Nipah Virus: The Indian state of Kerala has reported two deaths caused by the Nipah virus, as of September 12, 2023. One of them died in September, while the other died on August 30, 2023, an official from the National Institute of Virology has said, news agency Reuters reported. Since two more people from the family of one of the people who died from Nipah virus in Kerala were suspected to have been infected with the virus, and hence, their samples have been sent for testing, and their report has been sent to the Union health ministry.
The Nipah virus strain which caused these deaths in Kerala is the Bangladesh variant, State Health Minister Veena George has said. This variant was first identified in Bangladesh in 2001.
What is the Nipah virus?
Nipah virus is a zoonotic virus that was discovered in 1999 after an outbreak of disease from the pathogen occurred in pigs and people in Malaysia and Singapore. About 300 people were infected with the virus, and more than 100 people died.
The year 1999 was the last time a Nipah virus outbreak occurred in Malaysia and Singapore. Some regions of Asia, such as India and Bangladesh, have recorded Nipah virus outbreaks almost annually. Since the Nipah virus was found to spread from one human to another in these outbreaks, scientists are worried that the pathogen may lead to a global pandemic some day.
The fact that the Nipah virus is zoonotic means that it can be transmitted between animals and humans. Fruit bats or flying boxes are the natural reservoir of the Nipah virus.
If a person is infected with the Nipah virus, they can suffer from encephalitis, or swelling of the brain. People living in or visiting areas where the Nipah virus is present just avoid exposure to sick pigs and bats in the region, and avoid drinking raw date palm sap which is likely to be contaminated by an infected bat, in order to prevent Nipah virus infection.
Standard infection control practices such as sanitisation can help prevent transmission of the Nipah virus from one person to another.
According to the Centers for Disease Control and Prevention (CDC), the Nipah virus belongs to a family called Paramyxoviridae, and the genus Henipavirus. The fruit bat, or flying fox, which serves as the natural reservoir of the Nipah virus, belongs to the genus Pteropus.
Animals such as pigs can also be infected with the Nipah virus.
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How is the Nipah virus transmitted?
The Nipah virus can be spread to people through direct contact with infected animals such as bats or pigs, or by coming in contact with the body fluids of infected animals. The pathogen also spreads to people when they come in close contact with infected humans. Consumption of palm sap or fruit contaminated by a bat infected with the Nipah virus can also cause Nipah virus infection. If one climbs trees where flying foxes reside, they may contract Nipah virus infection.
The first known Nipah virus outbreak probably occurred due to close contact between humans and pigs, which were infected by bats.
Person-to-person transmission of the Nipah virus is not regularly reported in Bangladesh and India, and is mostly seen in the families of infected people.
Why is there an outbreak of the Nipah virus in Kerala?
The outbreak of the Nipah virus in Kerala is probably due to human interaction with infected animals, or with fruit bats.
“The outbreak in Kerala could be due to factors such as fruit bats as natural hosts and human interactions with infected animals,” Dr Shuchin Bajaj, Founder Director, Ujala Cygnus Group of Hospitals, told ABP Live.
Will the Nipah virus spread to other Indian states?
According to Dr Bajaj, the Nipah virus may spread to other Indian states if preventive measures are not implemented. He said that containment measures can prevent widespread transmission of the Nipah virus to other states.
How fast does the Nipah virus spread?
The Nipah virus spreads slower than SARS-CoV-2. However, it is not as contagious as the influenza virus.
“ The Nipah virus can spread relatively quickly within close contact, but it is not as contagious as some other viruses like the influenza virus,” said Dr Bajaj.
Why is the Nipah virus dangerous despite the fact that it does not spread fast?
The Nipah virus is dangerous, despite the fact that it does not spread fast. This is because it has a high mortality rate, and there exists no specific treatment for or vaccine against Nipah virus infection, according to Dr Bajaj.
How can one know if they are infected with the Nipah virus, by observing their signs and symptoms?
The Nipah virus may cause mild fever, or severe illness. In some cases, Nipah virus infection can be fatal.
It takes the symptoms of Nipah virus infection to appear about four to 14 days after exposure to the virus. In the first three to 14 days, the infected person suffers from fever and headache, and shows signs of respiratory illness such as cough, difficulty breathing, and sore throat.
After this, the person may suffer from brain swelling or encephalitis. When brain swelling occurs, symptoms such as drowsiness, mental confusion, and disorientation start showing up. If not treated, the person may go into a coma.
In 40 to 70 per cent of the cases of Nipah virus infection, deaths may occur.
Even after the Nipah virus infection is healed, the person may suffer from long-term side effects such as convulsions and personality changes.
In some cases, deaths have been reported months or years after exposure to the Nipah virus. Such infections are known as dormant or latent infections.
Therefore, if one has fever, suffers from a headache, and feels drowsy, and lives in an area where Nipah cases are on the rise, they must get themselves tested for infection with the pathogen.
How is Nipah virus infection diagnosed?
Different tests which can diagnose Nipah virus infection include laboratory tests such as polymerase chain reactions. These are effective during the early stages of the illness, and are performed on throat and nasal swabs, urine, blood, and the cerebrospinal fluid.
During later stages of the illness, or after recovery, enzyme-linked immunosorbent assay is performed to detect antibodies against the Nipah virus.
Since the virus does not result in symptoms specific to the pathogen, it is quite difficult to diagnose illness caused by it at early stages of the infection.
How can Nipah virus infection be treated?
No licensed treatments for Nipah virus infection are available. A person who suffers from Nipah virus infection is mostly given supportive care, which includes rest, hydration, and treatment of symptoms.
“There is no specific antiviral treatment, so supportive care in a hospital is crucial for Nipah virus patients,” said Dr Bajaj.
However, some monoclonal antibody therapies, which are under development and evaluation, may help treat Nipah virus infection in the future.
How can one prevent Nipah virus infection?
Nipah virus infection can be prevented by washing hands regularly, avoiding areas where bats roost, avoiding contact with infected people and sick pigs or bats, and avoiding the consumption of products that could be contaminated with the blood or urine of flying foxes.
“Preventive measures include avoiding close contact with infected individuals and not consuming raw date palm sap,” said Dr Bajaj.
How does the Nipah virus affect the health of children?
Children infected with the Nipah virus are likely to suffer from more severe complications than adults because their immune systems are still developing.
“Children can be vulnerable to the Nipah virus, experiencing symptoms similar to adults. However, they may face a higher risk of severe complications due to their developing immune systems. Timely medical attention is crucial for children infected with Nipah,” said Dr Bajaj.
Who is at the greatest risk of infection with the Nipah virus?
Healthcare workers, who are in close contact with patients infected with the Nipah virus, are some of the people at the highest risk of Nipah virus infection. Other people who are in close contact with infected animals or individuals are also at a high risk of infection, said Dr Bajaj. “Additionally, individuals living in or near areas with fruit bat populations, which can carry the virus, are at greater risk of exposure.”