Nipah virus infection
Zoonotic virus causing severe encephalitis and respiratory illness.
Nipah virus infection is a zoonotic viral disease caused by the Nipah virus (NiV), an RNA virus in the genus Henipavirus that normally circulates among fruit bats of the genus Pteropus. The disease was first identified in 1998 by researchers at the Faculty of Medicine, University of Malaya during an outbreak in Malaysia, and is named after the village of Sungai Nipah in Malaysia. Human contraction can range from asymptomatic infection to influenza-like illness or fatal encephalitis, with a case fatality rate estimated between 40% and 75%.
- First identified
- 1998
- Location of first outbreak
- Malaysia
- Pathogen type
- RNA virus (genus Henipavirus)
- Primary reservoir
- Fruit bats (genus Pteropus)
- Case fatality rate
- 40% to 75%
- Transmission modes
- Direct contact with infected animals or humans; short-range respiratory droplets; contaminated fomites
Quick Facts
- Symptoms
- Fever, headache, myalgia, vomiting, cough, sore throat, difficulty breathing, dizziness, drowsiness, altered consciousness
- Complications
- Encephalitis, seizures, acute respiratory distress, coma
- Onset
- 4 to 14 days after exposure
- Causes
- Nipah virus (spread by direct contact)
- Diagnosis
- Based on symptoms, confirmed by laboratory testing
- Prevention
- Avoiding exposure to bats and to sick pigs and people.
- Treatment
- Supportive care only
- Prognosis
- 40–75% case fatality rate
- Frequency
- ~701 human cases (1998 to May 2018)
Facts from the source article.
Lore & Background
Nipah virus infection was first recognized in 1998 during an outbreak in Malaysia, where the majority of diagnosed patients were referred to and treated at the University of Malaya Medical Centre. The disease is named after the village Sungai Nipah in Malaysia. Pigs were also infected, and millions were culled by Malaysian authorities in 1999 to stop the spread. The initial case in human outbreaks has always been zoonotic, from exposure to contaminated secretions or tissues of infected bats or pigs. Subsequent human-to-human transmission occurs via close contact with infected persons or exposure to infected body fluids such as blood, urine, and nasal secretions. Most experts do not classify the virus as airborne, though short-range exposure to respiratory droplets in close contact settings can transmit it. Indirect transmission via contaminated fomites is also likely responsible for many cases.
Reader's Guide
Nipah virus infection remains a significant public health concern due to its high mortality rate (40–75%) and potential for person-to-person transmission. Outbreaks have been reported in Malaysia, Singapore, Bangladesh, and India, with the highest mortality seen in Bangladesh. The disease can cause severe encephalitis, leading to coma within 24 to 48 hours, and survivors often suffer long-term neurological consequences such as memory loss, impaired cognition, seizures, and personality changes. The virus can also persist and reactivate months or years after initial infection. As of 2024, there is no specific treatment or vaccine, though a candidate vaccine (ChAdOx1 NipahB) commenced Phase I clinical trials in January 2024. Prevention relies on avoiding exposure to bats and infected animals, not drinking raw date palm sap, and using standard infection control practices in healthcare settings. The 1998–1999 Malaysian outbreak saw 265 human cases with 105 deaths, and subsequent outbreaks in Bangladesh and India have demonstrated the virus's ability to spread in hospital settings.
Did You Know?
- The disease is named after the village Sungai Nipah in Malaysia.
- The case fatality rate is estimated between 40% and 75%.
- Bats are known to drink toddy collected in open containers and occasionally urinate in it, contaminating it with the virus.
- In January 2024, a candidate vaccine, ChAdOx1 NipahB, commenced Phase I clinical trials.
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