Scientists investigating an outbreak of encephalitis among adults in the town of Siliguri, in West Bengal, told the health ministry this week that the disease was caused by a mutant measles virus that affects the brain, lungs, or kidneys. This is India's third outbreak since 1998 of a highly fatal illness involving the brain or the kidneys and attributed to the measles virus. The unexplained outbreak in February this year killed at least 28 people, including two doctors and five nurses in a clinic. The infection spread through droplets in air expelled by patients during the terminal phase of the illness, which is marked by pneumonia.
Epidemiologists say that adequate protection and barrier nursing helped to quell the outbreak.
Investigations had ruled out vector borne infections common in India, such as cerebral malaria or Japanese encephalitis. Tissue samples studied at the National Institute of Virology in Pune showed antibody signatures of measles in 17 samples collected. Measles virus antigen was detected in brain tissues of two patients. The diagnosis has also been confirmed through other tests for the virus. This doesn't look like a one-time event.