Nipah virus (NiV) infection is a newly emerging zoonosis that causes severe disease in both animals and humans and at present, there is no vaccine or drugs to combat the Nipah virus infection.
Nipah virus (NiV), an RNA virus belonging to Paramyxovidae family was first seen in an outbreak involving severe respiratory illness in pigs and encephalitic disease in humans in Kampung Sungai Nipah in Malaysia (1998) and later in Singapore in 1999.
NiV has been identified periodically in eastern India. Fruit bats of the Pteropodidae family are the natural host for NiV. It can be transmitted from animals (bats and pigs) to humans and can be transmitted from human-to-human.
Initial signs and symptoms of NiV infection are non-specific. In human, it may cause asymptomatic infection, acute respiratory infection and fatal encephalitis. People infected with NiV develop influenza-like symptoms of fever, headaches, myalgia, vomiting and sore throat. Severe cases might progress to encephalitis and seizures to come within 24-48 hrs. The typical incubation period lasts for 4-14 days, incubation periods as long as 45 days have been reported earlier.
Although many patients make full recovery but up to 20% may show long-term residual neurologic disorders (including seizures and personality disorders). Relapse or relayed onset encephalitis may be seen in a small fraction of patients.
Currently, there are no drugs or vaccines available for NiV infection. Case fatalities are estimated at 40-75% depending on the surveillance and subsequent management.
NiV infection can be prevented by avoiding exposure to sick pigs and bats in endemic areas. Risk of human to human transmission can be reduced by avoiding close contact with the infected people. Avoidance of contact and droplet precautions in addition to standard measures are recommended for healthcare settings. If an outbreak is suspected, the animal premises should be quarantined immediately. Culling of infected animals – with close supervision of burial or incineration of carcasses may be necessary to reduce the risk of transmission to people. Restricting or banning the movement of animals from infected farms to other areas can reduce the spread of the disease.
In the absence of a licensed vaccine, the only way to reduce infection in people is by raising awareness of the risk factors and educating people about the measures they can take to reduce exposure to and decrease infection from NiV.
Public health education messages should focus on the following:
- Reducing the risk of bat-to-human transmission
- Reducing the risk of animal-to-human transmission
- Reducing the risk of human-to-human transmission
The southern state of Kerala is currently experiencing an outbreak of Nipah virus which has claimed nearly 10 lives in the past 2 weeks.
Key facts summarised regarding the virus:
- Nipah virus is an RNA virus that is part of the Paramyxovidae family that was first identified as a zoonotic pathogen after an outbreak involving severe respiratory illness in pigs and encephalitic disease in humans in Malaysia and Singapore in 1998 and 1999.
- Nipah virus can cause a range of mild to severe disease in domestic animals such as pigs.
- Nipah virus infection in humans causes a range of clinical presentations, from asymptomatic infection (subclinical) to acute respiratory infection and fatal encephalitis.
- Nipah virus can be transmitted to humans from animals (bats, pigs), and can also be transmitted directly from human-to-human.
- Fruit bats of the Pteropodidae family are the natural host of Nipah virus.
- There is no treatment or vaccine available for either people or animals. The primary treatment for humans is supportive care.
- Nipah virus is on the WHO list of Blueprint priority diseases.
For more reference log on to: