An outbreak of Nipah virus in India has seen officials scramble to trace close contacts and screening measures introduced at international airports. Initial reports suggested there had been five cases of the deadly infection, with around 100 people quarantined, but health authorities have now confirmed only two infections since December. India’s health ministry said 196 people identified as contacts of the infected people had also been traced and tested negative for the virus.

The ministry added: “The situation is under constant monitoring, and all necessary public health measures are in place.” Some airports in Thailand have reportedly started screening passengers arriving in Bangkok and Phuket from West Bengal, and the country’s parks and wildlife department has implemented stricter screenings at tourist attractions. As the world scrambles to understand Nipah virus and prevent a wider outbreak, here’s everything we know so far.

What is Nipah virus?

Nipah virus is a zoonotic disease that can be transmitted from animals including pigs and fruit bats to humans. It can also be transferred through contaminated food or from human to human.

The virus was first identified during a 1999 outbreak among pig farmers in Malaysia and Singapore.

It has a relatively high fatality rate, with estimates suggesting that between 40% and 75% of people infected will die. The death rate varies between outbreaks depending on local capabilities for identifying and containing cases.

Survivors can suffer lasting neurological problems such as seizures and personality changes, and the virus can sometimes reactivate months or years after initial infection.

Outbreaks have been seen in Bangladesh, India, Malaysia, the Philippines and Singapore.

What are the symptoms and treatment?

Symptoms usually begin with flu-like illness or fever, although people can also be infected without any signs.

Common symptoms are fever, headaches, muscle pain, vomiting and sore throat, sometimes followed by dizziness and drowsiness. In some cases this can progress to pneumonia and severe respiratory problems, seizures and coma.

Health authorities in India havealso been instructed to step up surveillance for Acute Encephalitis Syndrome (AES), a critical condition caused by inflammation of the brain that is common with Nipah virus infection.

There are no specific treatments or vaccines for Nipah. Doctors can give patients supportive care to help them fight the infection.

Could Nipah virus cause a pandemic?

Nipah virus inspired the 2011 Hollywood thriller, Contagion, which featured a fictional virus that triggers a global crisis.

There has never been a case recorded in the UK but if the virus mutates to become more easily transmissible, it could quickly spread around the world.

Nipah has been described by the World Health Organisation as a “priority pathogen” due to its pandemic potential.

The UK Health Security Agency also designated it as a high priority pathogen — one that urgently needs investment into new tests, treatments and vaccines — last year.

Can you reduce risk of infection?

The UK Health Security Agency has advised that the risk to tourists is low if they take precautions.

Experts have recommended that anyone travelling to endemic areas should avoid contact with bats and sick animals, and avoid consuming raw of partially fermented date palm sap which can be contaminated with bat poo, urine or saliva.

Fruit should be washed thoroughly with clean water and peeled before eating, and protective clothing should be worn when handling sick animals.

As with all viruses, hand washing can help prevent spread though contact. And you should avoid contact with anyone infected with Nipah virus.