A deadly virus has killed at least three people in southern India, officials said on Monday, with medical teams dispatched to the area amid reports that up to six other people could have died from the disease and others are ill.

The three fatalities from the Nipah virus were all from the same family, said Kerala state health minister K.K. Shailaja.

There is no vaccine for Nipah, which can cause raging fevers, convulsions and vomiting. The only treatment is supportive care to control complications and keep patients comfortable. It has a mortality rate of up to 75 per cent.

Media reports say five more people have died from high fevers in recent days, as well as a nurse who had treated people infected with the virus. But medical workers have not yet confirmed what killed those people.

At least eight others sick with Nipah symptoms are being monitored.

People who had been in contact with Nipah victims have been put into isolation, Shailaja said.

Nipah, which was first identified during a late 1990s outbreak in Malaysia, can be spread by fruit bats, pigs and through human-to-human contact.

A team from India's National Centre for Disease Control has been sent to the coastal region of Kerala, where the outbreak occurred.

“We are closely monitoring the situation,” India's health minister, J.P. Nadda, said in a statement.