Genetic diversity of cosaviruses in nonpolio acute flaccid paralysis cases of undefined etiology, Northern India, 2010–2011

Abstract

BackgroundNo cases of wild poliovirus have been reported for more than one and a half years from India. Cases of acute flaccid paralysis (AFP) of undefined etiology continue to occur in the region. Despite the recent discovery of the human Cosavirus (HCoSV) in the feces of children from developing countries, there have been no studies of cosavirus infection in India. ObjectivesTo detect and characterize HCoSVs in stool specimens of nonpolio AFP cases by RT-PCR followed by sequencing. Study designA total of 387 fecal samples collected from AFP cases in Uttar Pradesh, India, between May 2010 and April 2011, tested negative on cell culture according to WHO algorithm, were subjected to 5′-UTR region specific RT-PCR followed by sequencing to detect HCoSV. Molecular characterization of HCoSV strains was done by sequencing followed by phylogenetic analysis. Result123 (32%) samples tested positive for cosaviruses and 87 (70.7%) were identified for genetic variants by sequencing a 316-nucleotide interval in the partial 5′-UTR region. Cosavirus strains were characterized as putative species HCoSV-A (n=70; 82%), HCoSV-B (n=7; 8%), HCoSV-C (n=1; 1.1) and HCoSV-D (n=4; 4.5%) while 5 (5%) strains remain uncharacterized. The cosavirus infection appeared highest (63.5%) in younger children, and showed a distinct seasonality, with a late summer peak and winter low. ConclusionThis study demonstrates a diversity of cosavirus strains in circulation, and reports the first investigation of HCoSV infection in children with nonpolio acute flaccid paralysis in India. Currently, this study provides baseline data for further studies of HCoSV infections in children with common enteric infections in India.