Why in the news?
- A child mortality in Kerala has been reported, after being infected with the Nipah virus recently.
What is Nipah virus?
- Nipah virus (NiV) is a ‘zoonotic’ virus, that is, it is transmitted to human beings from animals. The virus can also be transmitted through contaminated food, or directly between people.
- The pathogen that causes NiV encephalitis is an RNA virus of the family Paramyxoviridae, genus Henipavirus, and which is closely related to the Hendra virus (HeV), which was isolated in Australia in 1994.
- The animal host reservoir for both HeV and NiV is the fruit bat, which is commonly known as the ‘flying fox’.
- Infected fruit bats can spread the disease to other animals as well, such as pigs — and also dogs, cats, goats, horses and sheep.
- Human beings can get infected if they come in close contact with the infected animal — bats or other animals such as pigs or its body fluids such as saliva or urine.
- The initial jump of the virus from animal to human is known as a ‘spillover’ event in an outbreak.
- Once the infection has moved to humans, person-to-person spread of NiV can occur.
Nipah virus: What are the symptoms, and how dangerous is it?
- NiV infection can cause a mild to severe disease, which in the latter situation sees a major swelling in the brain (encephalitis), and can lead to death.
- Symptoms of the infection can appear at any time from four days to two weeks after exposure to the virus. Patients usually report a fever and headache that can last from three days to a couple of weeks, accompanied by symptoms of respiratory illness such as cough, sore throat, and difficulty in breathing.
- If the disease progresses to encephalitis, the patient may experience drowsiness, disorientation, and mental confusion, which can then progress very quickly to a coma within 1-2 days.
- Between 40 per cent and 75 per cent of cases can lead to death, according to the World Health Organisation (WHO). However, the fatality rate in the 2018 outbreak in Kozhikode was well over 90 per cent.
- Those who have survived the disease have reported long-term side effects, among them persistent convulsions and, in some cases, changes in personality.