Molecular epidemiological study of enteroviruses associated with encephalitis in children from India.

Enteroviruses have been reported in encephalitis cases. However, clinical and epidemiological characteristics of enteroviruses in encephalitis are not fully established. We prospectively investigated 204 children with encephalitis over a period of 2 years (2009 to 2010) for enterovirus. Enterovirus was detected in 45 specimens (22.1%); of these, 40 were typed by seminested reverse transcription-PCR (RT-PCR) and sequencing of the VP1 gene. Molecular typing of enterovirus revealed the predominance of echovirus 21 associated with an epidemic during the rainy seasons of 2010 and the circulation of echovirus 1, coxsackievirus B1, enterovirus 75, enterovirus 76, coxsackievirus B5, and echovirus 19. The nucleotide divergence among echovirus 21 strains was 0 to 2% at the nucleotide level. This study suggests that enterovirus is an important cause of encephalitis in children from India. To our knowledge, this is the first report of echovirus 21 in encephalitis cases worldwide.