West Nile Virus in Children: Symptoms and When to Seek Care

A family guide for mosquito season

MEDICALLY REVIEWED - APPROVED FOR WEBSITE PUBLICATION

This page is for general education only and does not replace individualized medical advice. This resource does not establish a doctor-patient relationship. For questions about your own child, contact your child's current healthcare professional.

Magnolia Pediatrics, Valley Children's Healthcare
2497 E. Herndon Avenue, Suite 101, Clovis, CA 93611  |  559-538-3070

West Nile virus is usually spread by the bite of an infected mosquito. Most infected people have no symptoms; some develop a flu-like illness, and severe illness is uncommon but can affect the brain and spinal cord. A mosquito bite alone does not mean a child has West Nile virus.

Urgent warning signs - check this first

Call 911 now for a seizure, severe trouble breathing, blue or gray lips or face, a child who is limp or unresponsive, or another life-threatening emergency.

Seek emergency medical care now for fever with a severe headache, stiff neck, confusion, unusual sleepiness or difficulty waking, muscle weakness, tremors, new trouble walking, vision changes, or repeated vomiting.

When to contact your child's healthcare professional

  • Fever, headache, body aches, unusual tiredness, vomiting, diarrhea, or rash during mosquito season, especially after many mosquito bites or travel to an area with West Nile activity.

  • Symptoms are worsening, the child cannot drink, is urinating much less than usual, has significant weakness, or the family is concerned about dehydration.

  • A child with a weakened immune system or significant chronic medical condition develops a fever or concerning symptoms after mosquito exposure.

What families may notice

  • Most people with West Nile virus have no symptoms. Mild illness can include fever, headache, body or joint aches, vomiting, diarrhea, or rash.

  • Symptoms generally begin days after an infected mosquito bite, but timing and symptoms overlap with many common childhood illnesses. Testing is decided by a clinician based on illness, exposure, and local activity.

  • Antibiotics do not treat West Nile virus. There is no licensed vaccine or specific antiviral treatment for people; care is supportive.

Comfort care and prevention

  • Offer fluids, rest, and comfort measures. Use fever or pain medicine only as directed by the product label or the child's clinician; do not give aspirin to children or teenagers unless specifically instructed.

  • Prevent mosquito bites with EPA-registered repellent used according to its label, loose long sleeves and pants when practical, and intact window and door screens.

  • Reduce mosquitoes around the home by emptying standing water from containers and following local mosquito-control guidance.

Related topics on this website

  • Fever and Illness: When to Seek Care

  • Headache in Children: When to Seek Care

  • Rashes and Skin Changes: When to Seek Care

  • Insect Bites and Stings in Children

Sources and medical review

Sources checked: August 15, 2026  |  Medical review completed: August 15, 2026

  • CDC: About West Nile Virus - https://www.cdc.gov/west-nile-virus/about/index.html

  • CDC: Symptoms of West Nile - https://www.cdc.gov/west-nile-virus/signs-symptoms/index.html

  • CDC: Preventing West Nile - https://www.cdc.gov/west-nile-virus/prevention/index.html