High frequency of enterovirus serotype circulation in a densely populated area of India

In the state of Uttar Pradesh in India, enteroviruses are a significant cause of infection presenting in endemic or epidemic forms. The present study aimed to use molecular methods to identify enterovirus serotypes in clinical specimens to determine their circulation in the community.

A total of 320 clinical specimens were collected between January 2009 and December 2010 from children younger than 15 year of age in northern India. Reverse- transcription (RT) real time PCR and semi-nested RT PCR targeting the 5'untranslated region and VP1 region was used for the detection and identification of enterovirus serotypes.

The enterovirus genome was detected in 79 (24.7%) of 320 clinical specimens by real time PCR. Central nervous system syndrome (CNS) was the most common clinical manifestation (n=32, 62.74%), followed by respiratory tract infection (n=8, 15.69%), acute febrile illness (n=7, 13.73%), and gastrointestinal disease (n=4, 7.84%). A total of 32 different serotypes were identified with the predominance of coxsackievirus B5 and echovirus 6. Phylogenetic analysis of partial VP1 gene sequences from this study showed that many enterovirus serotypes showed good similarity with strains from America and Europe in comparison to neighbouring Asian countries.

To our knowledge this is the first study of enterovirus prevalence from northern India based on unbiased molecular methods which leads to the identification of fifteen different enterovirus serotypes. The high frequency of enterovirus B species serotypes circulation may be an important cause of CNS infection in the children of this region.