COVID-19 epidemic monitoring after non-pharmaceutical interventions: The use of time-varying reproduction number in a country with a large migrant population

Adil Al Wahaibi*, Abdullah Al Manji, Amal Al Maani, Bader Al Rawahi, Khalid Al Harthy, Fatma Alyaquobi, Amina Al-Jardani, Eskild Petersen, Seif Al Abri

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


Background: COVID-19’s emergence carries with it many uncertainties and challenges, including strategies to manage the epidemic. Oman has implemented non-pharmaceutical interventions (NPIs) to mitigate the impact of COVID-19. However, responses to NPIs may be different across different populations within a country with a large number of migrants, such as Oman. This study investigated the different responses to NPIs, and assessed the use of the time-varying reproduction number (Rt) to monitor them. Methods: Polymerase chain reaction (PCR) laboratory-confirmed COVID-19 data for Oman, from February 24 to June 3, 2020, were used alongside demographic and epidemiological information. Data were arranged into pairs of infector–infectee, and two main libraries of R software were used to estimate reproductive number (Rt). Rt was calculated for both Omanis and non-Omanis. Findings: A total of 13,538 cases were included, 44.9% of which were Omanis. Among all these cases we identified 2769 infector–infectee pairs for calculating Rt. There was a sharp drop in Rt from 3.7 (95% confidence interval [CI] 2.8–4.6) in mid-March to 1.4 (95% CI 1.2–1.7) in late March in response to NPIs. Rt then decreased further to 1.2 (95% CI 1.1–1.3) in late April after which it rose, corresponding to the easing of NPIs. Comparing the two groups, the response to major public health controls was more evident in Omanis in reducing Rt to 1.09 (95% CI 0.84–1.3) by the end of March. Interpretation: Use of real-time estimation of Rt allowed us to follow the effects of NPIs. The migrant population responded differently than the Omani population.

Original languageEnglish
Pages (from-to)466-472
Number of pages7
JournalInternational Journal of Infectious Diseases
Publication statusPublished - Oct 2020
Externally publishedYes


  • COVID-19 epidemiology
  • Public health intervention
  • Reproductive number

ASJC Scopus subject areas

  • Microbiology (medical)
  • Infectious Diseases

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