[1] Natl Inst Virol, Epidemiol Grp, Pune 411001, Maharashtra, India
[2] Natl Inst Virol, Encephalitis Grp, Pune, Maharashtra, India
[3] North Bengal Med Coll, Dept Microbiol, Darjeeling, W Bengal, India
[4] North Bengal Med Coll, Dept Med, Darjeeling, W Bengal, India
[5] North Bengal Med Coll, Dept Paediat, Darjeeling, W Bengal, India