Seasonality and prevalence of rotavirus in Al-Ain, United Arab Emirates

Background: Rotaviruses are the single most important causative agent of acute neonatal enteritis in most avian and mammalian species including humans. Rotaviruses infections have also been shown to be associated with the elderly, immunocompromised individuals and more recently with epidemic diarrheal illness in adults. Objectives: To study the incidence and the effect of seasonality on the prevalence of rotaviruses in Al-Ain, United Arab Emirates. Study design: A total of 650 stool samples submitted to the laboratories of two University Teaching Hospitals (Al-Ain and Tawam) and a private hospital (Oasis) were examined for the presence of rotaviruses from January 1990–December, 1992, using a commercially available latex agglutination assay. The meteorological data (temperature, relative humidity and rainfall) recorded during the sampling period was analyzed statistically to examine the effect of seasonality on the prevalence of rotavirus cases in Al-Ain, United Arab Emirates. Results: Rotavirus was detected in 21.4% of the samples examined. The predominant number of positive cases (35%) were in the 7–12 months age group. It was interesting to find rotavirus-positive cases in as low an age group as <3 months (3.6%) and as high as 10 years (8.04%). There was no significant difference on infection rates between male and female groups in the study. However, there was a significant difference between the national (38.18%) and non-national children (61.28%). The higher rate of the latter may be due to import of infections. There appeared to be a seasonal pattern of rotavirus occurrence in the cases studied, with a marked increase in the number of positive cases during the months when the relative humidity was low (25–45%) and there was no rainfall. Conclusions: Rotavirus was detected in all age groups with a predominance in 7–12 month age groups, and a higher incidence in non-nationals. There was a marked increase in the number of positive cases during the months when the relative humidity was low (25–45%) and there was no rainfall. These findings are discussed in relation to the epidemiology and prophylaxis of rotavirus infections.