Seroprevalence of SARS-CoV-2 antibodies in the general population of Oman: results from four successive nationwide sero-epidemiological surveys.

OBJECTIVE: To assess the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in Oman and longitudinal changes in antibody levels over time within the first 11 months of the coronavirus disease 2019 (COVID-19) pandemic. METHODS: This nationwide cross-sectional study was conducted as a four-cycle serosurvey using a multi-stage stratified sampling method from July to November 2020. A questionnaire was used and included demographics, history of acute respiratory infection and list of symptoms, COVID-19 contact, previous diagnosis or admission, travel history and risk factors. RESULTS: In total, 17,457 participants were surveyed. Thirty percent were female and 66.3% were Omani. There was a significant increase in seroprevalence throughout the study cycles, from 5.5% (4.8-6.2%) in Cycle 1 to 22% (19.6-24.6%) in Cycle 4. There was no difference in seroprevalence between genders, but significant differences were found between age groups. There was a transition of seroprevalence from being higher in non-Omanis than Omanis in Cycle 1 [9.1% (7.6-10.9%) vs 3.2% (2.6-3.9%)] to being higher in Omanis than non-Omanis in Cycle 4 [24.3% (21.0-27.9%) vs 16.8% (14.9-18.9%)]. There was remarkable variation in the seroprevalence of SARS-CoV-2 according to governorate. Close contacts of people with COVID-19 had a 96% higher risk of having the disease [adjusted odds ratio (AOR) 1.96, 95% confidence intervals (CI) 1.64-2.34]. Labourers had 58% higher risk of infection compared with office workers (AOR 1.58, 95% CI 1.04-2.35). CONCLUSION: This study showed a wide variation in the spread of SARS-CoV-2 across governorates in Oman, with higher estimated seroprevalence in migrants in the first two cycles. Prevalence estimates remain low and are insufficient to provide herd immunity.

The first clusters of Middle East respiratory syndrome coronavirus in Oman: Time to act.

INTRODUCTION: Middle East respiratory syndrome coronavirus (MERS-CoV), is an emerging infectious disease of growing global importance. This review describes the latest MERS-CoV clusters and the first cases of nosocomial transmission within health care facilities in Oman. We have highlighted lessons learned and proposed steps to prevent healthcare-associated infections. METHODS: A descriptive analysis of MERS-CoV cases was conducted between January 23 and February 16, 2019. The data from officials and other published sources used. RESULTS: Thirteen laboratory-confirmed cases of MERS-CoV were reported from three simultaneous clusters from two governorates without an epidemiological link between the clusters. Two clusters were reported from North Al Batinah Governorate, with nine cases (69%) and 1 cluster from South Ash Sharqiyah Governorate with four cases (31%). In total, four deaths were reported (case fatality rate 31%). Four cases (31%) reported were household contacts from the first cluster, 3 (23%) were nosocomial transmission in health care facilities (two for first and one from the second cluster) and 7 (54%) were community-acquired cases. CONCLUSIONS: The first local clusters of MERS-CoV reported with evidence suggestive of healthcare and household-associated transmission. Early diagnosis and strict implementation of infection control measures remain fundamental in preventing and managing MERS-CoV infection.