Characterization of non-polio enterovirus isolates from acute flaccid paralysis children in Pakistan reflects a new genotype of EV-107.

Enteroviruses comprise a group of genetically diverse RNA viruses that usually cause respiratory illnesses, myocarditis, enteritis, meningitis, encephalitis and poliomyelitis. In this study, 23 non-polio enteroviruses, isolated during September-October 2009 from stool specimens of children suffering from acute flaccid paralysis (AFP) were subjected to serotype determination by using RIVM antiserum pools. Twenty-two isolates were identified as members of human enterovirus B (HEV-B) species except one that remained untypeable. Phylogenetic analysis of the untypeable isolate (PAKNIH-2009/23) based on the sequence of 5'UTR, capsid and 2A regions confirmed that this isolate is closely related to TN94-0349 strain of EV-107 serotype with 70.4% nucleotide similarity in VP1/2A junction, 79.4% in the capsid coding region and 89.1% in 5'UTR region respectively. Our data strongly suggests that PAKNIH-2009/23 is a genetically distinct strain of EV-107 currently circulating in Pakistan. This study also highlights the probable role of non-polio viral etiologies associated with AFP and needs to plan new strategies especially during the post polio eradication era.