Kerala Chief Minister Pinarayi Vijayan on Tuesday said the Nipah outbreak in the Kozhikode district is under control, but cautioned that the threat of the infectious disease is not over yet, reported PTI.

The Nipah virus infection 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.

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

Kerala has reported six cases of Nipah virus. Of these, two people have died, while four others, including a nine-year-old boy, are undergoing treatment.

The chief minister said that nine people are under observation at Kozhikode Medical College.

Vijayan said it was not possible to rule out the chance of a second wave of the Nipah outbreak in the state.

“It cannot be said that the threat of Nipah is completely over,” the chief minister said, according to PTI. “The health system is working cautiously. Early detection of the virus averted a dangerous situation.”

He also added that even the Indian Council of Medical Research could not provide a clear answer to why Nipah cases were being reported from Kozhikode.

Meanwhile, Kerala’s disaster management department has relaxed restrictions in the containment zones of nine panchayats in Kozhikode after no new cases of the Nipah virus infection were reported in the state, reported ANI.

Kozhikode District Collector A Geetha announced that shops in the containment zones can now operate till 8 pm, while banks are allowed to remain open till 2 pm.