Norovirus Gastroenteritis Outbreak in Kurdistan Province, Iran: Contamination of the Water Supply System

Background: Noroviruses are the most common known causes of non-bacterial acute gastroenteritis worldwide. Norovirus gastroenteritis usually presents with vomiting and diarrhea in the winter.Methods: This cross-sectional study was conducted to evaluate the outbreak of gastroenteritis in one of the villages of Kurdistan Province, Iran, from February 1 to 12, 2019. In this period, 149 people developed joint illness and symptoms of diarrhea, vomiting, and abdominal cramps, whose information was recorded. Data analysis was done with Stata7 software.Results: The attack rate of the total population in the village was 31.17% (26.5% in men and 36.24% in women). The median age of the patients was 26.5 years. The mean patients’ age on the first days of the outbreak was less than on the other days, and this relationship was statistically significant (P=0.003). The most common symptoms were non-bloody diarrhea (57.71%), vomiting (52.34%), abdominal cramps (26.17%), and nausea (24.83%). According to the shape of the epidemic curve, the outbreak was a community-wide outbreak caused by the norovirus.Conclusion: Based on clinical evidence, epidemiological examination, and human and water samples analyses, outbreaks occurred due to the consumption of drinking water contaminated with norovirus. To prevent similar outbreaks, it is recommended to fix the bugs observed in the water supply system and implement the water safety program.