Determinaton of the frequency of rotavirus and adenovirus in children with acute gastroenteritis and molecular epidemiology of rotavirus

Enteric viruses (especially Rotavirus, Norovirus and Adenovirus) are the most common causes of non-bacterial acute gastroenteritis. Aim of this study was to investigate the prevalence of the viral etiology of the gastroenteritis in children aged 0-6 years with acute gastroenteritis and determine predominant genotypes of Rotaviruses. An epidemiological study on common diarrheal viruses was carried out in province of Afyonkarahisar, Turkey, during September 2012-November 2013. Fecal samples obtained from the 492 unvaccinated children with rotavirus vaccine and under 6 years of age who applied to the Pediatric Diseases Outpatient of Afyon Kocatepe University Hospital with the complaint of diarrhea were enrolled into the study. All the fecal samples were evaluated in order to determine presence of the bacterial agents by using bacteriological culture methods and finally no growth observed. Rotavirus and Adenovirus antigens were examined by immunochromatographic method (ICT) (VIKIA Rota-Adeno Casette Test, bio-Merieux, Marcy l'Etoile, France) in stool samples. Rotavirus positive Stool samples with ICT were subjected to reverse transcription-polymerase chain reaction based genotyping of the outer capsid antigens, VP7 and VP4, determining G and P type specificities, respectively. Adenoviruses and Rotavirus were found to be positive in 3.3 %, and 20.3 % of 492 children with acute gastroenteritis respectively. Of the children with viral gastroenteritis, 0.6 % had a mixed adenovirus-rotavirus infection. An increase in the number of cases with rotavirus antigen-positivity was detected in winter and spring months. Of the Rotavirus episodes, 73.0 % were occured during the first two years of life. A total of six different combinations of G and P types were found that included those with combinations of G1, G2, G4, G9 and P[4], P[8] genotypes. The most common rotavirus genotypes were G9P[8] (48.7 %), followed by G9P[4] (17.5 %). Other strains were G1P[8] (16.2 %), G2P[8] (11.2 %), G1P[4] (3.7 %), G4P[8] (2.5 %). Sixty-six percent of our regional rotavirus genotypes were G9P[8] and G9P[4]. The frequency of the positivity of adenovirus was lower than rotavirus. Regarding high frequency rotavirus infection, continuous surveillance is needed in order to inform gastroenteritis prevention programs as well as to provide information about the occurrence of new rotavirus strains. This will assist policy makers in decision making on rotavirus vaccination.