Explained : Nipah Virus

  • In the news: Nipah virus infection outbreak in Kozhikode district Kerala.
  • Background : Nipah virus infection gets its name from the village in Malaysia where the person from whom the virus was first isolated succumbed to the disease.
  • It is an emerging infectious zoonosis, that is, a disease transmitted from animals to humans that broke out in Malaysia and Singapore in 1998 and 1999. It first appeared in domestic pigs and has been found among several species of domestic animals including dogs, cats, goats, horses and sheep.
  • 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 virus has been listed in the World Organisation for Animal Health (OIE) Terrestrial Animal Health Code and must be reported to the OIE (OIE Terrestrial Animal Health Code).
  • 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.  In Bangladesh in 2004, humans became infected with NiV as a result of consuming date palm sap that had been contaminated by infected fruit bats.
  • In Bangladesh and India, there have been reports of possible human-to-human transmission of the disease.
  • Precautions Therefore, precautions are necessary for hospital workers in charge of taking care of the infected patients.Precautions should also be taken when submitting and handling laboratory samples, as well as in slaughterhouses.
  • Symptoms: human infection presents as an encephalitic syndrome marked by fever, headache, drowsiness, disorientation, mental confusion, coma, and potentially death. During the outbreak in Malaysia, up to 50 per cent of clinically apparent human cases died.
  • How do doctors diagnose Nipah ?  Serology- blood tests to see the antibodies, Histopathology- microscopic study of tissues, PCR- Polymerase Chain Reaction technique to look for viral DNA, Virus isolation Confirmatory tests include,Serum Neutralization Test, ELISA, RT-PCR.
  • The Nipah virus is classified as a biosecurity level (BSL) 4 agent and the tests should be carried out in special labs to prevent its spread.
  • Treatment: There is no specific treatment for Nipah Virus. The primary treatment for human cases is intensive supportive care.According to WHO, ribavarin can reduce the symptoms of nausea, vomiting, and convulsions associated with the disease. Individuals infected need to be hospitalised and isolated.

Prelims:

  1. Pteropus poliocephalus (Gray-headed Flying Fox, Grey-headed Flying-fox, Grey-headed Flying Fox) Red List Category & Criteria: Vulnerable
  2. The enzyme-linked immunosorbent assay (ELISA)  is a test that uses antibodies and color change to identify a substance. Link it to HIV anti-retroviral therapy (ART). There are two HIV tests: the ELISA detects infection, and viral load test, the HIV’s RNA in an infected person. Viral suppression (reducing viral load to an undetectable level) is the treatment goal.

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