Dengue epidemiological trend in Oman: a 13-year national surveillance and strategic proposition of imported cases.

Dengue fever has emerged as a major public health problem globally in the past three decades. A 13-year national surveillance data analysis was done to describe the epidemiology and its trend of dengue disease in Oman reported between 2001 and 2013. Laboratory-confirmed dengue virus infections reported were studied retrospectively during the study period. A total of 64 laboratory confirmed cases were reported. All the patients contracted the disease during their visit to South-East Asian countries, hence classified as imported cases. The majority of the cases were reported in the year 2012 (23.4%). The most important clinical characteristics were fever (90.6%), myalgia (35.9%) and rash/petechial rash (20.3%). Thrombocytopenia was seen in 31.2% of the study subjects. The mortality was nearly 4.6% and all other patients made a full recovery. The most effective measure for travellers is taking precautions to avoid mosquito bites.

Progress toward elimination of hepatitis B virus transmission in Oman: impact of hepatitis B vaccination.

Approximately 2-7% of the Omani population has chronic hepatitis B virus (HBV) infection. To decrease this burden, universal childhood hepatitis B vaccination was introduced in Oman in 1990. The hepatitis B vaccination strategy and reported coverage were reviewed. To assess the impact of the program on chronic HBV seroprevalence, a nationally representative seroprevalence study was conducted in Oman in 2005. Since 1991, hepatitis B vaccination in Oman has reached almost every eligible child, with reported coverage of ≥ 97% for the birth dose and ≥ 94% for three doses. Of 175 children born pre-vaccine introduction, 16 (9.1%) had evidence of HBV exposure, and 4 (2.3%) had evidence of chronic infection. Of 1,890 children born after vaccine introduction, 43 (2.3%) had evidence of HBV exposure, and 10 (0.5%) had evidence of chronic infection. Oman has a strong infant hepatitis B vaccination program, resulting in a dramatic decrease in chronic HBV seroprevalence.

Epidemiology of invasive pneumococcal infection among hospitalized children aged less than 5 years in Oman.

The objective of this study was to describe the epidemiology of invasive pneumococcal disease (IPD) in Omani children. We retrospectively reviewed cases admitted in children <5 years of age who were admitted in one of 4 tertiary care facilities within the Muscat Governorate. These cases represented nearly 95% of all IPD admissions recorded throughout the country from 1 January 2006 to 31 December 2006. Cases of IPD were identified using the ICD-10 discharge code. Case definition required microbiological confirmation (i.e., isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid or any other normally sterile biological fluid) or clinical diagnosis in the absence of a specimen. A total of 41 cases of IPD were identified. The annual incidence of IPD was 26.1 per 100,000 in children <2 years old and 18.6 per 100,000 in children <5 years old. Among the reported IPD cases, 22 (54%) isolates were resistant to at least one antibiotic and 15 (37%) of patients had a known comorbid medical condition. These results demonstrate that the incidence of IPD in Oman during 2006 was high compared to many of the neighboring countries and provides baseline data on the incidence of IPD in an era before the introduction of the pneumococcal conjugate vaccine (PCV). In light of evidence for a significant incidence of IPD, we recommended that a nationwide surveillance system be put in place to monitor the incidence of IPD in children <5 years of age in Oman and to document the impact of PCV.