Nipah virus in Asia: mapping spillover and transmission dynamics for effective control – a systematic review

Nipah virus (NiV) is a significant public health issue because of its high fatality rate and frequent outbreaks. This systematic review synthesizes key spillover and transmission patterns and evaluates ecological management strategies to inform priority interventions and resource allocation.
Following PRISMA guidelines, we searched multiple electronic databases, including PubMed, Embase, and Scopus. Study selection, data extraction, and quality assessment were done by three independent reviewers, with a fourth reviewer resolving any disagreements.
Close contact with NiV patients, especially during household caregiving and in healthcare settings, drove human-to-human transmission, while consumption of raw date-palm sap was a major spillover pathway. Outbreak contexts differed: pig-amplified spillover in Malaysia; recurrent seasonal bat-to-human spillover in Bangladesh linked to sap; and sporadic outbreaks in India associated with suspected exposure to bat-contaminated fruits or environments, with secondary transmission mainly in households and healthcare settings. Bamboo sap skirts reduce, but do not eliminate, bat contamination of sap, supporting their use as a risk-reducing ecological intervention.
Studies have reported various transmission and spillover pathways; however, data on exact modes and pathways remain scarce. Management strategies must also report feasibility and acceptability, and greater emphasis is needed on ecological management practices.
https://www.crd.york.ac.uk/prospero identifier is CRD42024546848.
Nipah virus is a deadly infection that spreads from animals, primarily fruit bats, to humans. It can also spread between people and has caused outbreaks in Asian countries, especially Bangladesh, India, and Malaysia. Since there is no licensed cure or vaccine, prevention is the best way to save lives. This review examines how the virus spreads, why outbreaks occur, and what measures can be taken to prevent them. We analysed 28 research papers published between 2000 and 2023. The findings show that many infections happen after drinking raw date palm sap contaminated by bats or through close contact with infected patients. Covering sap collection pots with bamboo skirts reduces contamination but does not entirely prevent it. Community education campaigns improved awareness and encouraged safer practices. In hospitals, the use of protective equipment and enhanced infection control measures reduced the risk of virus transmission. Surveillance systems helped detect outbreaks early and improve responses. However, each strategy faces challenges, including limited resources, changing community habits, and poor access to healthcare facilities and services in remote areas. Overall, no single solution is enough. A combined approach involving communities, hospitals, and governments is crucial for controlling Nipah virus outbreaks.