The National Academies: What You Need To Know About Infectious Disease

The National Academies

What You Need To Know About Infectious Disease

Nipah Virus

Nipah virus is an emerging zoonotic virus (a virus transmitted to humans via animals). First recognized in 1999 during an outbreak among pig farmers in Malaysia, there have been 12 outbreaks since then, all in South Asia. In the initial outbreak, most people became infected because of direct contact with sick pigs. It is believed that transmission occurred via respiratory droplets, contact with throat or nasal secretions from the pigs, or contact with the tissue of a sick animal. Later outbreaks appear to have been the result of the consumption of fruits or fruit products (particularly date palms) contaminated with urine or saliva from infected fruit bats, which are believed to be the natural host for the virus, or possibly direct human-to-human transmission through contact with an infected person’s secretions and excretions. Although Nipah virus has caused only a few outbreaks, it infects a wide range of animals and causes severe disease and death in people. Infection with the Nipah virus can cause encephalitis (inflammation of the brain) or respiratory diseases.

People infected with Nipah virus can experience a range of responses, from no symptoms at all to fatal encephalitis. Following infection, symptoms may appear anywhere from 4 to 45 days later. Initial infection may cause influenza-like symptoms, including fever, headaches, muscle pain, vomiting, and sore throat. This may be followed by more acute symptoms, including dizziness, drowsiness, altered consciousness, and neurological symptoms indicating acute encephalitis. Some people may have atypical pneumonia and severe respiratory problems, such as acute respiratory distress. In severe cases, encephalitis and seizures occur, progressing to a coma within 24 to 48 hours.

There is no treatment or vaccine available for people or animals. The main approach to managing the infection is treatment of the symptoms.

Protective clothing should be worn when handling sick animals or their tissues (including during slaughtering or culling procedures) to prevent animal-to-human transmission. To reduce the risk of bat-to-human transmission, handling of date palm sap should be reduced. Freshly collected date palm juice should be boiled before drinking, and the fruit should be thoroughly washed and peeled before eating. To reduce the risk of human-to-human transmission, close physical contact with infected people should be avoided. Gloves and protective equipment should be worn when taking care of ill people. Regular hand washing after visiting or caring for sick people is advised.


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What do you know about infectious disease?

Which are larger?

  • Correct!

    Bacteria are 10 to 100 times larger than viruses.

  • Sorry, that’s incorrect.

    Bacteria are 10 to 100 times larger than viruses.

Infectious Disease Defined


The process of strengthening the body’s defense against a particular infectious agent.

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