Enteric viruses in pediatric diarrhea in Saudi Arabia

Between September 1st, 2002 and August 31st, 2003,a panel of 1,000 stool samples was collected from patients presenting with diarrhea in the three major urban centers of Saudi Arabia; Riyadh, Mecca, and Jeddah. Each sample was tested for rotavirus, and astrovirus by ELISA, G and P type was determined for all rotaviruses. Adenoviruses were sought by hexon-specific PCR and identified by RFLP. A subset of 253 samples was also tested for norovirus by ELISA. Data were analyzed for seasonality of infection, patient nationality and likelihood of hospitalization. Although the overall incidence of rotavirus identification in acute diarrheal stool continued to decline, this was still the virus identified most commonly (6%). Norovirus accounted for 3.5%, astrovirus, 1.9% and adenovirus, 1.4%. Type G9 rotavirus was found to be present (and already common) in 2003, predating its first reported identification in the country in 2004. Most of the virus infections (and most of the G9 detections) occurred in April, the month following the occurrence of the Hajj in the study year. Although most viruses were spread equally in the population, rotaviruses were significantly more common in non-Saudis than in Saudi citizens. Overall the data are consistent with an increase in all virus infections following al Hajj and the potential introduction of novel strains (such as the G9 rotaviruses) by pilgrims. Hospitalization was significantly associated only with norovirus infections.