Norovirus detection and genotyping in adult patients with acute gastroenteritis in Tehran

Human Noroviruses (NoVs) are one of the important causes of acute gastroenteritis. NoVs are highly infectious and also spread by person to person transmission through the fecal-oral route. NoVs can be classified into five major genogroups, of which genogroups I and II are recognized as the major cause of NoVs infections in human. There is not enough information about Norovirus gastroenteritis in adult patients in Tehran. The aim of this study was to determine the rate of diarrhea caused by NoVs infection in adult patients with acute gastroenteritis referring to Shohada Hospital in Tehran. From May to February 2008 we collected 67 stool samples from the patients older than 18 years of age with acute gastroenteritis. RNA was extracted and RT-PCR was performed using specific primers which could distinguish between genogroups I and II of NoVs. Three stool samples (4.5%) were positive for NoVs RNA. All of three positive samples obtained in autumn belonged to genogroup I. The mean age of NoVs infected patients was 32+8.7 years. The results of our study revealed the role of NoVs as a cause of gastroenteritis in adult patients. It's also demonstrated that genogroup I of Norovirus is the most prevalent genogroup in adults with acute gastroenteritis in Tehran.