A 39-year-old man tested positive for the Nipah virus in Kerala’s Kozhikode district on Friday, taking the total number of cases in the current outbreak to six, The Indian Express reported.

The man was under observation at a hospital in Kozhikode when he tested positive. He had earlier been admitted at the same private hospital where other patients who tested positive were treated.

There are now four active cases of the virus in the state. One person died this month due to the virus while another death occurred on August 30.

According to the World Health Organization, the Nipah virus is a “zoonotic illness” transferred from animals such as pigs and fruit bats to humans. The virus can also be caught through human-to-human transmission.

It causes fever and cold-like symptoms in patients and in some cases, the infection can cause encephalitis, which is inflammation of the brain, and myocarditis, or inflammation of the heart.

In the wake of the ongoing outbreak, the Kerala government has declared nine panchayats in Kozhikode district as containment zones. In these areas, only shops selling essential goods will be allowed to function from 7 am to 5 pm. However, no curfew timing has been announced for pharmacies and health centres.

Educational institutions throughout the district will stay closed till Saturday, while all gatherings and functions have been prohibited till September 24.

On Thursday, the number of persons under observation increased to 950 as health workers tracked down contacts of confirmed cases. Out of these, 231 have been classified in the high-risk category, while 21 have been hospitalised, according to The Indian Express.

The state government has kept 75 isolation rooms, six intensive care units and four ventilators ready at Kozhikode’s Medical College Hospital.

The Indian Council of Medical Research on Thursday delivered a monoclonal antibody requested by the state government in Kozhikode, The New Indian Express reported. The antibody is the only available antiviral treatment for the infection, although its efficacy has not yet been clinically proven.

The ICMR’s National Institute of Virology also sent its mobile Biosafety level-3 (BSL-3) laboratory to the district to test samples of the virus.

Kerala Health Minister Veena George said that state authorities discussed the stability of the antibody with a central expert committee. “Further steps or course of action would be decided by the expert committee,” she said.

The virus detected in Kerala was the same as one found earlier in Bangladesh, a strain that spreads from human to human with a high mortality rate but has a history of being less infectious.