The virus is zoonotic – it can be transmitted from animals to humans, as well as through contaminated food or directly between people. It can cause a range of illnesses, from subclinical infection to acute respiratory illness and fatal encephalitis (inflammation of the brain).
An outbreak of Nipah affected the northern district of Kozhikode in May before spreading to Kerala. The World Health Organization said that the disease killed 17 people by 1 June before it was contained. There is no known cure for the disease, so travellers should be aware of the risk and avoid close contact with fruit bats or exposure to food and drink potentially contaminated by fruit bats.