We appreciate the comments of Dr Soudeyns and colleagues and would like to address their concerns. The PACTG 1028S study was designed to determine the prevalence of HCV infection in a large cohort of perinatally HIV-infected children. We agree that HCV testing of the entire 219C population would have been ideal; however, this was not feasible. To get a representative sample of the 219C population, subjects were randomly selected to participate in 1028S. We did not include HIV-infected children younger than 1 year to exclude children with maternally transmitted HCV antibody because both enzyme immunoassay and RNA testing (reverse transcription polymerase chain reaction) were performed on all study participants. As Dr Soudeyns and colleagues correctly state, normal aminotransferase levels may be seen in pediatric HCV infection. Although historical medical information regarding liver disease, jaundice, and hepatitis A and/or B infection was obtained for all study participants, serum aminotransferase data were available only from the time of study entry. Thus, it is possible that study participants may have had past ALT abnormalities. Also, this study was not designed to assess mother-to-child HCV transmission. Although we queried all study participants regarding maternal HCV status, maternal HCV serostatus data were available for only half of our study population. Finally, the recommendations for HCV testing are based on the low prevalence of HCV infection we found in children with perinatal HIV infection. As we state, any child with serum ALT abnormalities, maternal HCV infection, or other risk factors for HCV should undergo HCV testing.