Epidemiology of pandemic H1N1 strains in a tertiary hospital of Maharashtra.

Swine-flu is a viral fever caused by a new mutated strain Influenza A virus subtype H1N1, which infects humans. Pandemic H1N1 (pH1N1/2009) virus was detected in the first quarter of 2009 in the west coastal region of North America and spread very rapidly to the other countries during April-June, 2009. This study was conducted to assess the epidemiology of pandemic H1N1 strains using a cross-sectional study design in a tertiary hospital. The symptomatic patients attending the flu outpatient department (OPD)/emergency from August 2009 to April 2011 at Indira Gandhi Government Medical College, Nagpur were included using a standard case definition. A total of 67 (27.01%) samples from 247 patients were pandemic influenza A/H1N1 positive. None of the patients had a history of foreign travel, whereas 23.88% of the patients gave history of travel to an endemic area. Overall, 22.38% of the patients came in contact with proven cases of pandemic H1N1. pH1N1 transmission activity has increased since May 2010.