Ramya Kannan

CHENNAI: To rid eight districts of Tamil Nadu, known to be endemic to potentially life-threatening Japanese encephalitis, the Government will launch a campaign to vaccinate 24 lakh children in the age group of 1-15.

To be launched in Virudhunagar, Villupuram and Cuddalore as a 15-day campaign on Tuesday, the intensive drive will try to cover all the children in the age group. Over the past week, some cases of suspected Japanese encephalitis reported from certain districts sparked a sense of panic in the affected districts. It has been a source of worry for public health experts that Japanese encephalitis, as it is more commonly known, is ‘endemic,’ or occurs regularly in eight districts in Tamil Nadu. These districts are Perambalur, Villupuram, Virudhunagar, Cuddalore, Madurai, Tirunelveli, Thanjavur and Tiruchi, Joint Director of Public Health S. Elango told The Hindu.

Auto disable syringes would be used to administer the vaccine to children in special immunisation centres, anganwadis and noon-meal centres, he said. The vaccine, imported from China, is a live, weakened form of the virus, and is not known to have any side-effects. It will provide lifelong immunity against the disease, which is caused by the mosquito-borne Japanese encephalitis virus, from the family Flaviviridae. The transmission is through the bite of the Culex mosquito, but pigs serve as amplifier hosts.

It affects children, and is known to cause, coma, mental retardation, and even death. The State has not encountered Japanese encephalitis in epidemic proportions ever: there were a total of 18 cases, with one reported death; 17 ‘suspected cases’ have been reported this year. Director of Public Health P. Padmanabhan said it was still very important to provide protection against Japanese encephalitis because when it affects people, the rate of mortality was 40 per cent, despite the best care. “Even those who recover, the children, might have to live with disabilities.”

It has been identified that the problem occurs in different districts that have agriculture-intensive activities, especially paddy cultivation. “Paddy cultivation requires water to be stagnant in the fields for a long while. We tried drying the fields for a day to see if it could be done. But that is not practical. The only solution, therefore, is vaccination,” he said.

A pilot project conducted in 285 villages in Perambalur, Cuddalore and Villupuram and using another vaccine had resulted in a drastic reduction in the number of cases. The vaccine would be extended to cover non-endemic districts too, Dr. Padmanabhan said.