['A viral origin of biliary atresia (BA) is discussed, and several studies have demonstrated different viral strains in liver biopsies of patients undergoing Kasai portoenterostomy. We hypothesized that the presence of hepatotropic viruses in patients undergoing portoenterostomy contributes to the progression of the disease and negatively affect the outcome.', 'Liver biopsies were prospectively taken from 70 patients undergoing portoenterostomy in our department from April 1996 to April 2004. Samples were screened by polymerase chain reaction for all common hepatic viruses. Primary outcome parameter was survival with the native liver. Secondary parameters were postoperative serum activity of liver enzymes and serum bilirubin levels at different time points. Patients underwent regular follow-up until October 2008.', 'Twenty-eight patients (40%) were positive for 1 or more hepatotropic viruses. Four patients were lost to follow-up. In the remaining 66 patients, there was no significant difference in survival with their native liver between virus-positive and virus-negative patients. After a mean follow-up of 7.7 years (range, 4.6-16.1 years), 15 (23%) of 66 patients still lived with their native liver. There was no difference in liver enzymes, C-reactive protein, or bilirubin at any time point between both groups.'] Does detection of hepatotropic viruses have no impact on the prognosis after Kasai procedure?