icddr,b scientists discover mother-to-child Nipah antibody transfer

• Fatality rate due to the virus in Bangladesh 71%
• Many survivors suffer neurological issues
• Raw date palm sap prime medium for transmission
• A genus of bats contaminates the sap
• IEDCR warns against taking raw date palm sap even after careful collection
• About 331 cases reported in the country since 2001

Scientists of the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) have confirmed for the first time the transfer of humoral immunity against Nipah virus from a mother to her newborn.

The research paper in this regard has already been published in the journal Tropical Medicine and Infectious Disease, according to a press release by the centre on Tuesday.

According to the World Health Organisation, the mortality rate for Nipah virus infection is estimated at 40% to 75%, and in Bangladesh, it is about 71%. Those who survive suffer from severe neurological complications. Moreover, there is a high chance that these symptoms worsen progressively when a survivor becomes pregnant.

icddr,b said that in January 2020, a baby girl aged below five years and her mother from the Faridpur district were infected with Nipah virus. Both had a history of raw date palm sap consumption.

Unfortunately, the daughter passed away, and the mother survived with significant residual neurological impairment. She conceived again in November 2021 and received thorough antenatal follow-up services from the Institute of Epidemiology, Disease Control and Research. A healthy male baby was born in August 2022.

As part of the follow-up, specimens were collected and tested for Nipah virus infection eventually confirming transfer of humoral immunity from the mother to the baby.

Dr Syed Moinuddin Satter, the study's lead researcher and deputy project coordinator of Emerging Infections at icddr,b, said, "To the best of our knowledge, this finding is the first to report the vertical transfer of Nipah virus infection-specific immune properties. It warrants further exploration of its effectiveness in virus neutralisation and its potential to protect newborns. This will also be a reference for vaccine recommendations for pregnant and young women against the Nipah virus."

Dr Tahmeed Ahmed, executive director at icddr,b, appreciated the collaborative efforts and said, "icddr,b in partnership with the Government of Bangladesh, has been running the world's longest Nipah virus surveillance to detect Nipah Virus outbreaks, understanding the disease transmission, and finding new knowledge and insights that can help develop therapeutics and vaccines against this deadly infection. The effort has been rewarding, and I hope we will soon have effective preventive measures and treatments, and be able to save lives."

Nipah virus is transmitted from animals to humans chiefly through foods contaminated by animals. It can also spread between people. Fruit bats from the genus "Pteropus" are its natural reservoir. In Bangladesh, the virus was first reported in 2001, and since then infections by it have become endemic to this densely populated country. Until January 2023, a total of 331 cases were reported, with 236 fatalities or 71% mortality rate.

To warn people against consuming raw date palm sap, Professor Dr Tahmina Shirin, director of the Institute of Epidemiology, Disease Control and Research, has said, "Recently, we are observing a profound interest among people to consume raw date palm sap and also promote this practice through social media.  [However] Even if someone says they have taken precautions while collecting raw date palm sap, we would urge everyone not to take the drink because it is still unsafe."