Nipah Virus: signs, symptoms, infection

Nipah Virus Kerala

A boy infected with the Nipah virus has died in Kerala, a state already hit badly by Covid-19. How do the two viruses compare in transmissibility and fatality? How is Kerala addressing the twin concerns?

A 12-year-old boy infected with the Nipah virus died in a private hospital in Kozhikode on Sunday morning. The boy showed symptoms of encephalitis and myocarditis – inflammation of the brain and heart muscles respectively.

The re-emergence of the Nipah virus in Kerala poses a fresh risk in the state that is already struggling with the Covid-19 pandemic, contributing about 60% of all new cases in the country these days. However, this is not the first time that Nipah virus has been detected in Kerala, or elsewhere in India, and previous outbreaks have remained largely localised and have been contained relatively quickly.

What is the Nipah virus?

Nipah Virus ( NiV ) is a member of the family Paramyxoviridae, genus Henipavirus. It is a zoonotic virus, meaning that it initially spreads between animals and people. The animal host reservoir for NiV is the fruit bat (genus Pteropus), also known as the flying fox. Given that NiV is genetically related to Hendra virus, another henipavirus known to be carried by bats, bat species were quickly singled out for investigation and flying foxes were subsequently identified as the reservoir.

Scientific NameNipah Virus
Family Paramyxoviridae

Nipah Virus Signs And Symptoms

Symptoms may initially include one or several of the following:

  • Fever
  • Headache
  • Cough
  • Sore throat
  • Difficulty breathing
  • Vomiting

Severe symptoms may follow, such as:

  • Disorientation, drowsiness, or confusion
  • Seizures
  • Coma
  • Brain swelling (encephalitis)

Nipah Virus Origin

The first outbreaks of the Nipah virus among humans was reported from Malaysia (1998) and Singapore (1999). The virus takes its name from the village in Malaysia where the person in whom the virus was first isolated died of the disease.

Since it was first identified in 1998-99, there have been multiple outbreaks of the Nipah virus, all of them in South and Southeast Asian nations. In Bangladesh, there have been at least 10 outbreaks since 2001. In India, West Bengal had seen an outbreak in 2001 and 2007, while Kerala had reported several cases in 2018.

Cause of Nipah virus

Given that NiV is carried by bats, bat species were quickly singled out for investigation and flying foxes were subsequently identified as the reservoir. Infected fruit bats can spread the disease to people or other animals, such as pigs.

Nipah Virus Vacinee

The HeV-sG recombinant antigen as subunit vaccine for use in people against Nipah and Hendra virus infection and disease has been in preclinical development since 2012 and it is currently in clinical development as an emergency vaccine countermeasure for Nipah virus outbreaks

Nipah virus prevention

In areas where Nipah virus (NiV) outbreaks have occurred (Kerala ), people should:

  • Practice handwashing regularly with soap and water
  • Avoid contact with sick bats or pigs
  • Avoid areas where bats are known to roost
  • Avoid consumption of raw date palm sap
  • Avoid consumption of fruits that may be contaminated by bats
  • Avoid contact with the blood or body fluids of any person known to be infected with NiV

How does it spread?

It is a zoonotic virus, meaning it has been transmitted from animals to human beings. The transmission happens mainly through consumption of contaminated food. But human-to-human transmission is also considered possible. The animal host reservoir for this virus is known to be the fruit bat, commonly known as flying fox. Fruit bats are known to transmit this virus to other animals like pigs, and also dogs, cats, goats, horses and sheep.

Source : Myupchar

Humans get infected mainly through direct contact with these animals, or through consumption of food contaminated by saliva or urine of these infected animals. Person-to-person transmission is not fully established, but a recent study, published by two Bangladeshi researchers in March this year, said that previous outbreaks in Bangladesh, the Philippines and India suggested “that respiratory droplets of an infected person can transmit the virus”. During previous outbreaks, people in close contact with the infected person, mainly hospital staff and caregivers, have contracted the disease.

Does it spread as fast as Covid-19?

The Nipah virus is known to spread far more slowly than SARS-CoV-2. However, it is its ability to kill that is the biggest concern. During the first outbreak in Siliguri, 45 of the 66 people confirmed to have been infected died. That is a mortality rate of 68%. In the next outbreak, in Nadia district of West Bengal, in 2007, all the five infected people died.

During the most recent outbreak in Kerala in 2018, 17 of the 18 patients confirmed to have been infected died. In 2019, one case of Nipah virus infection was detected in Ernakulam, but prompt response restricted any further spread. The infected person survived.

In the Malaysian outbreak in 1999, a total of 265 people had been found infected, of whom 105 had died, according to a study, ‘Nipah Virus: Past Outbreaks and Future Containment’, by researchers from Cochin University of Science and Technology published in the April 2020 issue of the journal Viruses.

In comparison, the mortality rate of Covid-19 epidemic is expected to be around one per cent.

How well has Kerala handled previous Nipah outbreaks?

In 2018, Kerala had no past experience of handling a disease with such a high fatality rate. The state followed the protocol for Ebola virus disease which had been reported mainly in sub-Saharan Africa.

At one point in June 2018, around 3,000 people were under quarantine in Kozhikode and nearby Malappuram districts. All the persons who had direct or indirect contact with the suspected Nipah cases were thus put under observation.

When the state reported Nipah again in 2019, the health department already had a protocol in place to handle the situation. In 2019, only one case was reported in Ernakulam district.

How is Kerala handling the fresh Nipah concerns alongside Covid-19?

The Nipah virus victim hailed from the village of Chathamangalam, 50 km from Changaroth. Three wards under Chathamangalam panchayat in Kozhikode, where the victim lived, were completely closed down on Sunday morning. Micro-level restrictions have gone into effect.

Movement to and from these three wards have been banned. Police have put up barricades and checkpoints at all locations leading to the village of the victim.

With Covid-19 protocols already in place, there is heightened awareness about transmission of viral diseases. The ongoing use of PPE kits, gloves and masks, especially by healthcare workers and hospital staff, is likely to offer reduced opportunity for the transmission of the Nipah virus.

Should other states worry about Nipah spreading?

Thus far, all outbreaks of the Nipah virus have been localised and contained quickly, at least in comparison to the ongoing Covid-19 pandemic. The first outbreak in Malaysia started in September 1998, although it was only by March next year that scientists were able to confirm that this was a new virus they were dealing with. The outbreak was contained by May. In Bangladesh, where Nipah outbreaks have been the most recurrent, the transmissions have stopped after a couple of months.

One of the main reasons for a relatively quick end to an outbreak is the fact that Nipah virus is far less infective than SARS-CoV-2, for example. Human-to-human transmission is not as easy, or as fast, as seen in the case of SARS-CoV-2.

A study by Bangladeshi researchers P Devnath of Noakhali Science and Technology University and H M A A Masud of Chittagong University, published this year, noted that the reproductive number (R0) in the previous outbreaks of Nipah virus was about 0.48. The R-value is a measure of how quickly the virus spreads in the population. A value less than one means less than one person is being infected by an already infected person. In such a scenario, the outbreak is expected to diminish relatively quickly.

The study also notes that since Nipah outbreaks have happened mainly in sparsely populated villages, the potential of the virus to spread to many individuals has been low. Further, the very high death rates also contribute to low transmission.


When Nipah virus discovered?

In 1999

How did Nipah virus start?

Nipah virus (NiV) was first discovered in 1999 following an outbreak of disease in pigs and people in Malaysia and Singapore.

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