Importance of Tuberculosis Screening of Resident Visa Applicants in Low TB Incidence Settings: Experience from Oman.

INTRODUCTION: For Oman, a country targeting tuberculosis (TB) elimination, TB among expatriates is a major challenge. Thus, screening for active TB using chest X-ray was made mandatory for expatriates' residency renewals. OBJECTIVE: To estimate the incidence of bacteriologically confirmed TB and assess impact of chest X-ray based TB screening among expatriates in Muscat Governorate. METHODS: Applicants for residency and renewals were mandated for chest X-ray-based TB screening in 2018. We collected data of screened subjects with radiological suspicion of TB who were subjected to further bacteriological evaluation. RESULTS: Of 501,290 applicants screened during the study period, 436 (0.09%) had X-ray findings suggestive of TB. Among the 436, TB was confirmed in 53 (12.2%; 95% CI 9.2-15.6), giving an overall prevalence of 10.6 (95% CI 8-13.9) per 100,000 applicants (number needed to be screened 9458). Among renewals, the point prevalence of TB was 10.5 per 100,000 expatriates screened (95% CI 6.9-14.04 per 100,000), with a mean follow-up period of 11.8 years. CONCLUSION: Our findings are consistent with the recommendation for utilization of chest X-ray as a preferred tool for active case finding in the setting of expatriate screening. Our findings are also suggestive of the need for latent TB screening and ruling out TB prior to latent TB treatment.

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.

Control of the 2018-2019 dengue fever outbreak in Oman: A country previously without local transmission.

BACKGROUND: In December 2018, routine surveillance identified an autochthonous outbreak of dengue fever in Muscat Governorate, Oman, a region previously free of dengue fever. METHODS: Routine surveillance confirmed locally acquired cases in the second week of December, leading to a rapid public health response including case management guidance and epidemiological investigations. The main activity was the vector survey using systematic sampling to assess extent of previously unreported Aedes aegypti presence followed by a campaign aimed to eliminate breeding sites of A. aegypti". RESULTS: During a 5-month period, 343 suspected cases were reported from Muscat Governorate with 122 from the outbreak affected area. Out of 207 probable cases eligible for laboratory testing as per guidelines issued, 59 cases were confirmed. The vector elimination campaign started on January 8, 2019 after a media advocacy using television and social media and concluded on January 23. By the end of campaign, the case load had decreased significantly in the affected area with no reports of locally acquired cases from adjoining areas of Muscat Governorate, indicating no further spread. CONCLUSIONS: Rapid notification and early community-wide, extensive vector control activities effectively contained the autochthonous dengue fever virus outbreak.

Knowledge, attitude and practice of travel medicine among primary care physicians in Oman: the need for intervention.

BACKGROUND: Oman is witnessing an increase in outbound and inbound travelers. AIMS: This study was undertaken to assess the current knowledge, attitude, and practice of travel medicine among primary care physicians (PCPs) working in the Muscat Governorate. METHODS: We conducted a cross-sectional survey of 108 primary healthcare physicians in primary healthcare institutions in the Muscat Governorate in December 2014 using a self-administered questionnaire. RESULTS: We had a response rate of 81%, 78% (n = 84) were females, 56.5% (n= 61) were Omani nationals. More than 50% (n= 54) of study participants had been in practice for more than 8 years. Sixty-eight (58.3%) reported having pre-travel consultations during the previous 1-month period and 86 (79.6%) had post-travel consultations. Most of the PCPs were aware of the issues that needed to be addressed in pre-travel consultation. CONCLUSIONS: This study showed that travel health is in an early stage of development in Oman and supports the need for the establishment of travel medicine services.

Epidemiology of Meningitis in Oman-Implications for Future Surveillance.

OBJECTIVES: This study aimed to understand the epidemiology of meningitis cases admitted to hospitals in Oman and to identify any changing microbial patterns from the introduction of the new vaccines. METHODS: A retrospective analysis of all cases of meningitis reported through a national surveillance system. Meningitis is a notifiable disease. RESULTS: Of a total of 581 cases of meningitis from the period between January 1, 2005 and December 31, 2013, 15% (88) were confirmed to be bacterial in origin and 7.2% (42/581) viral. In 50.9% (296) of patients with suspected pyogenic meningitis, no specific bacterial pathogen were identified, and in 26% of cases (151) a cerebrospinal fluid study could not be undertaken. Among 88 cases with confirmed bacterial pathogens the organisms identified were Streptococcus pneumoniae (65.9%), Neisseria meningitides (18.2%), Haemophilus influenzae (6.8%), and other organisms (9.1%). The peak incidence was in children <2 years of age (39.4%). It showed notable decline in H. influenzae cases as well as pneumococcal meningitis cases, possibly indicative of the successful immunization program. CONCLUSION: A drop in H. Influenzae and pneumococcal meningitis cases was possibly the effect of the introduction of vaccines. It shows the need for improving diagnostic accuracy, laboratory capacities, and quality of surveillance reporting.

The Effect of Obesity on Pregnancy and its Outcome in the Population of Oman, Seeb Province.

OBJECTIVES: The World Health Organization estimated that in 2011 worldwide 1.6 billion adults were overweight, and 400 million were obese. The obesity epidemic is a documented phenomenon and Oman is no exception. The aim of this study was to determine the effect of obesity on pregnancy and its prenatal and neonatal outcomes. METHODS: A prospective cohort study was carried out among pregnant Omani women attending antenatal clinics in their first trimester in the Seeb province of Muscat, Oman. RESULTS: A total of 700 pregnant women were enrolled in the study and were categorized according to their body mass index: 245 (35%) were normal weight, 217 (31%) were overweight, and 238 (34%) were obese. The relative risk (RR) of cesarean section among obese women compared to women of normal weight was 2.1 (95% confidence interval (CI) 1.2-3.2) and of overweight women was 1.4 (95% CI 0.9-2.3). The risk of elective cesarean section increased to 7.5 (95% CI 1.7-32.8) in obese women and was statistically significant in the obese group. In this study, 100 women (15.7%) developed gestational diabetes (11.8% of normal weight women, 17.8% of overweight women, and 17.9% of obese women). Miscarriages were more common among obese women 11.9% (n = 27) compared to the normal weight and overweight groups (6.7% and 9.4%, respectively). There was a weak yet statistically significant correlation between birth weight and body mass index. The risk of macrosomia was significantly higher in obese women compared to normal weight women. To evaluate the sensitivity of the oral glucose challenge test (OGCT), the oral glucose tolerance test (OGTT) was measured in 203 participants (29%) who had a normal OGCT result. It was found that 14.5% of overweight women and 13.5% of normal weight women had an abnormal OGTT result even when their OGCT result was normal. CONCLUSIONS: Obesity is associated with an increased risk of cesarean section (especially elective cesarean), gestational hypertension, macrosomia, and miscarriage. It also increases the risk of gestational diabetes.

The epidemiology and outcomes of infective endocarditis in a tertiary care hospital in Oman.

OBJECTIVES: We undertook this study to describe the epidemiological and clinical features of infective endocarditis (IE) and to study the complications and management of IE in a tertiary care hospital in Oman. METHODS: This is a retrospective study of 58 adult patients (>13 years of age) admitted to the Royal Hospital with IE from June 2006 to June 2011. RESULTS: Of the 58 patients, 40 (69%) were males, and 18 (31%) were females (ratio 2.2). The median age was 43.6 years (range: 14-85). Forty-eight cases (82.7%) had native valves, nine patients (15.6%) had prosthetic valves, and one case (1.7%) had a pacemaker. The most commonly involved valves were mitral (33, 56.9%) and aortic (23, 39.7%). The blood cultures were positive in 47 (81%) patients, and the most commonly isolated organisms were Streptococci spp., which were found in 20 (34.5%) patients, and Staphylococci spp., which were found in 19 (32.8%) patients. The complication rate was 21%. A total of 15 (25.9%) patients underwent surgical intervention, and the in-hospital mortality rate was 27.6%. CONCLUSIONS: Native-valve IE is the predominant type of endocarditis and is more of an acute disease. The prevalence of Staphylococci spp. IE is similar to that of Streptococci spp. IE, and its associated mortality remains high.

Management of Infants and Children who are Contacts of Contagious Tuberculous Patients.

Contact investigation and management form the key for tuberculosis (TB) control in countries with a low tuberculosis incidence. Oman, with a low TB incidence, has implemented contact investigation and management as one important strategy to control TB. However there is a lack of clear guidelines for the investigation and treatment of contacts, especially with regard to children who are contacts of TB cases. The failure to manage children in contact with infectious TB cases indicates a missed opportunity to prevent TB disease in a population which is prone to progress rapidly to severe and complicated illness. This article attempts to provide a concise and practical approach for managing infants and children who are in contact with TB patients. Essential steps in a variety of possible scenarios are briefly discussed.

A hospital acquired outbreak of Bacillus cereus gastroenteritis, Oman.

OBJECTIVES: To investigate the course of a hospital acquired outbreak of Bacillus cereus gastroenteritis outbreak, and the interventions that were taken to prevent such an outbreak from occurring again. METHODS: On May 3-5 2008, 58 cases of gastroenteritis were reported among patients and their attendants in a referral hospital in Oman. All affected had eaten meals served by the hospital kitchen the previous day. An outbreak investigation team conducted active surveillance and interviewed people about symptoms and food consumed on the preceding day in the hospital. Food samples from the kitchen and faecal samples from the kitchen staff and those affected were cultured. An environmental audit of the kitchen was conducted. RESULTS: The majority of the 58 persons affected by the outbreak were adult females, predominantly attendants of patients. 90% had diarrhoea and 10% had vomiting, usually mild. All those affected were managed symptomatically except for two patient attendants who required intravenous rehydration. The meal exposure histories implicated at least one meal from the kitchen. Many violations of basic food hygiene standards were observed in the kitchen. Toxin producing B. cereus was isolated from faeces of 3/12 (25%) patients and 19/25 (76%) of food handlers, and 35/61 (57%) of food samples from the kitchen. CONCLUSION: This is the first report of a nosocomial outbreak of foodborne B. cereus infection from this region. The importance of appropriate epidemiological and microbiological investigation and public relations management is emphasized, in addition to the need for continuing training of food handlers and rigorous enforcement of food hygiene regulations.

Fractional doses of inactivated poliovirus vaccine in Oman.

BACKGROUND: We conducted a clinical trial of fractional doses of inactivated poliovirus vaccine administered to infants in Oman, in order to evaluate strategies for making the vaccine affordable for use in developing countries. METHODS: We compared fractional doses of inactivated poliovirus vaccine (0.1 ml, representing one fifth of a full dose) given intradermally with the use of a needle-free jet injector device, with full doses of vaccine given intramuscularly, with respect to immunogenicity and reactogenicity. Infants were randomly assigned at birth to receive either a fractional dose or a full dose of inactivated poliovirus vaccine at 2, 4, and 6 months. We also administered a challenge dose of monovalent type 1 oral poliovirus vaccine at 7 months and collected stool samples before and 7 days after administration of the challenge dose. RESULTS: A total of 400 infants were randomized, of whom 373 (93.2%) fulfilled the study requirements. No significant baseline differences between the groups were detected. Thirty days after completion of the three-dose schedule, the rates of seroconversion to types 1, 2, and 3 poliovirus were 97.3%, 95.7%, and 97.9%, respectively, in the fractional-dose group, as compared with 100% seroconversion to all serotypes in the full-dose group (P=0.01 for the comparison with respect to type 2 poliovirus; results with respect to types 1 and 3 poliovirus were not significant). The median titers were significantly lower in the fractional-dose group than in the full-dose group (P<0.001 for all three poliovirus serotypes). At 7 months, 74.8% of the infants in the fractional-dose group and 63.1% of those in full-dose group excreted type 1 poliovirus (P=0.03). Between birth and 7 months, 42 hospitalizations were reported, all related to infectious causes, anemia, or falls, with no significant difference between vaccination groups. CONCLUSIONS: These data show that fractional doses of inactivated poliovirus vaccine administered intradermally at 2, 4, and 6 months, as compared with full doses of inactivated poliovirus vaccine given intramuscularly on the same schedule, induce similar levels of seroconversion but significantly lower titers. (Current Controlled Trials number, ISRCTN17418767.)

Low birth weight as a determinant of protein energy malnutrition in "0-5 years" Omani children of South Batinah region, Oman.

OBJECTIVE: To determine the risk factors of protein energy malnourishment (PEM) among 0-5 year old children in South Batinah region, Oman. METHODS: at are maintained at the primary health institutions of the study area. This case control study was conducted between March 2003 and May 2003. The information of their birth weight, birth interval, birth order, twin pregnancy, history of underweight and death among siblings, presence of congenital anomalies, breast feeding status, social problem and other ail RESULTS: The median birth order among PEM cases was significantly higher compared to the children without PEM (Mann Whitney test; p=0.029). Using multivariate logistic regression technique, we found that low birth weight (odds ratio [OR] 2.32; confidence intervals [CI] 95% 1.61-3.33), higher birth order (OR 1.04; CI 95% 1.01-1.08) and sibling with history of under weight [OR 1.79 (CI 95% 0.97- 3.28)] were significant predictors of PEM. CONCLUSION: It is possible to identify children with high-risk of PEM using information on birth weight, birth order and history of PEM in sibling. This non-anthropometric method can be used as an additional tool for monitoring growth of children and formulate preventive interventions.