 The disease is spread through mosquitoes |
The Nepalese authorities say that 140 people have died of Japanese encephalitis - or brain fever - over the past two months. A spokesman for the health ministry said the mosquito-borne disease has affected more than 800 people.
Most of those affected are children and women in the south-western districts of Nepal, bordering India's Uttar Pradesh.
Encephalitis has killed more than 300 people in the state of Uttar Pradesh over the past month.
Vaccines urgently needed
"The government has taken stringent measures to control the dreadful disease and is hectically spraying insecticide and distributing mosquito curtains so that the people may not be affected by it," ministry spokesman Hari Narayan Acharya said, the AFP news agency reports.
Most of the deaths occurred in the Nepalgunj, Banke and Kailali districts, he said.
Mr Acharya attributed the outbreak of the disease to the late delivery of vaccines.
"The vaccines are urgently needed but the purchase tender was not finalised on time which caused the delay in receiving the medicines," he said.
The disease normally spreads through mosquito-bites during the monsoon season, which starts in June and ends in September.