The Kerala government said on Wednesday that the condition of a college student who is being treated for the Nipah virus was stable, while five others who are suspected of having contracted the virus were improving, PTI reported.

“The condition of the student is stable. It has not turned worse,” Health Minister KK Shylaja said. A medical bulletin said the student was admitted to a private hospital on May 30 and “the patient is clinically stable, slowly improving and his fever is subsiding”.

The government had put Thrissur, Kollam, Ernakulam and Idukki districts on high alert after the 23-year-old student was diagnosed with Nipah virus on Tuesday, Mint reported. The districts were on alert as the student had recently reportedly travelled through the region.

Nearly 311 people, who came in contact with the patient over the last two weeks, are under observation to prevent the spread of the virus. Four of them, who developed fever and complained of uneasiness, have been shifted to an isolation ward at the government medical college hospital in Kalamassery in Ernakulam, The Indian Express reported. One more person, who is not one of the people on the list, in Vadakkekara region in Ernakulam was kept in isolation ward with suspected symptoms.

Shylaja said on Wednesday that the samples of all five people have been sent to National Institute of Virology in Pune. “The preliminary assessment of their health shows that they are not in a severe condition,” she said. “Their health now is better than yesterday. But they are under constant watch of doctors. We expect tests of their blood samples would be negative. But we should wait till the final results come.”

Shylaja said treatment for Nipah will begin only if their blood tests show they have contracted the virus. “We should be very careful till the completion of the incubation period of the virus,” she said. The test results are expected by Thursday evening.

Nipah is a virus that can be transferred from animals to humans. It causes fever and cold-like symptoms in patients before quickly advancing to encephalitis, which is inflammation of the brain, and myocarditis, or inflammation of the heart. There is no vaccine or cure for Nipah infections at present. An outbreak of the virus in Kerala in May 2018 had claimed 17 lives.

The man tested positive for the Nipah infection after the National Institute of Virology in Pune, Maharashtra tested his serum samples, Kerala’s Health Minister KK Shailaja said on Tuesday.

The government has launched a search for the source of the virus, Firstpost reported. Last year, scientists found that the virus had spread from a 26-year-old man in Kozhikode district who had contracted it after consuming a fruit bitten by a fruit bat. However, this year’s patient had stayed at multiple places in three districts during the weeks before being tested positive.

Shailaja on Tuesday asked people to not panic and to take precautions. The Union Ministry of Health has deployed a six-member team to help the state, she said. “There are certain hygiene precautions that need to be maintained when in public places,” she said, according to The Hindu. “The disease becomes infectious only when symptoms appear and not during the incubation period.”

The administration has set up helpline numbers 1077 and 1056 as part of steps to tackle the virus.