Nipah symptoms range from asymptomatic infection, acute respiratory infection and encephalitis. (File)

Kerala Health Minister KK Shailaja said today that the sample of one more person suspected to be infected with the Nipah virus has tested negative.

He was being treated at the isolation ward of the Medical College Hospital in Kochi, the minister told reporters in New Delhi.

The government on Thursday announced that samples of six people, including three nursing staff, who had initially attended on a college student infected with Nipah virus, had tested negative. The results of the blood tests of the six people have come as a huge relief for Kerala authorities trying to stop the spread of the highly infectious virus that had left 17 people dead in the state last year.

The condition of the college student, diagnosed with Nipah infection, is stable and a total of 314 people who were in touch with the infected person have been kept under observation, a Union Health Ministry official said in New Delhi on Thursday.

He is being treated at a private hospital. "He is taking food. He spoke to his family members through intercom. Fever has subsided," a government bulletin said.

Ms Shailaja said the six of them, who tested negative, had direct contact with the Nipah-infected patient.

"There is no need for any concern. Result of the sample of the seventh person is also negative," she said.

They are currently being treated at the isolation ward of the Government Medical College Hospital, Kalamassery.

The minister said she will seek more funds from the central government to set up a virology institute at least of Level 3 standard in Kerala.

The government has also urged the people to continue to take precautionary measures to prevent spread of the disease.

The Union Health Ministry has deployed a six-member team comprising an epidemiologist to conduct contact-tracing for early detection of suspects and review of isolation facilities.

A designated control room has been established at the district collector's office and an isolation ward established at the Government Medical College in Ernakulam, the Health Ministry had said in a statement on Tuesday.

According to the World Health Organisation (WHO), Nipah virus is a newly emerging disease that can be transmitted from its reservoir (natural wildlife host), flying foxes (fruit bats), to both animals and humans. Symptoms range from asymptomatic infection, acute respiratory infection and encephalitis.

Infected people initially develop influenza-like symptoms of fever, headache, vomiting and sore throat. This can be followed by dizziness, drowsiness, altered consciousness, and neurological signs that indicate acute encephalitis.