International Journal of Infectious Diseases (Nov 2021)

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

  • Seif Salem Al-Abri,
  • Adil Al-Wahaibi,
  • Hanan Al-Kindi,
  • Padmamohan J Kurup,
  • Ali Al-Maqbali,
  • Zayid Al-Mayahi,
  • Mohammed Hamed Al-Tobi,
  • Salim Habbash Al-Katheri,
  • Sultan Albusaidi,
  • Mahmood Humaid Al-Sukaiti,
  • Ahmed Yar Mohammed Al Balushi,
  • Iyad Omer Abdelgadir,
  • Nawal Al-Shehi,
  • Essam Morkos,
  • Amal Al-Maani,
  • Bader Al-Rawahi,
  • Fatma Alyaquobi,
  • Abdullah Alqayoudhi,
  • Khalid Al-Harthy,
  • Sulien Al-Khalili,
  • Azza Al-Rashdi,
  • Intisar Al-Shukri,
  • Thamra S. Al Ghafri,
  • Fatma Al-Hashmi,
  • Saeed Mussalam Al Jassasi,
  • Nasser Alshaqsi,
  • Nilanjan Mitra,
  • Humaid Suhail Al Aamry,
  • Parag Shah,
  • Hanan Hassan Al Marbouai,
  • Amany Hamed Al Araimi,
  • Ismail Mohammed Kair,
  • Asim Mohammed Al Manji,
  • Ahmed Said Almallak,
  • Fatma Khamis Al Alawi,
  • Vidyanand Vaidya,
  • Muhammad Muqeetullah,
  • Hanan Alrashdi,
  • Saud Said Nassir Al Jamoudi,
  • Asila Alshaqsi,
  • Abdullah Al Sharji,
  • Hamida Al Shukeiri,
  • Badr Al-Abri,
  • Sulaiman Al-Rawahi,
  • Said H. Al-Lamki,
  • Abdulla Al-Manji,
  • Amina Al-Jardani

Journal volume & issue
Vol. 112
pp. 269 – 277

Abstract

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ABSTRACT: 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.

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