West Nile Virus

What is West Nile Virus?

From: MedlinePlus, National Library of Medicine

West Nile virus (WNV) is an infectious disease. It is most often spread by the bite of an infected mosquito. Most people have no symptoms, while some may develop mild symptoms. But WNV can sometimes cause serious symptoms if the virus enters your brain.

How does West Nile Virus spread?

From: MedlinePlus, National Library of Medicine

WNV usually spreads to people through the bite of an infected mosquito. However, in rare cases, it can spread from person-to-person. This can happen through an organ transplant or blood transfusion. If you are preganant you can spread WNV to your fetus during pregnancy or delivery. And after delivery, it can spread to the baby during breastfeeding.

Who is more likely to develop West Nile Virus?

From: MedlinePlus, National Library of Medicine

Anyone could be bitten by an infected mosquito and get WNV. But certain people are at higher risk for more serious illness they get a WNV infection. They include people who:

• Are over age 60
• Have certain medical conditions, such as cancer, diabetes, high blood pressure, or kidney disease
• Had an organ transplant

What are the symptoms of West Nile Virus?

From: MedlinePlus, National Library of Medicine

Symptoms can be mild to severe. But most people have no symptoms or mild symptoms.

Mild symptoms of WNV can include:

These symptoms usually go away on their own within a few days to several weeks. But some people will have weakness or fatigue that lasts for weeks or months.

Although rare, If West Nile virus enters your brain, it can be life-threatening. It may cause inflammation of the brain (encephalitis) or inflammation of the tissue that surrounds the brain and spinal cord (meningitis).

Serious symptoms of WNV can include:

• Fever
• Headache
• Body aches
• Vomiting
• Diarrhea
• Skin rash
• High fever
• Headache
• Neck stiffness
• Numbness
• Coma
• Muscle weakness
• Vision loss

How is West Nile Virus diagnosed?

From: MedlinePlus, National Library of Medicine

To find out if you have WNV, your health care provider:

• Will do a physical exam
• Will take your medical history, including asking about your symptoms
• May order blood tests

What are the treatments for West Nile Virus?

From: MedlinePlus, National Library of Medicine

There are no specific vaccines or treatments for human WNV disease. But rest, fluids, and over-the-counter pain medicines may relieve some symptoms. You may need to be hospitalized if you have serious symptoms.

Can West Nile Virus be prevented?

From: MedlinePlus, National Library of Medicine

There are no vaccines or medicines to prevent WNV. The best way to avoid WNV is to help prevent mosquito bites:

• Wear insect repellent with DEET or another U.S. Environmental Protection Agency (EPA)-registered insect repellent. Make sure to follow the instructions for using the repellent.
• Wear long-sleeved shirts and pants if you're outside.
• Get rid of mosquito breeding sites by emptying standing water from flowerpots, buckets, or barrels.
• Stay indoors between dusk and dawn, when mosquitoes are most active.
• Use screens on windows to keep mosquitoes out.

Centers for Disease Control and Prevention (CDC)

Understanding terms used in the source

These definitions explain medical words used above. A definition is not evidence that another condition is present, and it does not predict how a symptom will develop. Ask the clinician which terms apply to the actual examination or test result.

Diarrhea

Abnormally increased frequency (usually defined as three or more) loose or watery bowel movements a day.

Headache

Cephalgia, or pain sensed in various parts of the head, not confined to the area of distribution of any nerve.

Vomiting

Forceful ejection of the contents of the stomach through the mouth by means of a series of involuntary spasmic contractions.

Fatigue

A subjective feeling of tiredness characterized by a lack of energy and motivation.

Which doctor should you see?

The suggested department for discussing West Nile Virus is Infectious Diseases, with a general physician / infectious disease specialist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which exposure or organism is suspected, and what evidence would confirm it?
• Are precautions, vaccination or advice for close contacts relevant to this infection?
• What should happen if symptoms worsen or do not improve as expected?

Treatment discussions and follow-up

Where the source describes treatments, these are an overview of possible care, not a prescription for an individual. Ask which option applies to the confirmed diagnosis, what benefit is expected, what adverse effects to watch for and how progress will be assessed. Availability, approvals and local practice can differ from the country described in the source.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.