The Nipah virus (NiV) is a serious infectious disease that causes periodic outbreaks in parts of Asia. Although the risk to most people remains very low, understanding this virus is important if you plan to travel to one of the areas where it circulates. No cases have been found in the United Kingdom.
What is the Nipah virus?
The Nipah virus is a zoonotic virus, which means it can be transmitted from animals to humans. It can also be transmitted through contaminated food or directly from person to person. It was first identified in 1999 during an outbreak among pig farmers in Malaysia and Singapore.
The natural hosts of the virus are fruit bats, particularly those of the genus Pteropus. There is evidence that the Nipah virus can infect other animals, including pigs, dogs, cats, goats, horses, and sheep.
What are the symptoms?
The incubation period (the time between infection and the onset of symptoms) is typically 4 to 21 days, although longer periods have occasionally been observed.
Symptoms usually begin with the sudden onset of a non-specific flu-like illness or fever. Pneumonia and other respiratory problems can also develop.
The most serious complication is encephalitis (inflammation of the brain) or meningitis, which typically develops 3 to 21 days after the onset of the initial illness. This is the hallmark of Nipah infection and is associated with a very high mortality rate.
It is estimated that between 40 and 75% of people infected with the Nipah virus die. Some survivors may be left with permanent neurological difficulties, including persistent seizures and personality changes. In rare cases, the virus can reactivate months or even years after the initial infection.
Where is the Nipah virus found?
Human outbreaks of the Nipah virus have been identified only in South and Southeast Asia, mainly in rural or semi-rural locations. Countries with previously reported outbreaks include:
• Bangladesh (where cases occur almost annually since 2001);
• India (including outbreaks in Kerala, in southern India, since 2018, and a current outbreak in West Bengal);
• Malaysia;
• Philippines;
• Singapore.
Although antibodies against the Nipah virus have been detected in bat species across Asia, Ghana, and Madagascar, human outbreaks have not occurred outside the South and Southeast Asia region. Find details of the latest news on Nipah virus outbreaks on the TravelHealthPro site.
Person-to-person transmission of the Nipah virus has also been reported among family members and caregivers of infected patients.
How is the Nipah virus transmitted?
Although human infections can arise from direct contact with an infected animal and its secretions, many infections result from the consumption of fruits or fruit products (such as raw or partially fermented date palm sap) contaminated with feces, urine, or saliva from infected fruit bats. Date palm sap is often known as Khejur Juice when raw and as Tari or Khajuri Tadi when fermented.
Person-to-person transmission is possible through close contact with an infected person or their bodily fluids. This has been documented in Bangladesh and India, most commonly among family members and close contacts who care for infected patients. Those with respiratory symptoms may pose a transmission risk.
How is Nipah virus treated?
Currently, there is no proven specific treatment for Nipah virus infection, and no preventive vaccine is licensed for use.
Treatment is limited to intensive supportive care for those with severe infections.
Several experimental therapies are in development or early clinical trials, including monoclonal antibodies, fusion inhibitors, and novel antivirals. UKHSA and The Pirbright Institute are supporting the development of henipavirus vaccines – a genus (or group) of viruses that includes the Nipah virus. The World Health Organization has listed the Nipah virus as an epidemic threat requiring urgent research and development action, including vaccine development.
How to prevent the spread of Nipah virus?
For those traveling to endemic areas, prevention focuses on avoiding exposure:
• avoid contact with bats and their environments, and sick animals;
• do not consume raw or partially fermented date palm sap – if consuming date palm sap, make sure it has been boiled first;
• wash all fruits thoroughly with clean water and peel before eating; avoid consuming fruits found on the ground or fruits that appear to have been partially eaten by animals;
• use protective clothing and gloves when handling sick animals and during slaughter procedures;
• practice good hand hygiene, particularly after caring for or visiting sick people;
• avoid close unprotected contact with anyone infected with Nipah virus, including contact with their blood or bodily fluids.
In healthcare settings, rigorous infection prevention and control measures are essential, including contact, droplet, and aerosol precautions for suspected and confirmed patients.
What should I do if I’m worried?
The risk to tourists visiting endemic countries is very low if standard precautions are followed. The risk may be higher for those who participate in local practices, such as collecting and consuming date palm sap.
If you develop symptoms while abroad in an endemic area, seek medical advice immediately. If you develop symptoms after returning to the United Kingdom, contact your healthcare provider and make sure to mention your recent travel history.
Source: https://ukhsa.blog.gov.uk/