Molecular characterization of hepatitis A virus in children with fulminant hepatic failure in Argentina

Background: Hepatitis A infection, a vaccine-preventable disease, is an important cause of fulminant hepatic failure (FHF) in children in Argentina. Universal vaccination in 1-year-old children was implemented in June 2005. The limited studies about the correlation between the characteristics of the hepatitis A virus (HAV) and FHF have been carried out in adults. Methods: Samples from 41 children with FHF were studied from September 2003 to January 2006 and HAV RNA was detected, sequenced and analysed in the 5′ non-coding region and VP1/2A region. Results: Eighteen HAV strains were characterized and found to be different at the nucleotide level from the self-limited acute infection strains that have been circulating in Argentina with no temporal or geographical pattern. They did not form a genetic cluster, but some of them were identical in the largest fragment characterized and some of them seemed to be more closely related in time and/or geographically. Conclusion: Our results suggest that viral factors could be involved in the severity of the clinical presentation of HAV infection in children in Argentina.