Recent outbreaks of encephalitis in India have killed around 550 people this year and the toll is likely to rise with health experts saying 70 million children nationwide are at risk.
Uttar Pradesh, the most populous state, and Bihar, further north, are ravaged by encephalitis every year.
A total number of 104 people have died in UP from the mosquito-borne virus which affects mainly malnourished children. The disease causes brain inflammation and can result in brain damage. Symptoms include headaches, seizures and fever.
A total of 309 children have been infected in the state, according to health administration sources. Eighteen per cent children infected with the killer virus had died in UP in 2012, lower than the 37.2% who have lost their lives to the disease so far in 2014. The figures raise questions over initiatives taken by the health and family welfare department to check the outbreak of the disease.
The Japanese Encephalitis was first reported in 1955 in Tamil Nadu. The virus has spread to over 171 districts in 19 states since then.
In Bihar, the official toll from Acute Encephalitis Syndrome stood at 162 on Wednesday. “It covers patients from adjoining districts who were brought to Muzaffarpur for treatment,” a hospital source said on condition of anonymity.
The state has sent blood serums and other pathological samples drawn from affected children to Atlanta in the United States to determine the reason behind the outbreak.
In West Bengal, around 117 people have died of Japanese Encephalitis and Acute Encephalitis Syndrome infections. Although there is a vaccine for JE, victims also die from other forms of the disease, including AES, the exact causes of which are not known.
In West Bengal, chief minister Mamata Banerjee said fumigation had been ramped up to kill mosquitoes, along with health education campaigns for residents.
Hundreds die across the country each year, mainly children, from different forms of the disease, but West Bengal is not normally the worst-hit state.
Encephalitis can be transmitted by mosquitoes from pigs to humans and officials have pointed to the fact that farmers in West Bengal's worst-affected districts breed pigs.
In the northeastern state of Assam, 165 people have died from JE and AES with more than 300 infected with the virus, an official said on Wednesday. Assam chief minister Tarun Gogoi held an emergency meet, directing officials to set up an intensive care unit at each district hospital for the treatment of emergency cases.
Many of the deaths have occurred since the onset of the monsoon season in June when mosquitoes breed in large numbers. According to Dr RN Singh, who is working on Encephalitis cases in UP’s Gorakhpur region, the monsoon may make the virus more active.
(With inputs from agencies)