Epidemiological Surveillance of Norovirus Diarrhea in Hospitalized Children with Acute Gastroenteritis in South of Iran

Background: Noroviruses are one of the most common causes of acute diarrhea in both developed and developing countries. They are responsible for more than 50% of all gastroenteritis outbreaks around the world. Objectives: This study was conducted to assess the prevalence, seasonality and clinical characteristics of norovirus infection in hospitalized Iranian children. Patients and Methods: Between 2008 and 2010, a cross-sectional descriptive study was conducted on 375 stool samples from children under 7 years of age, who suffered from acute gastroenteritis and who were admitted to the Pediatrics Unit of the 17 Shahrivar Hospital in the city of Borazjan. Acute gastroenteritis was defined as > 3 loose watery stools every 24 hours. All the stool specimens were tested for norovirus antigens with enzyme immunoassays (EIA). Demographic and clinical data were analyzed using SPSS software. Results: Of the total collected samples, noroviruses were detected in 47 out of 375 (12.53%). The highest infection rate was among children under two years of age (76.6%) (P = 0.001). Diarrhea (95.74%), vomiting (87.23%) and fever (82.98%) were the most frequently reported clinical symptoms in children with norovirus gastroenteritis. The highest prevalence of the virus was observed in autumn (63.83%) and the lowest in summer (6.38%) (P = 0.015). Conclusions: Regarding the emergence of noroviruses as a relevant cause of acute diarrhea in Iranian children, there is a great need to introduce a routine norovirus testing of hospitalized patients with gastroenteritis, particularly in children under 2 years old during the cold season.