AIM:To characterize the prevalence of rotavirus(RV)and adenovirus(AdV)infections in immunocompromised patients with acute gastroenteritis.METHODS:The presence of RV and AdV(serotypes 40 and 41)was evaluated in 509 stool samples obtained between January 2009 and December 2010 from 200 immunocompromised patients(83 females and 117 males;median age 21 years old,range 0-72.The diagnosis of infection was performed as a routine procedure and the presence of RV and AdV(serotypes 40 and 41)was determined by immunochromatography using the RIDA?Quick Rota-Adeno-Kombi kit(r-Biopharm,Darmstadt,Germany).The data analysis and description of seasonal frequencies were performed using computer software IBM?SPSS?(Statistical Package for Social Sciences)Statistics version 20.0 for Mac.The frequencies of infection were compared into different age and gender groups byχ2 test.RESULTS:The study revealed 12.4%AdV positive samples and 0.8%RV positive samples,which correspond to a prevalence of 6.5%and 1.5%,respectively.AdV was more frequent between October 2009 and April 2010,while RV was identified in April 2010 and July 2010.The stool analysis revealed that from the 509 samples,63(12.4%)were positive for AdV and 4(0.8%)positive for RV,which by resuming the information of each patient,lead to an overall prevalence of AdV and RV of 6.5%(13/200 patients)and 1.5%(3/200 patients),respectively.The stratification of the analysis regarding age groups showed a tendency to an increased prevalence of infection in paediatric patients between 0-10 years old.Considering the seasonal distribution of these infections,our study revealed that AdV infection was more frequent between October 2009 and April 2010,while RV infection was characterized by two distinct peaks(April 2010 and July 2010).CONCLUSION:The overall prevalence of AdV and RV infection in immunocompromised patients with acute gastroenteritis was 8%and AdV was the most prevalent agent.