Guwahati, Aug 28 - Japanese encephalitis, a mosquito-borne disease, has killed 78 people in eight districts of eastern Assam since April and the health department has sounded a high alert to check its spread, an official said Friday.

A health department spokesperson said close to 1,000 people have been affected by the disease.

'We have alerted health officials across the state to take preventive measures to stop Japanese encephalitis from spreading to newer areas,' Parthajyoti Gogoi, a senior health department official, said.

The disease, transmitted from pigs through mosquitoes, strikes during the peak breeding period from April to September.