Comparing molecular methods for early detection and serotyping of enteroviruses in throat swabs of pediatric patients.

Abstract

BACKGROUND: Enteroviruses include over 100 serotypes and usually cause self-limited infections with non-specific symptoms in children, with the exceptions of polioviruses and enterovirus 71 which frequently cause neurologic complications. Therefore, early detection and serotyping of enteroviruses are critical in clinical management and disease surveillance. Traditional methods for detection and serotyping of enteroviruses are virus isolation and immunofluorescence assay, which are time-consuming. In this study, we compare virus isolation and two molecular tests for detection and serotyping of enteroviruses in clinical samples. METHODS: One hundred and ten throat swabs were collected from pediatric outpatients with enterovirus-like illnesses (hand-foot-mouth disease, herpangina, and non-specific febrile illness). Virus isolation was conducted using multiple cell lines and isolated viruses were serotyped using immunofluorescent assay. In the molecular tests, a semi-nested RT-PCR and a novel CODEHOP platform were used to detect the 5'UTR and VP1 genes of enteroviruses, respectively. Amplified nucleotides were sequenced and genotyped. RESULTS: Among the 110 cases, 39(35%), 52(47%), and 46(42%) were tested positive with these three tests, respectively. Using the consensus results of these three tests as the gold standard, agreement of the VP1 CODEHOP test was 96%, which is higher than those of the virus isolation (89%) and the 5'-UTR test (88%). The VP1 CODEHOP test also has the best performance on serotyping confirmed with serum neutralization tests. CONCLUSIONS: The VP1 CODEHOP test performed well for detection and serotyping of enteroviruses in clinical specimens and could reduce unnecessary hospitalization cares during enterovirus seasons.