New encephalitis outbreak in India's Uttar Pradesh 8 October 2013 Last updated at 07:42 Fifteen children have died in the past few days in a fresh outbreak of viral encephalitis in India's Uttar Pradesh state, taking this year's toll to 358. The disease usually occurs during the monsoon season in Gorakhpur and adjoining areas and children are the worst affected. More than 200 patients are still being treated at government hospitals. At least 6,500 children have died of encephalitis in the region since the first case was detected in 1978. Gorakhpur and adjoining districts which border Nepal in the foothills of the Himalayas are low-lying and prone to floods, providing a breeding ground for mosquitoes which commonly transmit the virus. The Press Trust of India on Tuesday reported that 15 children had died of the disease in the past few days, taking this year's toll in the state to 358. Doctors say affected patients come from between 10 and 12 districts in the region, and are mostly the rural poor. Until 2005, doctors say that the the majority of deaths were caused by Japanese encephalitis, a mosquito-borne virus. Regular outbreak But in the past seven years, children have been dying of other forms of viral encephalitis, the exact cause of which is unclear. The diseases cause headaches and vomiting and can lead to coma, brain dysfunction, seizure and inflammation of the heart and kidney. Doctors say children between the age of six months and 15 years are the worst affected. A fifth of the children who survive have to live with neurological weaknesses, doctors say. The government says it has tried to check the regular outbreak of encephalitis in the region. Last week, India launched a vaccine against Japanese encephalitis as part of a national programme to fight the virus. "Beginning with the first report in 1955 in Tamil Nadu state, the Japanese encephalitis virus has now spread to more than 171 districts in 19 states," Health Minister Ghulam Nabi Azad said at the launch of the vaccine. In 2005, a virulent outbreak of Japanese encephalitis in Gorakhpur killed 1,000 people, mostly children. This was the worst outbreak since 1978.