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.

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.

A second local dengue fever outbreak: A field experience from Muscat Governorate in Oman, 2022.

Background: Dengue fever is an infectious disease of global health concern. This study aimed to describe the epidemiology and field experience of a locally transmitted outbreak of dengue fever in Muscat Governorate, Oman from mid-March to mid-April 2022, and the multi-sectoral approach to control the outbreak. Methods: Data were collected from an electronic e-notification system, active surveillance and contact investigations. Results: Of 250 suspected and probable cases, 169 were confirmed as dengue fever with DENV-2 serotype. Of these, 108 (63.9%) were male and 94 (55.6%) were Omani. The mean age was 39 years (standard deviation 13 years). Fever was the most common symptom and occurred in 100% of cases. Haemorrhagic manifestations occurred in 10% (n=17) of cases. Hospitalization was required for 93 cases (55.1%). The field investigation included 3444 houses and other suspected sites. Breeding sites for Aedes aegypti were identified in 565 (18.5%) sites visited. Interventions to control the outbreak included environmental and entomological assessment of the affected houses and surrounding areas (400 m radius of each house). Conclusion: Outbreaks are expected to continue, with the possibility of severe cases due to antibody-dependent enhancement. More data are required to understand the genetics, geographical spread and behaviour of A. aegypti 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.

Retention in HIV care and factors associated with loss to follow-up in Oman: a countrywide study from the Middle East.

We conducted a cross-sectional analysis to determine the rate of retention in HIV care and the factors associated with loss to follow-up (LTFU) among Omani adults living with HIV who were linked to care as of 31 December 2019. Patients (n = 1610) were identified from a central national HIV surveillance dataset. The majority (68.3%) of patients were male, and the median age was 39 years (IQR, 31-48 years). A total of 1480 patient (91.9%) were retained in care. On multivariate analysis, compared to those who received antiretroviral therapy (ART), patients who had never been on ART were 6.8 (95% CI: 3.05-15.16) times more likely to be lost to follow-up. Patients who had a latest HIV viral load (VL) of 200-999 copies/ml (adjusted odds ratio [aOR]: 4.92, 95% CI: 2.27-10.69) and ≥ 1000 copies/ml (aOR: 15.03, 95% CI: 8.31-27.19) compared to those who had a latest HIV VL of <200 copies/ml had higher odds of loss to follow-up. Moreover, patients who were divorced or widowed were 2.64 (95% CI: 1.14-6.07) times more likely to disengage from HIV services, compared to those who were married. These findings will be invaluable in developing targeted interventions that further improve patients' retention in HIV care in Oman.

Predictors of late presentation and advanced HIV disease among people living with HIV in Oman (2000-2019).

BACKGROUND: The aim of this study was to determine the proportions and predictors of late presentation (LP) and advanced HIV disease (AD) in Oman. LP and AD were defined as presenting with a baseline CD4 count of < 350 and < 200 cells/mm3, respectively. METHODS: We conducted a retrospective database analysis of the National HIV Surveillance System to identify Omani people (≥ 13 years old) who were diagnosed with HIV in the period between January 2000 and December 2019 and had a documented baseline CD4 cell count. We calculated the rates and trend over time of LP and AD. A logistic regression was carried out to determine the predictors of LP and AD. RESULTS: A total of 1418 patients, who were diagnosed with HIV in the period from January 2000 to December 2019, were included; 71% were male and 66% were heterosexuals. The median (IQR) age at diagnosis was 33 (25-39) years. Overall, 71% (95% CI: 68-73) and 46% (95% CI: 44-49) of patients had LP and AD at presentation, respectively. The LP percentage decreased from 76% in 2000-2004 to 69% in 2015-2019; AD percentage decreased from 57 to 46% over the same period. The proportions of men with LP and AD were higher than women (74% vs. 62 and 50% vs. 36%, respectively). The percentages of persons with LP among people aged 13-24, 25-49, and ≥ 50 years were 65, 71, and 84%, respectively. The proportions of persons with AD among people aged 13-24, 25-49, and ≥ 50 years were 39, 46, and 65%, respectively. Logistic regression showed that male sex, older age, having an "unknown" HIV risk factor, and living outside Muscat were independent predictors of AD. Male sex also independently predicted LP. CONCLUSIONS: This analysis indicates that a significant proportion of new HIV cases in Oman continue to present late. This study identified patient subgroups at greatest risk of late HIV diagnosis such as men and older people. Targeted interventions and greater efforts to scale up HIV testing services in Oman are needed.

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.

Validation of GeneXpert testing for SARS-CoV-2 RNA in eight hospital laboratories in Oman.

In response to the current COVID-19 pandemic, numerous commercial assays have been developed for the detection of SARS-CoV-2 for use in the clinical diagnostic laboratories. To date, there is limited comparison of testing methods performed in different hospital laboratory sites. The aims of the study were to evaluate the analytical performance of Cepheid Xpert Xpress SARS-CoV-2 when compared to RT-PCR. This is a cross-sectional study. A total of 155 nasopharyngeal swabs were taken in duplicate from patients presenting with suspected COVID-19 to 8 hospitals in Oman. One swab was tested by the hospital laboratory and the duplicate swab was sent to the national Central Public Health Laboratory (CPHL) for testing. We compared the analytical performance of the commercially available point of care Cepheid Xpert Xpress SARS-CoV-2 assay which was used in the 8 different hospitals with assays including Liferiver, Sansure, TIB MOL BIOL, Kingfisher and COBAS 6800 by Roche which were performed at the CPHL. Testing of the duplicate swabs revealed excellent agreement of results with the viral loads of Ct values ranging from 16-43 for the E gene, 18-44 for the N gene and 17-44 for the ORF gene using the Liferiver assay. The overall sample sensitivity and specificity of the Cepheid Xpert Xpress SARS-CoV-2 assay were both 100% and there was 100% agreement across specimens. We conclude that the rapid GeneXpert and RT-PCR kits assessed in this study may be used for routine diagnostic testing of COVID-19 patients by experienced clinical microbiology diagnostic laboratories. Our results highlight the importance of rapid molecular testing at different sites within a country in a public health emergency.

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.

Elimination of mother-to-child transmission of HIV in Oman: a success story from the Middle East.

BACKGROUND: In January 2016, the National AIDS Programme (NAP) in Oman introduced a package of interventions, including capacity building for service providers, to improve the quality of HIV services. AIMS: To report the impact of these interventions on the rate of vertical HIV transmission in the period from January 2016 to December 2019. We also describe the virological and obstetric outcomes for HIV-infected pregnant women. METHODS: This was a medical record review of 94 HIV-positive pregnant women (median age 32 years; interquartile range 25-34 years) reported to NAP in 2016-2019. RESULTS: There were 110 pregnancies in 94 women. The majority (75.3%, 61/81) of women were diagnosed with HIV infection from routine antenatal screening, with 60% (66/110) of pregnancies occurring in women who knew their HIV status at conception. Caesarean section was the most common (50%) mode of delivery. The preterm labour and low birth weight rates were 21.2% and 15.9%, respectively. The antiretroviral coverage during pregnancy was 95.5%, with most (87.8%) women reporting excellent or good adherence. The majority (81.6%) of women achieved HIV viral load of < 400 copies/ml at or near delivery. Almost all infants (99%) were given prophylactic antiretrovirals. The rate of mother-to-child transmission of HIV was 1%. CONCLUSION: The obstetric and virological outcomes for HIV-infected pregnant women delivered in 2016-2019 were favourable, with a low rate of mother-to-child transmission of HIV. Oman is now in the process of finalizing application of World Health Organization validation of elimination of mother-to-child transmission of HIV.

The role of supporting services in driving SARS-CoV-2 transmission within healthcare settings: A multicenter seroprevalence study.

OBJECTIVE: To determine the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in healthcare workers (HCWs) based on risk of exposure to COVID-19 patients. METHOD: This was a SARS-CoV-2 seroprevalence cross-sectional study in risk-stratified HCWs randomly selected from three main district hospitals in Oman. RESULTS: 1078 HCWs were included, with an overall SARS-CoV-2 seroprevalence of 21%. The seropositivity rates in low-, variable-, and high-risk groups were 29%, 18%, and 17%, respectively (p-value < 0.001). The study found higher positivity in males (crude odds ratio [COR] 1.71, 95% confidence interval [CI] 1.28-2.3), and workers residing in high-prevalence areas (COR 2.09, 95% CI 1.42-3.07). Compared with doctors, workers from supporting services, administration staff, and nurses were more likely to test positive for SARS-CoV-2 antibodies (COR 9.81, 95% CI 5.26-18.27; 2.37, 95% CI 1.23-4.58; 2.08 95% CI 1.14-3.81). The overall rate of previously undetected infection was 12%, with higher values in low-risk HCWs. High district prevalence was a driving factor for seropositivity in the low-risk group (adjusted odds ratio [AOR] 2.36, 95% CI 1.0-5.59). CONCLUSION: Low-risk supporting services workers can drive SARS-CoV-2 transmission in hospitals. More attention and innovation within this area will enhance the safety of health care during epidemics/pandemics.

Predictors of virologic failure among people living with HIV in Oman: a national study from the Middle East.

We conducted a cross-sectional analysis to determine HIV virologic failure and its associated factors among Omani people living with HIV who are on ART for > 6 months. Patients (n = 1427) were identified from a central national HIV surveillance dataset. Two-thirds (67%) of patients were male, and the median age was 39 years (IQR, 32-48 years). Out of 1427 patients, 14.4% had virologic failure (HIV viral load [VL] ≥ 200 copies/ml). The multivariate analysis showed that patients aged 25-49 years (adjusted odds ratio [aOR]: 1.76, 95% CI: 1.01-3.08) were significantly more likely to fail treatment, compared to those aged ≥ 50 years. Besides, having "Other" HIV risk factor (compared to heterosexuals, aOR: 1.82, 95% CI: 1.02-3.24) and receiving HIV care outside the capital Muscat (compared to those cared for in Muscat, aOR: 1.73, 95% CI: 1.11-2.7) were independently associated with virologic failure. HIV viral suppression (85.6%) in Oman is encouraging; however, further strategies, mainly targeting patients who are young (<50 years), those not disclosing their HIV risk factor and those attending HIV treatment centres outside Muscat, are required to enhance HIV treatment outcome in Oman.

The Epidemiology of HIV in Oman, 1984-2018: A Nationwide Study from the Middle East.

We used population-based data on all diagnosed people living with Human Immunodeficiency (HIV) reported to the National AIDS Programme in 1984-2018 to describe the HIV epidemiology in Oman. A total of 3060 Omanis were diagnosed with HIV from 1984 to 2018. The proportions of new infections attributed to sexual contact accounted for 56.3% (376/668) in 1984-1996 compared with 80.7% (630/780) in 2013-2018. Of 1417 patients with a documented CD4 count at the entry of care, 45.3% had a baseline CD4 count of <200 cells/mm3. Compared with heterosexuals, homosexuals had higher rates of advanced HIV disease [42.7% (388/908) vs 50.4% (136/270), respectively]. Rates of advanced disease and death within a year of HIV diagnosis rose consistently with age at diagnosis. Approximately half (48.8%) of the patients diagnosed in 1984-2018 had died by December 2018. The majority (85.6%; 572/668) of people who were diagnosed in 1984-1997 had died compared with 12.7% (99/780) of those diagnosed in 2013-2018. However, people died more recently had a higher proportion of death within a year of HIV diagnosis [74.7% (74/99) in 2013-2018 compared with 13.8% (79/572) in 1984-1996]. This study shows that the HIV epidemic in Oman is a low-prevalence one. Of concern, a large proportion of new HIV diagnoses continued to present late, which has resulted in a substantial increase in short-term mortality over the past 20 years. Nevertheless, we observed a remarkable decline in overall mortality over time, which may be explained by the improvement in the quality of HIV care in Oman.

HIV serology false positivity among expatriates from Africa: a screening dilemma.

HIV prevalence in Oman is low (<5 %); however, 45 % of the population are expatriates, including a portion originating from countries with high HIV prevalence (>5 %). HIV screening is performed at regional public health laboratories as part of a medical fitness programme for residency applicants. We conducted a retrospective evaluation of indeterminate serology results from 11 females of African origin, aged 21-43 years. Serology testing for HIV was conducted according to the national Oman algorithm: fourth-generation immunoassays (Bio-Rad GS HIV Combo Ag/Ab EIA, Siemens Enzygnost HIV Integral 4, Abbott ARCHITECT HIV Ag/Ab Combo, Roche Elecsys HIV Combi PT, bioMérieux VIDAS HIV DUO QUICK), confirmatory assays (Geenius HIV 1/2 Confirmatory, INNO-LIA HIV I/II Score) and PCR testing. Confirmatory testing to resolve indeterminate results was conducted with available samples for five patients using a combination of immunoassays, confirmatory assays, PCR/PERT and pro-viral DNA levels, at three external laboratories; Roche Diagnostics (Germany), Swiss National Laboratory (Switzerland) and Barts Health NHS Trust (UK). Nineteen serum, 15 plasma and two whole-blood samples were analysed. Nine of ten patients analysed on Bio-Rad and Siemens immunoassays were highly reactive; seven were highly reactive on the Abbott assay. Eight of nine patients tested with the Roche assay were negative. Three of four patients tested on the bioMérieux assay were negative. Five patients underwent confirmatory testing at external laboratories; all were negative by HIV-RNA or pro-viral DNA testing. In conclusion, HIV-RNA and pro-viral DNA testing is recommended for HIV screening of individuals from high-prevalence regions coming to low-prevalence regions.

The cascade of HIV care in Oman, 2015-2018: A population-based study from the Middle East.

OBJECTIVE: To evaluate the cascade of HIV care in Oman in 2018 and the longitudinal change in each step from 2015 to 2018. METHODS: Population-based data on all diagnosed people living with HIV reported to the National AIDS Programme in 1984-2018 were used. RESULTS: As of December 31, 2018, the estimated number of people living with HIV in Oman was 3030; 1532 (50.6%) were aware of their infection. Of the diagnosed patients, 95.9% were linked to care, 85.8% were retained in care, and 84.3% were on ART. The proportions of patients with viral suppression out of all people with HIV, the diagnosed persons, and those on ART were 37.3%, 73.7%, and 87.5%, respectively. The proportion of patients linked to care increased from 72.6% in 2015 to 95.6% in 2018 (p < 0.001). Only 57% (947/1661) were retained in care in 2015, which increased to 76.9% (1193/1552) in 2017 and 85.8% (1314/1532) in 2018 (p < 0.001). Viral suppression increased from 75.7% (672/888) in 2015 to 84.5% (859/1017) in 2016 and 87.5% (1129/1291) in 2018 (p < 0.001). CONCLUSIONS: A sustained improvement in linkage to care, retention in care, ART coverage, and viral suppression was observed amongst people living with HIV in Oman in 2015-2018.

First report of human infection with avian influenza A(H9N2) virus in Oman: The need for a One Health approach.

Following the detection of the first human case of avian influenza A subtype H9N2 in 1998, more than 40 cases were diagnosed worldwide. However, the spread of the virus has been more remarkable and significant in global poultry populations, causing notable economic losses despite its low pathogenicity. Many surveillance studies and activities conducted in several countries have shown the predominance of this virus subtype. We present the case of a 14-month-old female in Oman with an A(H9N2) virus infection. This is the first human case of A(H9N2) reported from Oman and the Gulf Cooperation Countries, and Oman is the second country outside of southern and eastern Asia to report a case (cases have also been detected in Egypt). The patient had bronchial asthma and presented with a high-grade temperature and symptoms of lower respiratory tract infection that necessitated admission to a high dependency unit in a tertiary care hospital. It is of urgency that a multisector One Health approach be established to combat the threat of avian influenza at the animal-human interface. In addition to enhancements of surveillance and control in poultry, there is a need to develop screening and preventive programs for high-risk occupations.

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.

HIV Drug Resistance among Patients Failing Therapy at a Tertiary Center in Oman: A Case Record Review.

OBJECTIVES: We sought to estimate the prevalence of HIV drug resistance and describe the common HIV genetic mutations in patients failing antiretroviral therapy (ART). We also investigated the impact of HIV resistance tests results on patients' management. METHODS: We conducted a retrospective record review for all HIV genotypic resistance tests requested at the HIV clinic of a tertiary HIV center in Muscat, Oman, from April 2011 to May 2017. RESULTS: A total of 98 genotypic resistance tests for 84 patients failing ART were analyzed; 82 tests for 69 patients (83.7%, 95% confidence interval: 76.4-91.0) showed resistance to at least one ART drug. M184V/I, K103N/S, and G190A/S/E were the most common mutations detected. Among the tests with a resistant virus, 78.0% were followed by switching ART based on the resistance test profile resulting in virus load suppression after six months in 60.9% of the cases. CONCLUSIONS: HIV drug resistance is very common among HIV patients failing ART in Oman, and should be considered in those patients. Switching ART treatment based on the resistance test result leads to a good virological response in adherent patients.

Clinical and molecular epidemiology of Crimean-Congo hemorrhagic fever in Oman.

BACKGROUND: Crimean-Congo hemorrhagic fever (CCHF) is a serious disease with a high fatality rate reported in many countries. The first case of CCHF in Oman was detected in 1995 and serosurveys have suggested widespread infection of humans and livestock throughout the country. METHODOLOGY: Cases of CCHF reported to the Ministry of Health (MoH) of Oman between 1995 and 2017 were retrospectively reviewed. Diagnosis was confirmed by serology and/or molecular tests in Oman. Stored RNA from recent cases was studied by sequencing the complete open reading frame (ORF) of the viral S segment at Public Health England, enabling phylogenetic comparisons to be made with other S segments of strains obtained from the region. FINDINGS: Of 88 cases of CCHF, 4 were sporadic in 1995 and 1996, then none were detected until 2011. From 2011-2017, incidence has steadily increased and 19 (23.8%) of 80 cases clustered around Eid Al Adha. The median (range) age was 33 (15-68) years and 79 (90%) were male. The major risk for infection was contact with animals and/or butchering in 73/88 (83%) and only one case was related to tick bites alone. Severe cases were over-represented: 64 (72.7%) had a platelet count < 50 x 109/L and 32 (36.4%) died. There was no intrafamilial spread or healthcare-associated infection. The viral S segments from 11 patients presenting in 2013 and 2014 were all grouped in Asia 1 (IV) lineage. CONCLUSIONS: CCHF is well-established throughout Oman, with a single strain of virus present for at least 20 years. Most patients are men involved in animal husbandry and butchery. The high mortality suggests that there is substantial under-diagnosis of milder cases. Preventive measures have been introduced to reduce risks of transmission to animal handlers and butchers and to maintain safety in healthcare settings.

HIV viral suppression in Oman: Encouraging progress toward achieving the United Nations 'third 90'.

OBJECTIVE: To assess the impact of capacity-building interventions introduced by the Oman National AIDS Programme on the quality of HIV care in the country. METHODS: HIV viral load (VL) suppression and loss to follow-up (LTFU) rates were calculated for the period before (in December 2015; n=1098) and after (in June 2017; n=1185) the introduction of the interventions: training, support, and care pathway development. Three HIV VL cuts-offs at last measurement in the year of interest were used to define VL suppression. RESULTS: In the intention-to-treat (ITT) analysis, rates of VL <200 copies/ml and <1000 copies/ml increased from 51.9% in 2015 to 65.5% in 2017 (relative risk (RR) 1.26, 95% confidence interval (CI) 1.17-1.36) and from 58.1% in 2015 to 70.9% in 2017 (RR 1.22, 95% CI 1.14-1.30), respectively; p<0.0001 for both. Similarly, in the on-treatment analysis, rates of VL <200 copies/ml and <1000copies/ml increased from 64.2% in 2015 to 76.9% in 2017 (RR 1.20, 95% CI 1.12-1.28) and from 71.9% in 2015 to 83.2% in 2017 (RR 1.16, 95% CI 1.10-1.22), respectively. Fewer patients were LTFU in 2017 than in 2015 (14.7% (157/1061) vs. 19.2% (188/981); RR 0.77, 95% CI 0.64-0.94). CONCLUSIONS: Achieving the UNAIDS target of 90% of HIV patients on treatment having VL suppression by 2020 is feasible in Oman.