Health officials are seen at the isolation ward of Ernakulam Medical College in Kochi, India on June 4, 2019. (Xinhua/Stringer)

 
Authorities in India's southern state of Kerala have heightened surveillance measures to contain the spread of Nipah infections, officials said on Saturday.

The measures have been stepped up in Kozhikode district, where so far six cases have been identified. Of them, four are active while the remaining two died.

The state-run broadcaster All India Radio (AIR) said that so far 1,080 people have been included in the contact list of Nipah-infected patients in Kozhikode, of which 297 people are in the high-risk category.

"Those in the contact list are kept in isolation and their body fluids have been sent for testing," the broadcaster quoted officials as having said.

According to AIR, health workers covered more than 15,000 houses in Kozhikode so far, as part of their field survey.

Reports said after a resident in Cheruvannur tested positive for Nipah on Friday, local administration declared the five-kilometer area around the residence as a containment zone.

Health officials wearing protected gear at the isolation ward of Ernakulam Medical College in Kochi, India on June 4, 2019.(Xinhua/Stringer)

 
A strict perimeter control has been imposed in several localities falling under Kozhikode Municipal Corporation. The officials have put up barricades to limit access to these areas.

The district administration in Kozhikode has directed all educational institutions to hold classes online for the students till Sept. 24.

Meanwhile, the Director-General of India's top health research body - Indian Council of Medical Research (ICMR), Rajiv Bahl, on Friday said they have reached out to Australia to procure 20 more doses of monoclonal antibodies for the treatment of Nipah virus infection.

"We got some doses of monoclonal antibody from Australia in 2018. Currently, the doses are available for only 10 patients," Bahl said, adding globally monoclonal antibody has been given to 14 patients infected with Nipah virus outside India and all of them have survived.

According to Bahl, no one so far has been administered the medicine in India.

"Twenty more doses are being procured. But the medicine needs to be given during the early stage of the infection," he said. "It can only be given as compassionate use medicine."

Bahl said teams from ICMR's National Institute of Virology (ICMR-NIV) and National Institute of Epidemiology (ICMR-NIE) have been deployed on the ground and are working with authorities in Kerala to strengthen containment efforts.

He also advised that people take certain precautionary measures against Nipah, including handwashing, avoiding contact with body fluids of infected or suspected cases, avoiding areas where bats are known to roost and contact with bats and avoiding consumption of raw foods that may be contaminated by bats, such as raw date palm sap or raw fruits.

Kerala had first witnessed an outbreak of the Nipah virus in 2018 in Kozhikode and Malappuram districts, claiming 17 lives.

According to WHO, Nipah virus infection is a newly emerging zoonosis that causes severe disease in both animals and humans. The natural hosts of the virus are fruit bats of the Pteropodidae Family, Pteropus genus.

Typically, the human infection presents as an encephalitic syndrome marked by fever, headache, drowsiness, disorientation, mental confusion, and coma, which can potentially lead to death.