Annual report on norovirus in children with acute gastroenteritis in 2009 and their genotypes in Turkey.

In order to determine the incidence, seasonal distribution and clinical characteristics of norovirus in children and analyse the genogroups of norovirus, immunochromatography was used to detect the virus in stool samples. Randomly selected subsets of samples were analysed for genogroups with a multiplex polymerase chain reaction method. Seasonal distribution of norovirus, symptoms, physical and laboratory findings of patients and treatment models were evaluated retrospectively in 2009. In all, norovirus was examined in 520 stool samples. The infection rate was 9.6% (50/520) among patients of acute gastroenteritis in 2009. The virus was mostly detected in the first 24 months of life (50%). Gastroenteritis with norovirus was most frequently found in February, May, July and September. The main symptoms were diarrhoea (100%) and vomiting (95.5%). In some patients affected by norovirus infection higher urine density, ketonuria and high CRP levels were observed. Antiemetic drugs and intravenous fluid-electrolyte therapy were given to 37 (84%) and 26 (59%) of patients, respectively. Hospitalisation was required in 11 patients (25%). All the randomly selected 28 samples (100%) had norovirus genogroup II. In conclusion, norovirus (genogroup II) mostly affected children in the first two years of life and was more frequently observed in February, May, July and September of 2009. Diarrhoea and vomiting were the most frequent symptoms. Antiemetic drugs, intravenous fluid-electrolyte therapy and hospitalisation were usually required in these patients.