An outbreak of the deadly Nipah virus in India's West Bengal state has sparked concern in parts of Asia, with some tightening screening measures at airports.
Thailand has started screening passengers at three airports that receive flights from West Bengal. Nepal has also begun screening arrivals at Kathmandu airport and other land border points with India.
Two cases have been confirmed in West Bengal since December, reportedly in healthcare workers. Some 196 people who were in contact with them have been traced and tested negative for the virus, India's health ministry says.
The virus can spread from animals to humans. It has a high death range – ranging from 40% to 75% – as there is no vaccine or medicine to treat it.
The Nipah virus can be transmitted from animals, like pigs and fruit bats, to humans. It can also spread person-to-person through contaminated food.
The World Health Organization has described Nipah in its top ten priority diseases, along with pathogens like Covid-19 and Zika, because of its potential to trigger an epidemic.
The incubation period ranges from four to 14 days.
People who contract the virus show a wide range of symptoms, or sometimes, none at all.
Initial symptoms may include fever, headaches, muscle pain, vomiting and sore throat. In some people, these may be followed by drowsiness, altered consciousness, and pneumonia.
Encephalitis, a sometimes-fatal condition that causes inflammation of the brain, may occur in severe cases.
To date, no drugs of vaccines have been approved to treat the disease.
