What Is the Nipah Virus, What Is Its Death Rate? Outbreak Kills Boy, Hundreds Isolating

Authorities are working to contain an outbreak of the deadly and contagious Nipah virus in a village in Kerala, India, which led to the death of a 12-year-old boy on Sunday.

Fruit bats, which are also known as flying foxes, are the natural hosts of the virus, and an infection can spread from animals to humans, from humans to humans, and through the consumption of contaminated food, such as fruit.

The Nipah virus can cause severe illness, and the mortality rate is estimated at between 40 percent and 75 percent, according to the World Health Organization (WHO).

An outbreak in Kerala in May 2018 killed 17 of the 18 people who caught the virus, and more than 2,500 close contacts of patients had to be monitored as part of the outbreak response.

The state's health minister Veena George said on Monday that 251 people who came in contact with the child have been identified, including 129 healthcare workers.

All of them are in self-isolation, and 11 have developed symptoms of the infection, though they are said to be in a stable condition.

Authorities are working to identify the source of the outbreak, which is suspected to be contaminated fruit.

"The family of the victim had stated about the frequent presence of fruit bats at their property, where there are rambutan trees," said George, via The Indian Express.

"Samples of half-eaten rambutan fruits, which could be either bitten by bats or pecked by birds, were collected. Besides, a habitat of fruit bats has been spotted at the other side of a river near the victim's house.''

An area within a three-kilometer radius of the child's house in Chathamangalam has also been declared a containment zone.

Drug therapies and vaccines that can specifically combat the Nipah virus infection are currently in development, which means that treatment is currently limited to intensive care, pain relief, and the treatment of specific symptoms as they occur.

Nipah virus symptoms are wide-ranging and can take as long as 45 days to emerge, though the typical incubation period is believed to be between four and 14 days.

Some people who contract the virus can be asymptomatic.

However, early symptoms can include fever, headaches, muscle pain, coughing, vomiting, difficulties breathing, and a sore throat.

More serious illnesses can follow, such as disorientation, drowsiness, confusion, severe respiratory problems, and seizures.

In some cases Nipah virus can lead to encephalitis, which is an inflammation of the brain that can leave patients comatose, and can also cause long-term health issues.

The WHO says that around 20 percent of those who survive acute encephalitis develop further neurological consequences, which can include personality changes or epilepsy. In some cases, an initial recovery can precede delayed onset encephalitis.

A rotten mango with a bite mark
Fruit bats, also known as flying foxes, are the Nipah virus' natural hosts, and can spread it by contaminating food. frank600/iStock