Nipah Virus (NIV)

In Context 

• A case of the Nipah virus infection was reported in the Kozhikode district of Kerala after a gap of over three years.

About Nipah Virus (NIV)

• It is a zoonotic virus (it is transmitted from animals to humans) .
• The organism which causes Nipah Virus encephalitis is an RNA or Ribonucleic acid virus of the family Paramyxoviridae, genus Henipavirus, and is closely related to Hendra virus.
• The case fatality rate is estimated at 40% to 75%. This rate can vary by outbreak depending on local capabilities for epidemiological surveillance and clinical management.
• The virus can also cause severe disease in animals such as pigs, resulting in significant economic losses for farmers.  

Past Outbreaks 

• Nipah virus was first recognized in 1999 during an outbreak among pig farmers in Malaysia when pigs in Malaysian farms came in contact with the bats who had lost their habitats due to deforestation.
• It was also recognized in Bangladesh in 2001, and nearly annual outbreaks have occurred in that country since.
•  The disease has also been identified periodically in eastern India.
  • In subsequent outbreaks in Bangladesh and India, consumption of fruits or fruit products (such as raw date palm juice) contaminated with urine or saliva from infected fruit bats was the most likely source of infection.

Transmission

• The disease spreads through fruit bats or ‘flying foxes,’ of the genus Pteropus, who are natural reservoir hosts of the Nipah and Hendra viruses. 
• The virus is present in bat urine and potentially, bat faeces, saliva, and birthing fluids. 
• The virus is transmitted to people from animals and can also be passed on through contaminated food or directly from person to person. 
  • Human-to-human transmission of the Nipah virus has also been reported among family and caregivers of infected patients.

   Image Courtesy: TOI

Symptoms:

•  In infected people, it causes a range of illnesses from asymptomatic (subclinical) infection to acute respiratory illness and fatal encephalitis. 

Treatment:

• There are currently no drugs or vaccines specific for Nipah virus infection although WHO has identified Nipah as a priority disease for the WHO Research and Development Blueprint.  
• Intensive supportive care is recommended to treat severe respiratory and neurologic complications.

Preventive Measures: 

• Raising awareness: In the absence of a vaccine, the only way to reduce or prevent infection in people is by raising awareness of the risk factors and educating people about the measures they can take to reduce exposure to the Nipah virus.
• Reducing the risk of bat-to-human transmission: Efforts to prevent transmission should first focus on decreasing bat access to date palm sap and other fresh food products. 

• Reducing the risk of animal-to-human transmission: Gloves and other protective clothing should be worn while handling sick animals or their tissues, and during slaughtering and culling procedures. 

• Reducing the risk of human-to-human transmission: Close unprotected physical contact with Nipah virus-infected people should be avoided. Regular hand washing should be carried out after caring for or visiting sick people

• WHO response:
  • WHO is supporting affected and at-risk countries with technical guidance on how to manage outbreaks of the Nipah virus and on how to prevent their occurrence.
  • The risk of international transmission via fruits or fruit products (such as raw date palm juice) contaminated with urine or saliva from infected fruit bats can be prevented by washing them thoroughly and peeling them before consumption. Fruit with signs of bat bites should be discarded.

Source: TH