The Impact of Mobility Restriction Strategies in the Control of the COVID-19 Pandemic: Modelling the Relation between COVID-19 Health and Community Mobility Data.

BACKGROUND: Non-pharmaceutical interventions (NPIs), particularly mobility restrictions, are mainstay measures for the COVID-19 pandemic worldwide. We evaluated the effects of Oman's mobility restriction strategies to highlight their efficacy in controlling the pandemic. METHODS: Accessible national data of daily admissions and deaths were collected from 1 April 2020 to 22 May 2021. Google Community Mobility Report (CMR) data were downloaded for the same period. Among six CMR categories, three were used and reduced to one index-the community mobility index (CMI). We used a generalised linear model with a negative binomial distribution combined with a non-linear distributed lag model to investigate the short-term effects of CMI on the number of admitted PCR-confirmed COVID-19 cases and deaths, controlling for public holidays, day of the week, and Eid/Ramadan days. RESULTS: We demonstrated the feasibility of using CMRs in the evaluation and monitoring of different NPIs, particularly those related to movement restriction. The best movement restriction strategy was a curfew from 7 p.m. to 5 a.m. (level 3 of CMI = 8), which had a total reduction of 35% (95% confidence interval (CI); 25-44%) in new COVID-19 admissions in the following two weeks, and a fatality reduction in the following four weeks by 52% (95% CI; 11-75%). CONCLUSION: Evening lockdown significantly affected the course of the pandemic in Oman which lines up with similar studies throughout the world.

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.

Epidemiological Characteristics of Pandemic Coronavirus Disease (COVID-19) in Oman.

OBJECTIVES: The aim of the current study was to describe COVID-19's epidemiological characteristics in Oman during the initial stages of the outbreak and compare findings with other countries' reports. METHODS: Data were drawn from a descriptive, records-based review of reported cases of COVID-19 collected through the national COVID-19 Surveillance System from February to April 2020. RESULTS: A total of 2,443 confirmed cases were reported during the study period. The overall first-time testing rate for this period was 851.7 per 100,000, the positivity rate was 53.1 (confidence intervals [CI]: 51.0-55.2) and the death rate was 0.32 (CI: 0.20-0.54) per 100,000 population, respectively. The overall national positive ratio was 5.7% and ranged from 2.2-7.1% across various governorates. Muscat Governorate had the highest positive ratio (12.5%). People in the 51-60 year old age group (RR = 1.97), males (RR = 1.24), non-Omanis (RR = 2.33) and those living in Muscat (RR = 2.14) emerged as categories with significant demographic risk for COVID-19 cases when compared to the national average. The mean age was 35.6 ± 13.4. Asymptomatic cases accounted for nearly 16%. CONCLUSION: The overall rate of COVID-19 cases and deaths were low in Oman compared to the rest of the world during the study period.

Effects of COVID-19 on mortality: A 5-year population-based study in Oman.

BACKGROUND: Mortality surveillance provides a crucial method for monitoring disease activity. Coronavirus disease 2019 (COVID-19) can cause excess mortality both directly and indirectly by increasing deaths from other diseases. The aim of this study was to investigate the effects of COVID-19 on mortality in Oman. METHODS: A cross-sectional retrospective analysis of mortality data from 1 January 2015 to 16 August 2020 was undertaken. Baseline mortality estimated using the Farrington flexible model and excess mortality were calculated for the pandemic period (16 March-16 August 2020) according to cause of death, place of death and age group. RESULTS: During the pandemic period, there was a 15% [95% confidence interval (CI) 14-17] increase in all-cause mortality from baseline. When classifying by cause, there was a 9% (95% CI 5-12) increase in deaths due to respiratory diseases, a 2% (95% CI 1-4) increase in deaths due to infectious diseases and a 9% (95% CI 8-11) increase in unclassified deaths. In terms of place of death, 12% (95% CI 11-14) of excess mortality occurred in hospitals and 7% (95% CI 5-8) occurred in homes during the pandemic period. Patients aged >60 years recorded a 15% (95% CI 13-16) increase in all-cause mortality during this period. CONCLUSION: The COVID-19 pandemic has resulted in a 15% increase in all-cause mortality in Oman, mainly as a result of deaths from COVID-19. However, unclassified deaths, deaths due to respiratory diseases and deaths due to infectious diseases have also increased, enforcing the need for a holistic approach and appropriate coordination of health services during such health crises.

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

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.