Human metapneumovirus infections among children with acute respiratory infections seen in a large referral hospital in India.

BACKGROUND: Acute respiratory infections (ARI) are the leading cause of morbidity and mortality among children <5 years of age in developing countries. Human metapneumovirus (hMPV), a newly described respiratory pathogen, has been identified as an important cause of ARI in young children. OBJECTIVES: The objective was to describe the prevalence of hMPV in children who presented with ARI to a large referral hospital in Delhi, India and to genotype circulating strains on the basis of F gene nucleotide sequence analysis. STUDY DESIGN: We analyzed 97 samples from children <5 years of age with ARI seen at the All India Institute of Medical Sciences from June 2004 to March 2005. RT-PCR was performed for the N and F genes and partial F gene nucleotide sequences were used to characterize the viruses. RESULTS: hMPV was identified in 12% of children with ARI, including 13% of the children hospitalized with ARI. Most virus identification occurred in the winter. The Indian strains clustered in the A2 genetic sublineage. CONCLUSIONS: This report establishes hMPV as an important cause of ARI in children in India.