The Kerala health minister today said the "situation is gradually improving", adding, "The patient confirmed for Nipah is still under treatment and his situation has improved. The Chief Minister has called for an assessment meeting in Kochi tomorrow."

As of now five more people - three nurses treating the 23-year-old man and two of his friends - are being monitored in an isolation ward. Their blood samples have been sent to the NIV for analysis as well. Initial tests on their samples do not point to anything serious, Ms Shailaja said, adding, "The final result is expected either tomorrow or day after."

The source of the latest Nipah virus outbreak is not known. However, the state government has expressed confidence in its ability to deal with the virus. "We have confidence that we can face it. We have faced it in Kozhikode last year and contained it," Ms Shailaja said.

People have been asked not to panic but seek immediate medical attention if fever develops. "We are prepared with all precautionary measures, especially because we have trained staff from the last outbreak in 2018," the health minister said. Isolation wards have been ordered in three districts -- Ernakulam, Thrissur and Kozhikode.

A medicine sourced from Australia after last year's outbreak (and available only with the NIV) will be sent to Kerala, according to Union Health Minister Harsh Vardhan. The medicine was used as a preventive dose for people exposed to the Hendra virus in Australia, which mainly infects large fruit bats (flying foxes) and can be passed on to livestock and people.

The 23-year-old is a student from a college in Idukki district and had stayed in Thrissur recently. According to the district medical officer, he was in Thrissur only for four days and had been suffering from fever. Health officials have begun inspecting all the areas where the student visited over the last few days.

"We have started tracing all the people who have come in contact with this youth, to ensure they monitored, after they are familiarised with the precautionary measures. There is no reason to panic," Ms Shailaja added.

A control room has also been set up and the Strategic Health Operations Centre of the National Centre for Disease Control has been activated, phone number for which is 011-23978046, a health ministry statement said.

The Nipah virus is transmitted from animals to humans and then spreads through people to people contact. It is associated with fatal encephalitis and respiratory illness. In initial stages it causes fever, headache, muscle pain, dizziness and nausea. Risk factors include coming in contact with infected animals such as bats and pigs or humans infected with the virus. Consumption of raw date palm sap also poses a significant risk as the date palms may be contaminated with bat excrement.