Nipah Virus Returns to West Bengal: Symptoms & Diagnosis

West Bengal health authorities have gone on alert after two healthcare workers (nurses) from a private hospital in Barasat, North 24 Parganas were reported as suspected Nipah virus cases. Early screening at ICMR’s VRDL lab at AIIMS Kalyani reportedly indicated Nipah positivity, and samples were sent for confirmation to the National Institute of Virology (NIV), Pune—the country’s key reference lab for such high-risk pathogens.

Officials said the two patients were in critical condition and placed under isolation care with ventilator support, while contact tracing was initiated across multiple districts linked to their movements and contacts.

Nipah is not new to the state: earlier outbreaks in West Bengal were reported in 2001 and 2007, and India has seen more recent clusters in Kerala in later years. That history is one reason why public health teams move quickly when suspected cases appear.

What is Nipah Virus, and How Does it Spread?

Nipah virus (NiV) is a zoonotic infection—meaning it can spread from animals to humans. Fruit bats are widely recognized as natural hosts, and transmission can also occur through close contact with an infected person’s body fluids or contaminated materials in care settings.

Because human-to-human spread is possible—especially among caregivers and in hospitals—health departments typically emphasize rapid isolation, contact tracing, and strict infection control when Nipah is suspected.

Symptoms of Nipah Virus Infection

Nipah virus illness often begins with flu-like symptoms, but can rapidly escalate to severe neurologic and respiratory disease.

Early / Initial Symptoms

Symptoms usually appear 4–14 days after exposure (sometimes reported longer) and may include:

Fever
Headache
Muscle pain
Sore throat, cough
Breathing difficulty or shortness of breath
Vomiting or diarrhea in some cases

These can resemble many viral illnesses, so exposure history and risk context matter greatly.

Warning signs / severe disease (needs urgent care)

Drowsiness, confusion, altered consciousness
Seizures
Signs of encephalitis (brain inflammation)
Severe cases can deteriorate quickly, with encephalitis progressing rapidly in some patients.

Long-term/after-effects

Survivors can have lasting neurological problems such as cognitive impairment, seizures or personality changes.

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Diagnosis: How Nipah Infection is Confirmed

Because early symptoms are non-specific, lab testing is essential.

📌 Clinical Suspicion + Exposure History

Doctors suspect Nipah when someone has fever and severe symptoms plus known risk factors, such as:

Exposure to infected bats or animals
Close contact with a known or suspected human case
Travel to or residence in areas with outbreaks

🧪 Laboratory Confirmation

Confirmed diagnosis typically requires:

Real-time RT–PCR to detect Nipah viral genetic material (gold standard during acute infection).
Serologic tests (IgM/IgG ELISA) to detect immune response (may support diagnosis in appropriate phases).
Samples (e.g., throat swab, blood, urine) must be processed under strict safety conditions due to the virus’s infectivity.

⚠️ No Routine Rapid Test

There is no widely available rapid point-of-care test, meaning early suspicion and specialist lab confirmation are crucial.

In the current West Bengal situation, initial detection was reported at AIIMS Kalyani’s VRDL, with confirmation processes linked to NIV Pune as reported by multiple outlets.

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Safety Measures: What People in West Bengal Should Do Now

Health advisories generally aim to reduce exposure risk without creating panic. Practical steps include:

For everyone

Wash hands regularly with soap and water.
Avoid consuming fruit that may be contaminated (wash/peel; discard partially eaten fruit).
Avoid areas where bats roost and avoid contact with bat droppings or secretions.
If you develop fever with severe headache, breathing trouble, confusion, or seizures—seek medical care promptly and mention any exposure/contact history.

For caregivers at home

Avoid direct contact with the sick person’s saliva, urine, vomit, and contaminated linens.
Use masking and strict hand hygiene, and clean/disinfect frequently touched surfaces.
Follow local health teams if they advise monitoring/quarantine for close contacts.

For hospitals and healthcare workers

Emphasize standard + droplet + airborne precautions, especially during aerosol-generating procedures.
Ensure isolation, PPE compliance, and active monitoring of exposed staff.
Maintain meticulous contact tracing and quarantine protocols for high-risk contacts.

Nipah Virus: Fatality / Death Rate

The case fatality rate (death rate) for Nipah virus infection is very high compared with many infectious diseases:

Typically estimated between ~40 % and 55 % of people with confirmed infection may die from the disease. This range varies by outbreak, healthcare access, and surveillance quality.
Some outbreaks in Bangladesh historically had fatality as high as over 70 %.
In India (e.g., Kerala), previous outbreaks also showed very high death rates, and severe cases can progress rapidly without effective antiviral treatment.

This high fatality is one reason public health authorities take even suspected cases extremely seriously.

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Why This Alert is Taken Seriously

Public health agencies treat suspected Nipah cases as high priority because the infection can be severe, outbreaks can amplify through close contact, and outbreak control depends heavily on early detection, rapid isolation, and strict infection control.

At the same time, it’s important to track what’s confirmed vs suspected—and in this episode, multiple reports emphasize that confirmation from reference testing is a key next step.

Key Highlights

✔️ Nipah is a highly lethal virus with death rates often between 40 % and 55 %, and in some outbreaks even higher.
✔️ Initial symptoms are non-specific, like flu, but can quickly progress to dangerous neurological and respiratory conditions.
✔️ Early recognition based on symptoms + exposure history and lab confirmation are vital.
✔️ There is no specific cure or vaccine approved, so prevention, hygiene, and early medical care are central to safety.

References: India Today, NDTV, The Hindu

Nipah Virus Returns to West Bengal: Symptoms, Death Rate & Safety Measures Explained

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