Southwest Utah Public Health Department Logo
Southwest Utah Public Health Department

west nile virus

West Nile Virus (WNV) is a virus that is spread from infected mosquitoes to other animals including humans, birds, horses, and some other animals. The most common way to become infected is through a mosquito bite.


The best way to prevent West Nile virus and other mosquito-borne illnesses is to avoid exposure to mosquitoes and eliminate potential mosquito breeding grounds which are typically standing water.

Prevent Mosquito Breeding Grounds

  • Unclog roof gutters.
  • Empty swimming pools and check for standing water on pool covers.
  • Change water in pet bowls and bird baths regularly.
  • Removed tires and any containers that could hold water.

Reduce Exposure to Mosquitoes

  • Avoid unnecessary outdoor activities when mosquitoes are present and active including dawn, dusk, and early evening.
  • Wear clothing that covers as much skin as possible.
  • Apply EPA approved mosquito repellent.
  • If you notice mosquitoes, leave the area as quickly as possible.

West Nile Virus is not contagious and cannot be transmitted person to person. West Nile can only be transmitted by infected mosquitoes.


Most people infected with WNV do not develop signs or symptoms, or develop mild symptoms such as:

  • Fever
  • Mild headaches
  • Body aches
  • Joint pains
  • Nausea
  • Vomiting
  • Rash

Mild symptoms tend to go away on their own, but more severe signs and symptoms can include:

  • Severe headaches
  • High Fever
  • Disorientation
  • Sudden weakness
  • Vision loss
  • Paralysis
  • Neck Stiffness

Consult your doctor or another medical professional if you are concerned about possible West Nile infections.


Healthcare providers diagnose infection based on:

  • Signs and Symptoms
  • History of exposure to mosquitoes.
  • And, lab tests results such as, blood samples or cerebrospinal fluid (CSF) samples for presence of antibodies or antigens.

There are no vaccines or specific medicines available for West Nile infections. Rest, fluids, and over the counter pain medications may relieve some symptoms. More severe cases may need supportive treatments provided by medical professionals.

    All treatment methods should be recommended by a Healthcare Provider to ensure appropriate level of care for each case.

    Translate >