Home Health A-Z West Nile Virus (WNV): Symptoms, Treatment, Risk Factors & Prevention

West Nile Virus (WNV): Symptoms, Treatment, Risk Factors & Prevention

Verified By Apollo Doctors July 25, 2022 956 0
West Nile Virus(WNV): Symptoms, Risk Factors, Prevention and Treatment
West Nile Virus(WNV): Symptoms, Risk Factors, Prevention and Treatment

Birds are the instinctive host of the West Nile virus or sometimes known as WNV. Mosquitos develop the virus by biting the infected birds. Most human cases of WNV are by mosquito bites. Other than humans, this virus can affect horses and many other species of birds.

West Nile Virus in Humans

In 1951 the first human being was affected by this virus in Israel. The disease is known to be very mild and very rarely causes any severe illness in those affected . 

West Nile virus is found in 38 countries at present. Some of the countries with the virus are France, Italy, Russia, and Spain.

People of old age and people with a chronic disease like diabetes or cancer have a higher risk from the disease. However, the chances of severe illness are less.


Eighty per cent of people infected do not feel any symptoms. Statistics show this is not a serious disease.

Out of the rest of the 20%, few of the infected people feel mild symptoms. These symptoms are almost the same as viral fever. Mild symptoms of West Nile virus include :

·         Fever

·         Nausea

·         Headache

·         Skin rash

·         Fatigue

·         Body ache

Rarely does someone show any severe symptoms. These kinds of symptoms occur when the virus causes a neurological infection. The symptoms include,

·         Severe headache

·         Sore throat

·         Tremors

·         Seizures

·         Vision loss

·         Numbness

·         High fever

·         Coma

In very rare cases, muscle weakness can remain permanent.

Risk Factors

Just like any other virus, the West Nile virus also affects your immune system. So those who have a weak immune system due to any reason contain more risk of getting severe symptoms of WNV.

Travelers visiting endemic areas are at risk of catching the virus, especially people over 60 with a weakened immune system. People with other diseases like cancer, high blood pressure, or diabetes are also at higher risk.

When to see a doctor

Mostly there is no need for a consultation. Mild symptoms will most likely go away by themselves. If you feel any of the severe symptoms mentioned above, then make an appointment with your physician right away.

If the doctor suspects anything serious, he/she will order some tests which will figure out the actual cause of the symptoms you are facing.

To diagnose WNV, a simple blood test may show a rise in the antibodies to the virus. It takes up to 3 to 8 days for the antibodies to show. If the doctor suspects any neurological damage due to the disease, he/she may order an MRI or EEG to measure the brain’s activity and find out if there is any inflammation.


An infected person or an animal cannot spread the virus except by bite. The maximum chance of catching the West Nile virus is by a mosquito bite.

There are no preventive medications for the virus. Some of the other preventive measures one can take are,

  • WNV is commonly found in Africa, North America, Europe, West Asia, and the Middle East, so people living there or travelling there should be extra careful
  • Use mosquito repellent sprays or gel while going out
  • Wear full-length clothes to cover your skin
  • Don’t leave water unused or contaminated
  • Wear neutral colors and apply sunscreen before stepping out
  • Get your windows netted to stop mosquitoes from entering your house

Mosquitos have trouble surviving in winters, so these precautions should be taken more seriously during the summer.


Most cases of the West Nile virus do not require any treatment. Severe cases may require hospitalization.

There is no cure or vaccine specifically for humans as of now. If you consult a doctor, he/she might provide medications to manage symptoms such as pain killers for body aches and pills to reduce fever. If you are experiencing brain swelling, intravenous fluids may be given to you by your doctor.

A therapy for the West Nile virus called interferon therapy is also used for those who develop encephalitis due to WNV.


There is no vaccine for the West Nile virus .

The odds of the diseases getting serious are very less, and you might recover very quickly. If the mild symptoms are making you uncomfortable, then medications for managing these symptoms can be very helpful.

If you are feeling any of the severe symptoms mentioned above, see a doctor now.

Frequently Asked Questions (FAQs)

1.Can you die from the West Nile virus?

Less than 1% of the people affected by the virus face severe symptoms. An even fewer number of people struggle in their recovery. Chances of death through WNV are very slim, but it is possible. More than 90% of the deaths related to the virus are recorded due to necrotic damage. Also, age factor play a role as more severe cases are seen in people over 60.

2. Is WNV contagious?

No, the West Nile virus cannot be transmitted from human to human. The disease originates from birds and is transferred to humans through mosquitos.

3. Can pet dogs and cats catch the virus?

Dogs and cats can be affected by the virus. However, they cannot transmit it to people. There are very few chances of animals not recovering from the virus. Most of them, if in a healthy condition, recover very quickly.

Verified By Apollo Doctors
At Apollo, we believe that easily accessible, reliable health information can make managing health conditions an empowering experience. AskApollo Online Health Library team consists of medical experts who create curated peer-reviewed medical content that is regularly updated and is easy-to-understand.

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