Background Monitoring changes of seroprevalence over time is important at the beginning and during of COVID-19 outbreak to anticipate its dynamics and plan an adequate public health response. Methods We conducted a repeated cross-sectional investigation among asymptomatic outpatient subjects and covered 0.1% of total population of Northern Serbia (Autonomous Province of Vojvodina). Each participant was tested for anti-SARS-CoV-2 antibodies using an immunochromatographic qualitative test (point-of-care rapid test). In the last round of survey IgG antibodies targeting the S1 subunit of the spike protein and the nucleocapsid protein of SARS-CoV-2 virus were assessed. Results During the four rounds of survey (between the end of April and the end of September), anti-SARS-CoV-2 seropositivities based on immunochromatographic test results were 2.60% (95% CI 1.80–3.63), 3.93% (95% CI 2.85–5.28), 6.11% (95% CI 4.72–7.77) and 14.60% (95% 12.51–16.89), respectively. After adjusting with results obtained from the Line immunoassay test, the estimated overall seroprevalence increased to 16.67% (95% CI 14.45–19.08) corresponding to 322,033 infections in total by the end of September 2020 in Vojvodina’s population. Throughout the course of the study, for every RT-PCR confirmed case of COVID-19, there were 39–87 additional infections in Vojvodina. No significant difference (p>0.05) in SARS-CoV-2 seropositivity regarding gender and between age subgroups was observed over the course of the survey. Conclusions The population prevalence of SARS-CoV-2 antibodies implies much more widespread infection in Vojvodina than indicated by the number of confirmed cases. However, our results suggest that the population of Vojvodina has not reached a desirable level of protection from SARS-CoV-2 virus by the end of September 2020.
【초록키워드】 COVID-19, public health, SARS-CoV-2, cross-sectional, Seroprevalence, Infection, Gender, SARS-CoV-2 virus, RT-PCR, anti-SARS-CoV-2, Spike protein, nucleocapsid protein, immunoassay, point-of-care, anti-SARS-CoV-2 antibodies, SARS-CoV-2 antibodies, IgG antibody, SARS-CoV-2 antibody, Asymptomatic, COVID-19 outbreak, Rapid test, anti-SARS-CoV-2 antibody, IgG antibodies, Seropositivity, age, monitoring, change, immunochromatographic, S1 subunit, test results, subgroup, qualitative test, rapid test), significant difference, 95% CI, no significant difference, subject, confirmed cases, total population, population prevalence, immunochromatographic test, repeated, widespread, LINE, Course, Result, the S1 subunit, indicated, conducted, the spike protein, reached, was tested, were assessed, 【제목키워드】 antibody,