Epidemiology and genetic relatedness of measles virus infection in Uttar Pradesh, India, during 2009-2010.

Measles surveillance and epidemiological investigation are beneficial tools for genetic analysis and documentation of the interruption of transmission of endemic measles. In this study, areas of Uttar Pradesh, India, associated with measles outbreaks were investigated. Random blood and urine samples were collected from clinically defined cases. The cases were investigated through extensive house-to house surveys. The cases were diagnosed clinically and serologically, and through genotyping of the virus. All of the cases were found to be serologically positive for measles. In the studied population, a 1.9% case fatality rate and an overall 16% attack rate of measles virus were found. Out of 10 outbreak areas, the measles virus D8 genotype was found in nine, and the D8 and A genotypes were found in the remaining area. This study calls for an improved surveillance system and intensive characterization of genotypes in circulation for the measles elimination program in India.