New Delhi: A virus without a vaccine has hit Kozhikode in Kerala. Ten people have died after being infected with the virus, including one nurse who was treating the patients. Previous outbreaks of this Nipah virus were reported in India in 2001, from Siliguri.

“Situation under control, no cause for panic,” said Union health minister J.P. Nadda today. In a press release, the ministry said people should not believe in rumours posted on social media and should not spread panic.

They have also said that those who have come in contact with the virus have been placed under observation and further steps are being taken to prevent exposure through animal vectors. “This appears to be a localised occurrence,” said the Central government.

Here’s what you need to know about the deadly virus and the situation in Kozhikode, Kerala.

What is the Nipah virus?

Fruit-eating bats and domestic animals like pigs are hosts for the virus. In Kerala, bats were found inside a well from which victims were drawing water. The virus is also transmitted from contaminated half-eaten fruits, consumed by these animals, or from items like palm wine or toddy. The virus also transmits from humans to humans.

According to the Centers for Disease Prevention and Control (CDC), the virus manifests as an inflammation of the brain. The incubation period is between five and 14 days, and the illness presents itself as fevers, headaches, drowsiness and disorientation. This can become a coma in 24 to 48 hours.

What are the treatment and prevention options?

Treatment options are limited mostly to supportive care.

Prevention measures involve avoiding exposure to risks like infected pigs or bats in endemic areas, and avoiding drinking date palm sap or eating fruits that may have been half-eaten by these bats. Besides this, focused surveillance, effective diagnostics and awareness measures can mitigate outbreaks.

What happened in Kerala?

The first set of deaths was reported in the press Sunday, when three members of the same family died from the Nipah virus. They had died between May 5 and May 19. Another two members of the same family are also being treated for the virus.

What is the government of Kerala doing?

The chief minister of Kerala tweeted that his office is “closely monitoring the spread of the Nipah virus”.

CM Pinarayi Vijayan has informed that Government is closely monitoring the spread of the Nipah virus. Health department is doing everything possible to save the lives of the infected & prevent the advance of virus. — CMO Kerala (@CMOKerala) May 21, 2018

A state-wide alert has been issued, although the virus has been reported in the district of Kozhikode. The state government has also set up a 24-hour control room. Private hospitals have been told not to deny treatment to anyone suffering from fever. Isolation wards have also been set up.

Though the virus has been reported only in Kozhikode, a statewide alert has been given to remain vigilant. A 24-hour control room has been opened to monitor the situation. CM has also requested all to follow the instructions of the health department to tackle this crisis. — CMO Kerala (@CMOKerala) May 21, 2018

What is the Centre doing?

Two teams from New Delhi have been sent by the Central government to investigate the outbreak.

A team headed by Director NCDC reached the spot today and another one consisting of doctors from AIIMS and RML shall be landing tomorrow. GoI is fully committed to extending all support to the state govt. — Jagat Prakash Nadda (@JPNadda) May 21, 2018

The government’s investigation team visited the house where the first set of victims were reported. They found many bats in the well which the family was drawing water from. Some of these bats have been caught and sent to labs for examination. Sixty samples of other materials have also been sent for examination.

The government’s press release today describes the protocol being followed:

“The field team has advised hospitals to follow intracranial pressure (ICP) guidelines, use personal protective equipment (PPE) for healthcare workers and sample collection; assist in enhancing active fever surveillance in the community; strengthen contact tracing in close contacts of cases, relatives, health care workers; ensure isolation facilities, ventilator support and hospital infection control practices; and coordinate with animal sector and enhance surveillance for unusual illness and deaths in animals.”

The Central government is also working to ensure that diagnostic kits, protective equipment and risk communication material is available in both private and public hospitals.

The Centre and state governments are working with resources of the National Institute of Virology, National Centre for Disease Control, Ministry of Health and Family Welfare and Department of Animal Husbandry, Dairying and Fisheries. The Manipal Centre for Virus Research is also involved in the investigation into this outbreak.

Occurrence of the Nipah virus?

The virus was first isolated and identified in 1999 among pig farmers in Malaysia and Singapore. Nearly 300 cases were reported during this outbreak, with over a 100 deaths.

The World Health Organisation (WHO) calls this a “newly-emerging zoonosis”.

In South Asia, a different strain of the virus was detected in Bangladesh in 2001.

Siliguri in India saw an outbreak in 2001. Sixty-six cases were detected, 45 of these patients died. A smaller outbreak was reported in 2007, when all five people who were detected with the virus died.

“Unlike the Malaysian NiV outbreak, outbreaks occur almost annually in Bangladesh and have been reported several times in India,” says the CDC. The CDC also says “Conversely, person-to-person transmission of Nipah virus in Bangladesh and India is regularly reported. This is most commonly seen in the family and caregivers of Nipah virus-infected patients.”