What is the West Nile virus?

Fact Checked

The West Nile virus is spread by mosquitoes that are infected after biting birds that carry the virus. Once an infected mosquito bites an animal or human, the virus is injected via the saliva of the mosquito into the bite site.

Other modes of transmission aside from mosquito bites include:

  • Via the placenta from mother to infant
  • Breastfeeding
  • Transplant of infectious organs
  • Transfusion of infectious blood products


In some instances, the virus can cause West Nile fever which is a mild illness.

In most cases, the West Nile virus will not trigger illness or only a mild self-limiting febrile condition. In some instances, the virus can cause West Nile fever which is a mild illness. The indications of West Nile fever strikingly resemble the flu and might include:

  • Headache
  • Fever
  • Swollen glands
  • Skin rash
  • Body aches

In uncommon cases, the West Nile virus can trigger a serious illness such as West Nile meningoencephalitis which involves inflammation of the brain or meningitis which is characterized by swelling of the protective membrane that surrounds the brain and spinal cord. The indications of serious illness might include:

  • High fever
  • Headache
  • Stiff neck
  • Muscular weakness
  • Diminished alertness and mental abilities
  • Involuntary muscle movement
  • Paralysis
  • Coma

Do I have the West Nile virus?

Most of the symptoms of West Nile virus are generally mild and settle as the body fights the infection. The doctor should be consulted if the symptoms do not settle or if they are a cause of concern.

In some cases, the doctor might require a blood test to detect for the presence of the virus in the bloodstream.


Even today, there is no specific treatment for the West Nile virus. It is important to note that the treatment is focused on alleviating any of the undesirable symptoms such as headache and body aches.

Individuals with severe illness might be hospitalized so that supportive measures are started such as intravenous fluids and breathing support as their bodies fight the virus.

At the present, there is still no available vaccine approved for use among humans but studies are on way in developing a vaccine.

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