Results
The serosurvey was conducted from 2–13 August 2021. Capillary blood samples were obtained from 438 participants; 72 samples was insufficient to conduct the Platelia ELISA, the last test conducted. Table 1 shows the comparisons between the tests. Table 2 shows the sensitivity, specificity, PPV and NPV, LR+ and LR-, and kappa coefficient of agreement of the rapid test and Platelia ELISA against the Wantai ELISA. The Wantai ELISA showed greater percentage positive results (82.6%) compared with the rapid test (51.8%) and the Platelia ELISA (69.7%). Of the rapid test results, 23 were IgM positive, 151 were IgG positive; 53 were both IgM and IgG positive. Only 30 (6.8%) participants reported one or more COVID-19 vaccine doses up to five months before the study, with no difference in percentage positive results or kappa values of agreement between the total and non-vaccinated population.