: A cross-sectional study after the first wave

Peru had the second-highest number of COVID-19 cases in Latin America. After the first wave, Peru registered more than 900,000 cases of COVID-19 and more than 36,000 confirmed deaths from the disease. Tumbes, a border area with poor sanitation and not enough water, had the fifth highest death rate. The cross-sectional analytic study aimed: a) to assess seroprevalence of COVID-19 after the first wave; b) to assess sociodemographic determinants and symptoms associated with a positive COVID-19 antibody lateral flow test.

We performed this study between November 11th and November 30th, 2020, in an informal settlement in Tumbes. Individuals older than two years were invited to participate in a systematic random sample from one in every four households. Finger-prick blood samples were collected, and a census and symptom survey were applied. Within the chosen house, one adult over 18 years of age was chosen for a PCR-RT molecular test. Overall seroprevalence was 25.59%, adjusted seroprevalence was 24.82% (95%CI 22.49-27.25). Women had higher adjusted seroprevalence (28.03% vs 21.11%; 95% CI 24.83-31.41, p = 0.002). Symptoms as fever (PR 1.89: 95% CI 1.44-2.48, p<0.001), general discomfort (PR 1.67; 95% CI 1.23-2.26, p = 0.001), cough (PR 2.0; 95% CI 1.60-2.50, p<0.001), nasal congestion (PR 1.46; 95% CI 1.03-2.09, p = 0.036), respiratory distress (PR 1.64; 95% CI 1.04-2.56, p = 0.031), headache (PR 1.54; 95% CI 1.09-2.17, p = 0.014), anosmia (PR 1.78; 95% CI 1.01-3.14, p = 0.046) and ageusia (PR 2.31; 95% CI 1.48-3.61, p<0.001) were associated with a positive covid-19 antibody lateral flow test.

The COVID-19 transmission and distribution were highlighted by this cross-sectional study. The data will help the Ministry of Health improve its monitoring, surveillance, and monitoring of respiratory community sequelae in the future.