Decoding the deadly Nipah virus

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Nipah

  • A virus named after Kampung Sungai Nipah, a village in Malaysia, where it was first discovered in 1998-99. The virus, that eventually killed 105 people in Malaysia, was first suspected to be Japanese encephalitis (JE) which, like the Nipah virus, induces brain inflammation. 
  • The virus, which was traced back to the pigs, led to a large-scale culling of the animals in this region. Further studies indicated that the initial transmission from bats to pigs probably occurred, when pig feed was contaminated with bat excretions, says a 2007 paper, titled ‘Lessons from the Nipah virus outbreak in Malaysia.

Zoonosis

  • According to the World Health Organization (WHO), “A zoonosis is any disease transmitted from vertebrate animals to humans.” It could be caused by a virus, bacteria, fungi or parasite; some examples include anthrax, bird flu, ebola, dengue, rabies, malaria, swine flu and leptospirosis.
  • Nipah is believed to be transmitted from what are called flying foxes, or mega bats, so called because they are the largest bat species. They eat fruits and live in trees. These are a part of the old-world fruit bat family, called pteropid bats. Bats often end up being reservoirs for a number of severe infectious diseases, including Ebola, SARS coronavirus, Nipah and Hendra.

Transmission

  • In the case of Nipah, disease transmission or the means by which a pathogen can be passed from one organism to another, is believed to take place, “when one consumes infected fruits and fresh date palm sap contaminated by bats.
  • Human-to-human transmission occurs due to direct contact.

RNA virus

  • Nipah is an RNA or Ribonucleic Acid virus.
  • RNA viruses are the most common cause of emerging diseases in humans, attributable to the high mutation rate in RNA viruses compared to DNA viruses.
  • Nipah belongs to a genus (category, in layperson speak) called the Henipavirus; the Hendra virus, also found on pteropid bats, belongs to this category too.
  • According to the CDC, “Transmission of HeV to humans has been invariably associated with close contact with ill horses, and transmission of NiV in Bangladesh is mainly through date palm sap contaminated with bat secretions.”

Biosafety Level 4

  • The virus, which is classified as Biosafety Level 4, meaning that it is highly infectious and needs a maximum containment facility, can be confirmed by an ELISA, RT-PCR or Serum Neutralization Test.
  • The incubation period is anywhere between 5-14 days, but it can soon affect the respiratory and nervous system and patients can go into delirium or coma.
  • Unfortunately, there is no definite treatment, except intensive supported care.
  • We need to maintain the vital functions.

Source:TH