West Nile Virus

August 18, 2023

3 min read

West Nile Virus is a mosquito-borne infection that can cause neurological disease and even death in humans. It is one of the primary mosquito-borne diseases in the continental U.S.

What is West Nile Virus (WNV)?

Typically common during the mosquito season ranging from summer to fall, the West Nile virus spreads to people through the bite of a mosquito that is infected with the virus. The virus can infect humans, horses, birds, and in rare cases, it can spread through organ transplants, blood transfusions, and from the placenta to the fetus.

Most people with WNV do not feel sick, with 1 in 5 having mild flu-like symptoms. However, the West Nile virus, if it enters the brain, can cause life-threatening diseases like:

Meningitis or inflammation of the brain and spinal cord lining
Encephalitis or inflammation of the brain
Meningoencephalitis or inflammation of the brain and its surrounding membrane

What causes the West Nile virus?

West Nile virus typically spreads through the bite of an infected female mosquito. The mosquitos get infected by biting an infected bird. Crows and Jays are the common birds that are linked to the virus.

The virus does not spread among humans, although being a blood-borne disease, it can spread through blood transfusion, organ donation, and from infected pregnant mothers to their unborn fetuses.

What are the symptoms of the West Nile virus?

In most cases, West Nile virus does not cause any symptoms. In others, it can cause mild flu-like symptoms involving:

Body aches
Headaches
Fever
Skin rashes
Swollen lymph glands
Vomiting or diarrhea

Severe infections can happen in older adults and those with a weakened immune system when the virus crosses the blood-brain barrier. The symptoms may include:

High fever
Muscle weakness
Neck stiffness
Stupor with extreme lethargy and impaired consciousness
Convulsions
Tremors
Paralysis
Disorientation
Coma

How is the West Nile virus diagnosed?

Your medical provider shall look into the symptoms and consider whether the person has traveled to locations where the virus has been found. The doctor shall send blood samples to the lab to diagnose the disease.

The virus can be diagnosed through tests like:

The ELISA test or Enzyme-linked immunosorbent Assay test
Neutralization Assays
Virus detection by RT-PCR Assay
Virus isolation through cell culture

People with symptoms of meningitis or encephalitis can get a lumbar puncture that collects fluid from the spine and brain for lab testing.

How is the West Nile virus infection treated?

Your medical provider will decide on the treatment based on your

Age
Medical history
Level of sickness
Ability to handle specific medications, therapies, and procedures
Opinions and preferences

Most West Nile infections go away on their own. Acetaminophen and Ibuprofen can be prescribed to treat minor aches and pains. You need to drink plenty of fluid to prevent dehydration.

In cases with more severe symptoms, where a person gets meningitis or encephalitis, the treatment may involve intense supportive therapies like:

Hospitalization
Nursing care
Ventilation or breathing support
Intravenous or IV support
Prevention of pneumonia or urinary tract infections

No vaccine is available for the prevention of the virus in humans.

How is the West Nile virus infection prevented?

West Nile virus infection can be prevented by:

Preventing transmission in animals and birds

As the virus outbreaks in birds and horses before infecting humans, an animal health surveillance system must be established to detect the viral infection in birds and horses. Dead birds incidence must be reported to the local authorities.

Reducing infection risks in people

Without a vaccine, the West Nile virus infection in people can be reduced by spreading public awareness about the disease. People must be educated about the risk factors and ways to prevent mosquito bites from spreading the virus.

You can prevent the West Nile virus by avoiding mosquito bites while visiting areas prone to the virus outbreak. Using mosquito nets, mosquito repellants, mosquito coils, and vaporizers and wearing protective clothing can prevent the virus infection.

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