Head of the Virology Department at National Institute of Laboratory Medicine and Referral Center, Dr. Arifa Akram Borna. Photo : BSS

By Borun Kumar Dash

DHAKA, Jan 11, 2026 (BSS)- Although raw date palm sap is considered the primary source of Nipah virus, the zoonotic virus can also be transmitted by consuming any half-eaten fruit contaminated with saliva or urine of bats. 

Recent research showed that Nipah virus can be transmitted to infants through the breast milk of infected mothers.

Therefore, everyone must refrain from consuming raw date palm sap and any half-eaten fruit contaminated with bat saliva or urine. 

If a mother is infected with Nipah virus and has a minor child, breastfeeding should be stopped. Every year, people in the countryside organize raw date palm juice consuming festival, which is one of the main sources of the virus contamination. 

Dr. Arifa Akram Barna, head of the Virology Department at National Institute of Laboratory Medicine and Referral Center said the government should officially prohibit such festivity.

If preventive measures are taken, Nipah virus transmission can be controlled to a great extent, she said in while talking to BSS on Nipah virus transmission and public awareness.

Dr Barna said prevalence of Nipah Virus is high in Bangladesh and India. The virus mainly enters into the human body through consumption of fruits or fruit products (such as raw date palm sap, jujube (boroi) and guava which are contaminated with the urine or saliva of bats.
 
Later, the virus spreads from infected individuals to others through close contact, leading to an increase in the number of patients.

She said evidence has been found that the disease also spreads through contact with infected persons. People can also become infected by eating half-eaten jujube-type fruits that bats partially consume and leave behind the rest. In Bangladesh, cases of the virus are usually reported during winter (December to April).

Dr Barna said the virus can be diagnosed by testing samples such as urine, blood and cerebrospinal fluid using PCR, ELISA and Culture methods. As Nipah virus is a highly lethal pathogen, testing is conducted in Biosafety Level-4 laboratories. However, if samples are inactivated during collection, testing can be carried out cautiously in Biosafety Level-2 laboratories.

She said, according to World Health Organization the fatality rate of Nipah virus infection ranges from 40 to 75 percent. Symptoms usually appear within 4 to 14 days after the virus enters the human body, though the virus can remain latent for up to 45 days without symptoms, she added.
 
She said initially, most patients seek medical care with symptoms such as fever, headache, muscle pain, vomiting, sore throat or flu-like illness. 

But very quickly, dizziness, excessive thirst, loss of consciousness, abnormal behavior, severe neurological symptoms due to acute brain infection, and respiratory problems develop and most of the patients succumb to the disease. Though a small number of patients initially recover but later they may suffer from brain infections, she noted.

Dr Barna said the virus spreads from animals to humans and the infected individuals may range from being completely asymptomatic to developing severe encephalitis.

Highlighting the history of Nipah virus, she said the disease was first identified among pig farmers in Malaysia and Singapore in 1998–99.  At that time, 109 out of 283 infected individuals died. 

In Bangladesh, the disease was first detected in Meherpur in 2001, and laboratory confirmation was made in 2004. Since then, Nipah virus cases have been reported almost every year in the country. So far (2001–25), 343 Nipah virus cases have been identified in 32 districts of Bangladesh.

Meherpur, Faridpur, Rajshahi, Naogaon, Rangpur, Pabna and Natore districts were recorded with higher prevalence of the virus. 

Among them, 245 people have died, indicating a mortality rate of 71 percent. The highest number of cases has been reported in Faridpur, followed by Rajbari.

Regarding the spread of the virus in neighboring India, Dr Barna said India has so far experienced three Nipah outbreaks at Siliguri in 2001, Nadia in 2007 and Kerala in 2018, killing 45 patients out of 66 infected. 

In Siliguri, transmission occurred mainly through healthcare-related exposure. About 75 percent of infected individuals there were hospital staff, patients or attendants. All patients identified in India in 2024 and 2025 died, she said.

Stressing the responsibilities of the government and the general public in preventing Nipah virus, she said people must be made aware of the virus through media campaigns, posters and leaflets.

Raw or unclean date palm sap should not be consumed, she said adding however, processed molasses (gur) is safe to eat.

Dr Barna also said hospitals and health centers must have facilities for Nipah detection and treatment, and healthcare workers should be trained. 

Regular health surveillance should be conducted in high-risk areas. In case of an outbreak, urgent isolation and contact tracing must be ensured, she said. 

Public awareness should be maintained, contact with sick individuals or animals should be avoided, and medical advice should be sought if suspicious symptoms appear, she added.

She also advised taking special precautions or wearing masks when visiting infected patients for care giving or emergency needs. 

Hand washing, mask use and maintaining social distance are essential. Those who come into contact with suspected patients should maintain self-isolation,” she suggests. 

Dr Barna said as no vaccine for Nipah virus has yet been discovered, awareness and prevention are the remedies to be protected.