Another outbreak of the Nipah virus in India has put Asian countries on high alert. This virus is particularly dangerous due to its high fatality rate, which ranges from 40% to 75% in humans. Following reported deaths in West Bengal, Thailand, Malaysia, and Singapore have introduced new screening measures.
Nipah belongs to the Henipavirus category. It is a zoonotic virus, meaning the disease is transmitted from animals to humans. The first major outbreak of this virus was recorded in Malaysia in 1998.
Transmission Routes
There are three primary ways the virus spreads:
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Direct contact with bats: Infection occurs through contact with the saliva, urine, or feces of an infected bat. Additionally, the virus can spread to humans from other animals, such as pigs, as was the case during the first outbreak.
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Consumption of contaminated food: Products from date palms, such as raw juice or syrup that may have been contaminated by bats, are particularly dangerous.
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Human-to-human transmission: This occurs through close contact with an infected individual, such as providing care in a family setting or a hospital. It is worth noting that this method of spread is relatively rare compared to other forms.
What defines “close contact” with an infected person?
In the case of the Nipah virus, close contact primarily refers to physical contact with a patient’s biological fluids. This includes direct care, such as bathing the patient, changing their clothes, or sharing a bed.
Since the virus exists in high concentrations in saliva and blood, any unprotected contact that facilitates these fluids reaching the mucous membranes (mouth, eyes) creates a high risk of infection.
Is the threat of a global pandemic real?
Theoretically, any virus can undergo mutation; however, in the case of Nipah, this is a much more complex process than it is for influenza or the coronavirus. Its genetic structure does not allow the virus to easily change its properties or rapidly adapt to new environments.
The transmission dynamics of the Nipah virus differ radically from COVID-19. While a person infected with the coronavirus could infect dozens of others simply by being in the same room, the transmission chain for Nipah is usually very short—an infected person, on average, infects fewer than one other person.
There is a significant biological barrier preventing its pandemic spread. Although Nipah is an RNA virus, it is not as flexible as COVID-19 in terms of airborne transmission. For it to pose a global threat, a radical mutation would be required to allow it to survive in the air for long periods and spread effectively through the upper respiratory tract.
Furthermore, the spread of the virus is limited by its own high mortality rate. For a pandemic to occur, the infected host must remain alive and mobile for a long time to transmit the virus to many people. Nipah, however, causes such rapid and severe illness that the patient quickly becomes incapacitated.
This factor naturally restricts the virus from reaching a broad scale, as an infected person is physically unable to maintain active social interactions. Consequently, local outbreaks are more common than large-scale epidemic chains.
