Kerala, a state in southern India, is dealing with its fourth deadly outbreak of the Nipah virus since 2018. So far, two people, a 49-year-old and a 40-year-old, have died.
As reported by NPR, Malaysian pig farmers were the first known people to become sick from Nipah in 1999. At that time, the virus was not transmissible between humans.
However, the newer strain of Nipah is more deadly, says Dr. Thekkumkara Surendran Anish, an associate professor of community medicine at the Government Medical College in Manjeri, Kerala. "There is virological evidence that the strain we're encountering in Kerala is the Bangladeshi strain," Anish told NPR. This has a high fatality rate of 75% and causes acute respiratory distress, with the higher possibility of human-to-human transmission, he adds.
Symptoms include fever, headache, vomiting, seizures, coma, difficulty breathing, and brain swelling.
According to the CDC, "Long-term side effects in survivors of Nipah virus infection have been noted, including persistent convulsions and personality changes. Infections that lead to symptoms and sometimes death much later after exposure (known as dormant or latent infections) have also been reported months and even years after exposure."
There is no vaccine for this virus.
Bats are the primary means of transmission to humans. From The Guardian:
Flying foxes are the natural carriers of the virus. "It's carried by fruit bats who sit in the tops of trees," said Joanne Macdonald, an associate professor of molecular engineering at the University of the Sunshine Coast. "They can urinate and contaminate fruit, and when people eat that they get the virus and then they get sick."