India's southern state of Kerala shut some schools, offices and public transport, authorities said on Wednesday, as they scrambled to rein in the spread of the rare and deadly brain-damaging Nipah virus that has killed two people.

An adult and a child are still infected in hospital, and more than 130 people have been tested for the virus, spread via direct contact with the bodily fluids of infected bats, pigs or people, a state health official said.

"We are focusing on tracing contacts of infected persons early and isolating anyone with symptoms," said the state's Health Minister Veena George, who told reporters the strain of the virus was being examined.

"Public movement has been restricted in parts of the state to contain the medical crisis."

Two infected people have died since Aug.30 in the state's fourth outbreak of the virus since 2018, forcing authorities to declare containment zones in at least seven villages in the district of Kozhikode.

Strict isolation rules were adopted, with medical staff being quarantined after direct contact with the infected.

The first victim was a small landholder in the district's village of Marutonkara, a government official said. The victim's daughter and brother-in-law, both infected, are in an isolation ward, with other family members and neighbours being tested.

The second death followed contact in hospital with the first victim, doctors' initial investigation has shown, but the two were not related, added the official, who sought anonymity as he was not authorised to talk to the media.

Three federal teams, including experts from the National Virology Institute, were set to arrive on Wednesday for more tests, the official said.

The Nipah virus was first identified in 1999 during an outbreak of illness among pig farmers and others in close contact with the animals in Malaysia and Singapore.

In Kerala's first Nipah outbreak, 21 of the 23 infected died, while outbreaks in 2019 and 2021 claimed two more lives.

A Reuters investigation in May identified parts of Kerala as among the places most at risk globally for outbreaks of bat viruses. Extensive deforestation and urbanisation have brought people and wildlife into close contact.