Screening for latent tuberculosis in migrants-status quo and future challenges.

OBJECTIVES: To review the evidence that migrants from tuberculosis (TB) high-incidence countries migrating to TB low-incidence countries significantly contribute to active TB cases in the counties of destination, primarily through reactivation of latent TB. METHODS: This is a narrative review. The different screening programs in the countries of destination are reviewed either based on screening and preventive treatment of latent TB pre or more commonly - post arrival. RESULTS: Screening can be performed using interferon-gamma release assays (IGRA) or tuberculin skin tests (TST). Preventive treatment of latent TB is using either monotherapy with isoniazid, or in combination with rifampicin or rifapentine. We discuss the ethical issues of preventive treatment in asymptomatic individuals and how these are addressed in different screening programs. CONCLUSION: Screening migrants from TB high endemic countries to TB low endemic countries is beneficial. There is a lack of standardization and agreement on screening protocols, follow up and treatment.

Hypervirulent Capsular Serotypes K1 and K2 Klebsiella pneumoniae Strains Demonstrate Resistance to Serum Bactericidal Activity and Galleria mellonella Lethality.

Hypervirulent Klebsiella pneumoniae (hvKp) is a variant that has been increasingly linked to severe, life-threatening infections including pyogenic liver abscess and bloodstream infections. HvKps belonging to the capsular serotypes K1 and K2 have been reported worldwide, however, very scarce studies are available on their genomics and virulence. In the current study, we report four hypermucoviscous extended-spectrum ß-lactamase-producing hvKp clinical strains of capsular serotype K1 and K2 isolated from pus and urine of critically ill patients in tertiary care hospitals in Oman. These strains belong to diverse sequence types (STs), namely ST-23(K1), ST-231(K2), ST-881(K2), and ST-14(K2). To study their virulence, a Galleria mellonella model and resistance to human serum killing were used. The G. mellonella model revealed that the K1/ST-23 isolate was the most virulent, as 50% of the larvae died in the first day, followed by isolate K2/ST-231 and K2/ST-14, for which 75% and 50% of the larvae died in the second day, respectively. Resistance to human serum killing showed there was complete inhibition of bacterial growth of all four isolates by the end of the first hour and up to the third hour. Whole genome sequencing (WGS) revealed that hvKp strains display a unique genetic arrangement of k-loci. Whole-genome single-nucleotide polymorphism-based phylogenetic analysis revealed that these hvKp isolates were phylogenetically distinct, belonging to diverse clades, and belonged to different STs in comparison to global isolates. For ST-23(K1), ST-231(K2), ST-881(K2), and ST-14(K2), there was a gradual decrease in the number of colonies up to the second to third hour, which indicates neutralization of bacterial cells by the serum components. However, this was followed by a sudden increase of bacterial growth, indicating possible resistance of bacteria against human serum bactericidal activity. This is the first report from Oman detailing the WGS of hvKp clinical isolates and assessing their resistance and virulence genomics, which reinforce our understanding of their epidemiology and dissemination in clinical settings.

Time trend of respiratory viruses before and during the COVID-19 pandemic in severe acute respiratory virus infection in the Sultanate of Oman between 2017 and 2022.

Introduction: Severe acute respiratory illness (SARI) is a potentially lethal condition, necessitating thorough medical care. COVID-19 underscored the SARI threat, but other high-risk pathogens require monitoring alongside SARS-CoV-2. Oman instituted a comprehensive testing system to gauge the prevalence of these pathogens between 2017 and 2021, aiding resource allocation and public health responses to potential respiratory pathogen outbreaks. Methods: Samples from SARI cases admitted to ICU were tested for pathogens using the Fast-Track Diagnostic (FTD) molecular assay, a respiratory virus panel (RVP) that tests for 21 pathogens, including 20 viruses, by qPCR. Results: Between 2017 and 2022, ~30 000 samples were analysed using the RVP panel. Among SARI patients, 8%-42% tested positive for respiratory pathogens, with 4% showing multiple infectious agents, especially in children under 10. A drop in positivity during 2020-2021 can be attributed to SARS-CoV-2 control measures, followed by a rebound in infections in early 2022. Discussion: The COVID-19 pandemic heightened awareness of respiratory pathogens' spread without adequate control measures. Influenza A/B, human rhinoviruses and respiratory syncytial virus constituted over 50% of severe acute respiratory illness cases in Oman over the past 5 years. During the pandemic, the incidence of these infections significantly declined, demonstrating the efficacy of COVID-19 prevention measures in reducing spread of other pathogens.

Recurrent Infective Endocarditis in an Adolescent due to Streptococcus agalactiae: A Rare Presentation of a Common Pathogen.

Streptococcus agalactiae is known to cause invasive infections in risk groups such as pregnant women, newborns, and immunosuppressed patients but it is uncommon in older children. We describe a case of recurrent infective endocarditis due to S. agalactiae in an 11-year-old boy with Loeys-Dietz syndrome who was successfully treated with long-term antimicrobial therapy for one year.

Mycobacterium tuberculosis epidemiology in Oman: whole-genome sequencing uncovers transmission pathways.

Tuberculosis (TB) originating from expatriates that hail from high TB-burden countries is hypothesized to play a role in continued TB transmission in Oman. Here, we used whole-genome sequencing (WGS) to assess national TB transmission dynamics. The annual incidence per 100,000 population per year was calculated for nationals and expatriates. A convenience sample of Mycobacterium tuberculosis (MTB) isolates from 2018 to 2019 was sequenced and analyzed with publicly available TB sequences from Bangladesh, Tanzania, the Philippines, India, and Pakistan. Relatedness was assessed by generating core-genome single nucleotide polymorphism (SNP) distances. The incidence of TB was five cases per 100,000 persons in 2018 and seven cases per 100,000 persons in 2020 (R2 = 0.34, P = 0.60). Incidence among nationals was 3.9 per 100,000 persons in 2018 and 3.5 per 100,000 persons in 2020 (R2 = 0.20, P = 0.70), and incidence among expatriates was 7.2 per 100,000 persons in 2018 and 12.7 per 100,000 persons in 2020 (R2 = 0.74, P = 0.34). Sixty-eight local MTB isolates were sequenced and analyzed with 393 global isolates. Isolates belonged to nine distinct spoligotypes. Two isolates, originating from an expatriate and an Omani national, were grouped into a WGS-based cluster (SNP distance < 12), which was corroborated by an epidemiological investigation. Relatedness of local and global isolates (SNP distance < 100) was also seen. The relatedness between MTB strains in Oman and those in expatriate countries of origin can aid inform TB control policy. Our results provide evidence that WGS can complement epidemiological analysis to achieve the End TB strategy goal in Oman. IMPORTANCE Tuberculosis (TB) incidence in Oman remains above national program control targets. TB transmission originating from expatriates from high TB-burden countries has been hypothesized to play a role. We used whole-genome sequencing (WGS) to assess TB transmission dynamics between expatriates and Omani nationals to inform TB control efforts. Available Mycobacterium tuberculosis isolates from 2018 to 2019 underwent WGS and analysis with publicly available TB sequences from Bangladesh, the Philippines, India, and Pakistan to assess for genetic relatedness. Our analysis revealed evidence of previously unrecognized transmission between an expatriate and an Omani national, which was corroborated by epidemiological investigation. Analysis of local and global isolates revealed evidence of distant relatedness between local and global isolates. Our results provide evidence that WGS can complement classic public health surveillance to inform targeted interventions to achieve the End TB strategy goal in Oman.

The Seroprevalence of Hepatitis C Virus (HCV) in Hemodialysis Patients in Oman: A National Cross-Sectional Study.

BACKGROUND: HCV infection in hemodialysis units is a significant cause of morbidity and mortality. The risk of HCV infection among dialysis patients is higher compared to the general population due to high potential blood exposures in hemodialysis settings. This study aims to assess the national HCV seroprevalence in selected dialysis units and to determine the risk factors for acquiring HCV infection. METHODS: This cross-sectional study was conducted from 1 January to 31 March 2021. A total of 734 patients from 11 hemodialysis centers in Oman were included. Samples were tested simultaneously for HCV antibodies and HCV RNA. HCV genotyping was determined in all viremic patients. Demographic and hemodialysis center related data were gathered and their association with the positive HCV serology were explored using univariate and multivariate logistic regression analysis. RESULTS: Out of 800 patients selected from 11 dialysis units for the study, 734 patients (91.8%) were included. The overall seroprevalence of HCV infection among hemodialysis patients was 5.6%. (41/734). HCV RNA was detected in 31.7% (13/41) of seropositive hemodialysis patients. The most common genotype was subtype 1a, followed by subtype 3. Variables associated with high HCV prevalence were family history of HCV and duration of dialysis. CONCLUSION: The prevalence of infection within hemodialysis patients in Oman has significantly decreased but remained higher than the general population. Continuous monitoring and follow-up, including periodic serosurvey and linkage to care and treatment are recommended. Additionally, practice audits are recommended for identifying gaps and ensuring sustainability of best practices and further improvement.

Genomic and geospatial epidemiology of Mycobacterium tuberculosis in Oman: first national insight using whole genome sequencing.

OBJECTIVES: Mycobacterium tuberculosis (MTB) is a global public health issue. Although Oman reduced the burden of tuberculosis (TB) by 85% in under 25 years, the annual incidence rate remains stagnant. Whole genome sequencing (WGS) is used to investigate the transmission dynamics of MTB complex. This study aimed to resolve traditional genotype clusters and exploring the geospatial distribution to understand the epidemiology of TB in Oman. METHODS: Confirmed cases with spoligotyping clusters were randomly selected. WGS of 70 isolates were selected for final analysis. Correlation of epidemiological and geospatial data was conducted. RESULTS: A total of 233 cases were registered in 2021; 169 had confirmed growth, with an incidence rate of 5.2/100,000 population for 2021. A total of 70 genomes were analyzed, and five large clusters and three medium clusters were identified. The lineages L1, L2, L3, and L4 and several sublineages belonging to the Indo-Oceanic family and East African Indian family were identified as predominant in Oman. There were no multidrug-resistant cases identified. CONCLUSION: There is a considerable genetic variation among the strains in Oman. This predominance could be linked with the high percentage of non-national population, which represents different countries and frequent traveling to high TB burden countries. WGS combined with geospatial investigations of MTB are required to better understand the disease transmission in Oman, which will support TB elimination efforts.

External quality assessment of laboratory performance in bacteriology in the Eastern Mediterranean Region, 2011-2019.

Background: Since 2007, national public health laboratories in the WHO Eastern Mediterranean Region (EMR) have participated in a regional external quality assessment scheme in bacteriology to improve testing proficiency. Aims: To assess laboratory performance in bacteriology in the EMR between 2011 and 2019 using the regional external quality assessment scheme. Methods: We analysed the accuracy of participant-reported data in bacterial identification, Gram stain microscopy, and antimicrobial susceptibility testing. For each category, we assessed the performance over time, the performance on multiple organisms, and whether a laboratory repeatedly failed to attain satisfactory results. Results: Between 2011 and 2019, 70% of laboratories achieved satisfactory performance for bacterial identification and antimicrobial susceptibility testing, and 85% performed satisfactory Gram stain microscopy. Testing did not improve on multiple organisms and results were consistently low for some pathogens and test categories. Twenty-nine percent of laboratories underperformed throughout the study period. Conclusion: The unchanged performance over time and underperformance of laboratories highlight the need for improvements in the regional external quality assessment scheme. Participating laboratories and WHO need to work more actively to strengthen the problem areas.

Genomic analysis of the emerging carbapenem-resistant Klebsiella pneumoniae sequence type 11 harbouring Klebsiella pneumoniae carbapenemase (KPC) in Oman.

BACKGROUND AND OBJECTIVE: The presence of carbapenemase enzymes among Enterobacterales is the main mechanism to reduce susceptibility to a wide range of antibiotics. Carbapenemase enzymes such as the Klebsiella pneumoniae carbapenemase (KPC) hydrolyse beta-lactam antibiotics group, which includes carbapenem, leads to fewer treatment options. We aim to describe the first report of carbapenem-resistant K. pneumoniae (CRKP) sequence type (ST) 11 harbouring KPC in Oman. MATERIAL AND METHODS: Five confirmed CRKP isolates were isolated from clinical samples during the period of January 2019 till December 2019. Strains were genotyped by pulse field gel electrophoresis (PFGE) for genetic relatedness. Whole genome sequencing (WGS) was performed to observe relationships with global strains using multilocus sequence typing (MLST). Antimicrobial genes, capsular loci-K-types, plasmids types and virulence genes were also identified using whole genome sequence data. RESULTS: All five CRKP were determined to have blaKPC-2 with or without blaOX-A48 and blaNDM-2. The molecular genotyping by PFGE showed 100% similarity among the five isolates. The MLST allelic profile analysis clonally clustered our strains with SL-258, CG-11 and ST11 mainly reported from South Asia. Further molecular characterization of the capsular K-locus and O-locus genes, revealed the strains to belong to KL-47 type and OL101 type respectively. The core genome typing suggests that our strains were clonally related to Chinese strains with less than five chromosomal nucleotides differences. CONCLUSION: Epidemiological and molecular analyses confirmed that these KPC-producing K. pneumoniae strains are from a single clone that caused multiple nosocomial infections in one health institution. This finding highlights the importance to sustain the surveillance and infection prevention efforts and to step up active screening to prevent the spread of nosocomial infection.

Drug resistant Mycobacterium tuberculosis in Oman: resistance-conferring mutations and lineage diversity.

Background: The Sultanate of Oman is country a low TB-incidence, with less than seven cases per 105 population detected in 2020. Recent years have witnessed a persistence in TB cases, with sustained incidence rate among expatriates and limited reduction among Omanis. This pattern suggests transmission from the migrant population. The present study examined the genetic profile and drug resistance-conferring mutations in Mycobacterium tuberculosis collected from Omanis and expatriates to recognise possible causes of disease transmission. Methods: We examined M. tuberculosis cultured positive samples, collected from Omanis (n = 1,344) and expatriates (n = 1,203) between 2009 and 2018. These isolates had a known in vitro susceptibility profile to first line anti-TB, Streptomycin (SM), Isoniazid (INH), Rifampicin (RIF), Ethambutol (EMB) and Pyrazinamide (PZA). The diversity of the isolates was assessed by spacer oligo-typing (spoligotyping). Drug resistance-conferring mutations resulted from full-length sequence of nine genes (katG, inhA, ahpc, rpoB, rpsL, rrs, embB, embC, pncA) and their phenotypic relationship were analysed. Results: In total, 341/2192 (13.4%), M. tuberculosis strains showed resistance to any drug, comprising mono-resistance (MR) (242, 71%), poly-resistance (PR) (40, 11.7%) and multi-drug resistance (MDR) (59, 17.3%). The overall rate of resistance among Omanis and expatriates was similar; however, MDR and PZAR were significantly higher among Omanis, while INHR was greater among expatriates. Mutations rpsL K43R and rpoB S450L were linked to Streptomycin (SMR) and Rifampicin resistance (RIFR) respectively. Whereas, katG S315T and inhA -C15T/G-17T were associated with Isoniazid resistance (INHR). The resistance patterns (mono-resistant, poly-resistant and MDR) and drug resistance-conferring mutations were found in different spoligo-lineages. rpsL K43R, katG S315T and rpoB S450L mutations were significantly higher in Beijing strains. Conclusions: Diverse drug resistant M. tuberculosis strains exist in Oman, with drug resistance-conferring mutations widespread in multiple spoligo-lineages, indicative of a large resistance reservoir. Beijing's M. tuberculosis lineage was associated with MDR, and multiple drug resistance-conferring mutations, favouring the hypothesis of migration as a possible source of resistant lineages in Oman.

Prevalence of Hepatitis B Infection Among Pregnant Women in Oman.

OBJECTIVE: The primary objective of our study was to estimate the prevalence of hepatitis B infection among pregnant women in Oman. The secondary objectives were to test for other hepatitis B virus (HBV) serological markers and to determine hepatitis B viral load. METHODS: In this cross-sectional study conducted from June 2019 to December 2020, we randomly selected 2210 Omani women who attended antenatal clinics across the country. Pregnant women were tested for HBV surface antigen (HBsAg) using a commercial enzyme immunoassay; those who tested positive were further analyzed for other HBV serological markers: HBV core total antibody (anti-HBc), HBV core antibody IgM (immunoglobulin M) (anti-HBc IgM), hepatitis B virus e antigen (HBeAg) and hepatitis B virus e antibody (anti-HBe). They were also tested for hepatitis B viral load. RESULTS: This study included 2210 women with a mean age of 39 years. Ninety-five percent of the women who were invited to participate consented and were included in the study. Thirty-three (1.49%) tested positive for HBsAg. All participants tested negative for HBeAg and anti-HBc IgM and positive for anti-HBc and anti-HBe, and 30 (90.9%) women had their hepatitis B viral load measured. Three (10.0%) had undetectable viral loads, 23 (76.7%) had low viral loads of < 2000 (IU/ml), 2 had moderate viral loads between 2000 and 200,000 (IU/ml) and one had a high viral load of 486,000 (IU/ml). CONCLUSION: Our study shows that the HBV prevalence in pregnant women is 1.49%, which is lower than what was reported earlier. Nevertheless, antenatal screening is still warranted, as there are vital interventions for the newborn and the mother.

Dynamics of Mycobacterium tuberculosis Lineages in Oman, 2009 to 2018.

Study aim. Effective Tuberculosis (TB) control measures in Oman have reduced the annual incidence of tuberculosis cases by 92% between 1981 and 2016. However, the current incidence remains above the program control target of <1 TB case per 100,000 population. This has been partly attributed to a high influx of migrants from countries with high TB burdens. The present study aimed to elucidate Mycobacterium tuberculosis infection dynamics among nationals and foreigners over a period of 10 years. Methods. The study examined TB cases reported between 2009 and 2018 and examined the spatial heterogeneity of TB cases and the distribution of M. tuberculosis genotypes defined by spoligotypes and MIRU-VNTR among Omanis and foreigners. Results. A total of 484 spoligoprofiles were detected among the examined isolates (n = 1295). These include 943 (72.8%) clustered and 352 (27.2%) unique isolates. Diverse M. tuberculosis lineages exist in all provinces in Oman, with most lineages shared between Omanis and foreigners. The most frequent spoligotypes were found to belong to EAI (318, 30.9%), CAS (310, 30.1%), T (154, 14.9%), and Beijing (88, 8.5%) lineages. However, the frequencies of these lineages differed between Omanis and foreigners. Of the clustered strains, 192 MTB isolates were further analysed via MIRU-VNTR. Each isolate exhibited a unique MIRU-VNTR profile, indicative of absence of ongoing transmission. Conclusions. TB incidence exhibits spatial heterogeneity across Oman, with high levels of diversity of M. tuberculosis lineages among Omanis and foreigners and sub-lineages shared between the two groups. However, MIRU-VNTR analysis ruled out ongoing transmission.

PulseNet International Survey on the Implementation of Whole Genome Sequencing in Low and Middle-Income Countries for Foodborne Disease Surveillance.

PulseNet International (PNI) is a global network of 88 countries who work together through their regional and national public health laboratories to track foodborne disease around the world. The vision of PNI is to implement globally standardized surveillance using whole genome sequencing (WGS) for real-time identification and subtyping of foodborne pathogens to strengthen preparedness and response and lower the burden of disease. Several countries in North America and Europe have experienced significant benefits in disease mitigation after implementing WGS. To broaden the routine use of WGS around the world, challenges and barriers must be overcome. We conducted this study to determine the challenges and barriers countries are encountering in their attempts to implement WGS and to identify how PNI can provide support to improve and become a better integrated system overall. A survey was designed with a set of qualitative questions to capture the status, challenges, barriers, and successes of countries in the implementation of WGS and was administered to laboratories in Africa, Asia-Pacific, Latin America and the Caribbean, and Middle East. One-third of respondents do not use WGS, and only 8% reported using WGS for routine, real-time surveillance. The main barriers for implementation of WGS were lack of funding, gaps in expertise, and training, especially for data analysis and interpretation. Features of an ideal system to facilitate implementation and global surveillance were identified as an all-in-one software that is free, accessible, standardized and validated. This survey highlights the minimal use of WGS for foodborne disease surveillance outside the United States, Canada, and Europe to date. Although funding remains a major barrier to WGS-based surveillance, critical gaps in expertise and availability of tools must be overcome. Opportunities to seek sustainable funding, provide training, and identify solutions for a globally standardized surveillance platform will accelerate implementation of WGS worldwide.

Burkholderia pseudomallei Septic Arthritis of the Knee Joint: Report of a Third Imported Case in Oman.

Melioidosis is a severe disease that can affect humans and animals. It is caused by Burkholderia pseudomallei, which is an environmental aerobic gram negative bacteria. Despite being endemic in Southeast Asia and Northern Australia, many cases have been reported from different regions, including the Middle East. This is the third imported case of B. pseudomallei from Oman in a 46-year-old Indian male with left knee septic arthritis in less than three weeks after arrival in Oman. He underwent open arthrotomy, and his synovial fluid culture grew a bacteria with dry, pink colonies that were oxidase positive, susceptible to amoxicillin-clavulanic, identified by API NE as B. pseudomallei, and confirmed by molecular tests. This single case report highlights the urgent need to increase molecular diagnostic capacity and improve public health surveillance while maintaining a one health tripartite approach.

Challenges and Opportunities for Public Health Service in Oman From the COVID-19 Pandemic: Learning Lessons for a Better Future.

Despite the apparent challenges inflicted by COVID-19 globally, the pandemic provided an opportunity to utilize and expand existing public health capacities for a more adaptive and resilient system during and after each wave of the disease. This paper provides a narrative review of Oman's public health response to the COVID-19 pandemic from January 2020 to July 2021, and the challenges it faced for a more rapid and efficient response. The review demonstrates that the three main pillars influencing the direction of the pandemic and aiding the control are Oman's unified governmental leadership, the move to expand the capacity of the health care system at all levels, and community partnership in all stages of the response including the COVID-19 vaccination campaign. The opportunities identified during response stages in the harmonization of the multisectoral response, streamlining communication channels, addressing vulnerable communities (dormitories, residences at border regions), and providing professional technical leadership provide an excellent precursor for expediting the transformation of Oman's health care system to one with a multisectoral holistic approach. Some of the major challenges faced are the shortage of the public health cadre, lack of a fully integrated digital platform for surveillance, and the scarcity of experts in risk communication and community engagement. A future health system where the center for diseases surveillance and control acts as a nucleus for multisectoral expertise and leadership, which includes community representatives, is crucial to attain optimum health. The destruction inflicted by this prolong COVID-19 pandemic at all levels of human life had valued the importance of investing on preventive and preparedness strategies.

Evaluation of Four Rapid Antigen Tests for Detection of SARS-CoV-2 virus.

OBJECTIVES: Considering the increasing, significant burden that coronavirus disease 2019 (COVID-19) imposes on the healthcare system, the need for simple, rapid, and affordable diagnostic tests to support the existing costly and demanding polymerase chain reaction (PCR) assay becomes required. This prospective diagnostic test accuracy study aims to evaluate the performance of four different COVID-19 rapid antigen tests compared to real-time reverse transcription PCR (rRT-PCR) between June and July 2020 to determine the feasibility of integrating these tests into the diagnostic algorithm in clinical settings. METHODS: Swabs were collected from 306 patients and analyzed using rRT-PCR and antigen tests from four different providers. RESULTS: The antigen tests' sensitivities were 65.8%, 69.8%, 64.0%, and 64.3% for the STANDARD™ Q COVID-19 Ag test, PCL COVID-19 Ag Rapid fluorescent immunoassay (FIA) test, BIOCREDIT COVID-19 Ag test, and Sofia SARS-CoV-2 antigen FIA test, respectively. Specificity was 94.1% for PCL COVID-19 Ag Rapid test and 100% for the other three assays. All assays showed a significant negative correlation between the reference rRT-PCR Ct values and Ag test results. Besides, sensitivities of the STANDARD™ Q COVID-19 Ag test, PCL COVID-19 Ag Rapid FIA test, and BIOCREDIT COVID-19 Ag test improved to ≥ 85% after exclusion of samples with PCR Ct values > 30. CONCLUSIONS: The high specificity of the rapid antigen tests and other parameters like simplicity, rapidity, and affordability suggest that antigen tests are likely to be helpful if integrated and interpreted appropriately in stepwise diagnostic algorithms. Given the low sensitivity of 64.0-69.8% of the antigen tests, we recommend that clinically relevant negative results undergo further testing Ag to confirm or exclude a COVID-19 diagnosis.

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.

The role of children and adolescents in the transmission of SARS-CoV-2 virus within family clusters: A large population study from Oman.

BACKGROUND: In Oman, many extended families tend to live in one household. Some families can include 20-30 individuals with the majority of them being children. This study investigates the role of children in spreading SARS-CoV-2 causing COVID-19 within family clusters in Oman. METHODS: This retrospective study includes data of 1026 SARS-CoV-2 positive children (≤18 years) collected from the national surveillance database for COVID-19 between 1 February 2020 and 30 May 2020. RESULTS: We included 1026 patients. Most, 842 were Omani (82%), 52% male, and 28.5% asymptomatic. Close to the half of symptomatic 419 (40%), patients presented with fever associated with other respiratory symptoms. Fifty pediatric patients were index cases who transmitted the virus to 107 patients in total (86 adults and 21 children) with a mode of 1. There is no statistical significance of all studied risk factors in the transmission of the SARS-CoV-2 virus including age, gender, and cycle threshold (CT) value. CONCLUSIONS: According to this study, children are not to be considered a significant driver of transmission of SARS-CoV-2 in Oman.

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.