Written By: Satata Karmakar | Published : January 28, 2026 3:40 PM IST
Medically Verified By: Dr. Bharath Kumar Surisetti
Nipah Virus Explained: What Happens Inside the Body After It Enters the Bloodstream; How It Attacks the Brain
Nipah Virus In India: The year 2019 - one of the deadliest in modern history, the world witnessed the emergence of SARS-CoV-2, the virus responsible for COVID-19. The lethal virus outbreak was declared a pandemic after it infected millions of people worldwide - triggering severe health issues, including drop in blood oxygen levels, loss of smell and taste, and in rare cases, severe pneumonia signs. After battling this infection for over 7 years, the world is now eyeing towards the rise of another - comparatively more dangerous virus - Nipah, or NiV.
According to the latest updates, West Bengal has reported a sudden re-emergence of the deadly virus - after a record of 19 years. With a fatality rate ranging between 40-70%, the virus poses serious health threats, including permanent brain damage, organ failure, and, in the worst cases, death.
Although the risk of the virus spreading within the human community is low due to its inability to transmit from human-to-human, experts have still urged everyone to understand the current threat, take proper precautions, and follow safety measures to prevent the virus from triggering another pandemic.
Nipah is a zoonotic virus, which means it can spread from animals to humans. It can also spread directly between humans or through contaminated food. Symptoms of the virus range from mild to asymptomatic infections, to acute respiratory illness and fatal brain inflammation. Fruit bats are natural hosts of the virus. There have also been reports of the virus infecting other animals, such as pigs, cats, goats, horses and sheep. Infectious diseases expert Leong Hoe Nam said the disease can spread from animals to humans through direct contact with an infected host animal and its fluids.
What is the history of the nipah virus? In 1999, Nipah was first discovered following an outbreak in pigs and people in Malaysia and Singapore. Three hundred people got sick and more than one hundred of those people died. In this first outbreak, bats initially spread the Nipah virus to pigs. People who worked closely with the infected pigs got sick, as well.
Nipah outbreaks have only been reported from Bangladesh, India, Malaysia, Philippines, and Singapore. However, the fruit bats that carry the Nipah virus are found throughout Asia, the South Pacific, and Australia.
Nipah virus (NiV), a highly pathogenic RNA virus, initially establishes infection through replication in the epithelial cells of the upper respiratory tract. Following local replication, the virus enters the bloodstream (viremia), enabling systemic dissemination to multiple organ systems, including the cardiovascular system, lungs, and kidneys. A hallmark of NiV pathogenesis is its pronounced endotheliotropism its affinity for endothelial cells which results in widespread vasculitis and vascular damage. This endothelial injury increases vascular permeability, facilitating viral invasion across the blood-brain barrier.
In an exclusive interaction with TheHealthSite.com, Dr. Bharath Kumar Surisetti, Consultant Neurologist, Yashoda Hospitals, Hyderabad, says - : "Humans contract the Nipah virus when it enters through their respiratory system or when they consume infected food. The virus first infects cells in the mouth, throat, or lungs, where it begins to replicate. Nipah virus uses its surface proteins to bind with ephrin-B2 and ephrin-B3 receptors which exist throughout human cells but are found in highest concentration on blood vessel lining cells. After the virus completes its initial replication process, it starts spreading through the bloodstream which enables its distribution throughout various body parts."
Nipah virus exhibits high preference for endothelial cells which constitute the blood vessel inner lining. The infection of these cells results in inflammation which causes vasculitis and leads to blood vessel destruction and organ damage that includes the lungs and kidneys and spleen. The condition can cause serious breathing problems in the lungs.
The most dangerous phase occurs when the virus reaches the brain. Nipah virus can enter the blood-brain barrier because it breaks down blood vessels and moves inside infected immune cells and travels through nerves that extend from the nasal cavity. The virus enters the brain and triggers encephalitis which causes severe brain tissue inflammation. The condition leads to tissue swelling, which blocks blood circulation and causes direct damage to neurons.
"The brain involvement in this condition leads to symptoms which include headache, confusion, seizures, coma, and death which occurs frequently. The survivors will develop lasting neurological issues while experiencing brain inflammation that returns after an extended period of time," said Dr. Bharath Kumar Surisetti.
Early-stage infection may present non-specific symptoms such as fever, headache, myalgia, and respiratory discomfort, which can delay diagnosis. Given its rapid progression, high case-fatality rate (ranging from 40 75%), and potential for nosocomial transmission, NiV infection is classified as a BSL-4-level medical emergency. Management requires immediate isolation, intensive critical care, and continuous neurological monitoring, with supportive therapy being the mainstay, as no specific antiviral or vaccine is currently approved.
What is the virus' incubation period? According to the experts, individuals infected with the Nipah virus usually start showing the symptoms within 4-14 days after contracting the virus.
Talking about the time an infected patient usually takes to recover from the infection, CDC states - "People with Nipah are typically sick for 3 to 14 days with fever, headache, cough, sore throat, and difficulty breathing. Later in the infection, some people may experience brain swelling, or encephalitis, where severe symptoms can include confusion, drowsiness, and seizures. People with these symptoms can fall into a coma within 24-48 hours".
As cases of this highly dangerous virus - with no vaccines - is being detected in India, here are some simple tips that one needs to follow right now to stay safe from the infection:
"Preventive measures (hand hygiene, careful washing of fruits and avoidance with sick people) are key. Staff should take strict infection control precautions."
As of now, the data doesn't support anything so serious. However, since the virus doesn't have any vaccines that can help protect an individual from contracting or developing the symptoms, experts say that following safety protocols is important.
We should never take viruses lightly, especially one that has a fatality rate ranging between 40-75%. Also, the virus has been found transmiting from one person to another. According to the World Health Organisation (WHO) - While Nipah does not transmit easily via casual contact, it can spread through direct contact. Yes, you read that right! Just like the COVID virus, Nipah also spreads via bodily fluids. including saliva, urine, blood, and respiratory secretions.
Well, that being said, experts have asked everyone to be cautious but not 'panic'. Stay aware, stay alert, and stay safe! Follow official websites to stay updated with all the recent news updates on nipah virus outbreak in India, 2026.
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