Mutrah was the first district in Oman to experience COVID-19 community outbreak with 5.2% of population affected since the introduction of the disease on 23rd February until November 30th, 2020. A significantly higher population proportion might be infected and unreported. Estimation of community prevalence is important for public health decision making. Aim: To estimate the seroprevalence of IgG antibodies to SARS-CoV-2 and to describe associated epidemiological factors in Mutrah Wilayat.
Methodology
We conducted as serial cross-sectional, community-based sero-surveys in Muttrah between July 2020 and November 2020. Using active mobile numbers as sampling frame. We estimated a sample size of 384 and selected randomly from a list of active mobile phones in the area. We included consenting persons aged ≥ 6 years and asymptomatic in past 14 days at recruitment.
Results
16.8% (95% Cl: 13.9%-19.8%) of Muttrah district populations aged form 6 years and above were seropositive. Out of 613 participants, positivity rate was highest among 19-39 years (20.1%), males (16.9%), Bangladeshis (37.5%), shared accommodation (24.5%), less than 500 OMR income (21.9%), and 3 or more persons per room (31.3%). Out of 103 seropositive, only 21.5% were previously diagnosed positive COVID-19 and 9.7% had symptoms related COVID-19.
Conclusion
The real number of cases might be far higher than the reported during the epidemic in Muttrah until end of November. Asymptomatic patients, lower socioeconomic status and shared accommodations increased the transmission of the virus. The low estimated seroprevalence might indicates higher risk of second wave as many people are still susceptible to infection.