Identification of enteroviral infection among infants and children admitted to hospital with acute gastroentritis in Ho Chi Minh City, Vietnam

A total of 276 fecal specimens collected from infants and children admitted to hospital with acute gastroenteritis in Ho Chi Minh City, Vietnam from October 2002 to September 2003, were tested for the presence of enteroviruses by RT-PCR and virus isolation. Enteroviruses were detected in 27 patients by RT-PCR corresponding to 9.8%. However, only four enterovirus strains could be isolated by cell culture with two different cell lines CaCo2 and Vero, showing specific cytopathic effect (CPE). The results clearly indicate that RT-PCR is a sensitive, specific assay to investigate the true burden of acute gastroenteritis due to enteroviruses in clinical fecal specimens. In the present study, enteroviruses were identified throughout the year except in May and the highest number was in December. Enteroviruses were subjected to molecular analysis by sequencing. It was found that enterovirus strains detected were classified further into two distinct genetic clusters (I, II) and demonstrated the great genetic diversity among them. Based on genetic analysis, 5' noncoding region (5' NCR) sequences suggested the predominant presence of Vietnamese enteroviruses with the greatest similarities to coxsakieviruses (51.9%) and echoviruses (29.6%). Interestingly, two of the sequenced specimens of enteroviruses were similar to a new strain called enterovirus 74. This report is the first detection of enteroviral infection in feces from infants and children admitted to hospital with acute gastroenteritis in Vietnam.