Mosquito bite prevention helps protect children from West Nile virus

In warm climates like Southern California, multiple species of mosquitoes can bite year-round. While telltale red, itchy bumps are the most common side effect of mosquito bites, these pests can also pass diseases, like West Nile virus, on to humans.

Most people infected with West Nile virus experience only mild illness or no symptoms at all, but sometimes infections can lead to serious illness.

You can minimize your family’s risk for mosquito bites and disease-and help your neighbors and community members stay healthy as well-by taking precautions to deter bites and keeping outdoor areas clear of standing water.

Michael Smit, MD, MSPH, hospital epidemiologist and Medical Director of Infection Prevention and Control at Children’s Hospital Los Angeles, offers helpful advice and information to families looking to protect themselves from mosquito bites and disease.

To protect yourself from mosquito bites and West Nile virus infections, please follow advice that can be found on the Los Angeles County Department of Public Health and California Department of Public Health websites. This includes using EPA-registered insect repellents, wearing long sleeves and pants, and draining standing water around your home.”

Michael Smit, MD, MSPH, hospital epidemiologist and Medical Director of Infection Prevention and Control. Children’s Hospital Los Angeles

It’s also important to understand the details of West Nile virus itself.

How serious is West Nile virus in California?

West Nile virus infections in California spiked in 2026, reaching a five-year high.

The highest concentrations of infections have been reported in Southern California, including East Los Angeles, the San Fernando Valley, and areas of the South Bay like Long Beach and Cerritos.

One of the reasons mosquito activity has been higher in recent years is due to unseasonably warm, rainy, and humid weather patterns like El Niño. Warmer winters in California means mosquitoes can thrive any time of year.

West Nile virus in children

Most kids infected with West Nile virus never experience any symptoms.

Around 20% of kids may develop West Nile fever.

Symptoms include:

• Fever
• Headache
• Body aches and joint pain
• Nausea and/or vomiting
• Rash

In less than 1% of infections, the virus affects the central nervous system and causes West Nile encephalitis, West Nile meningitis, or West Nile virus acute flaccid myelitis. This level of infection is a medical emergency and requires a visit to your local emergency department.

Symptoms include:

• High fever
• Neck stiffness
• Disorientation
• Muscle weakness
• Tremors

If your child has mild symptoms and you are unsure if you should seek medical care, you can use CHLA’s Symptom Checker or contact your pediatrician.

How to help kids avoid mosquito bites

Apply insect repellent to exposed skin.

Look for insect repellent products registered with the Environmental Protection Agency (EPA). These products are confirmed to be safe and effective, even for women who are pregnant and breastfeeding.

Common EPA-approved repellents for children 2 months and older contain active ingredients such as:

• DEET (20% to 30%)
• picaridin (10% to 20%)
• 2-undecanone (7.5%)

Less common EPA-approved repellents for children 3 and older may contain:

• Oil of lemon eucalyptus, also called p-Menthane-3,8-diol or PMD
• IR3535, also called 3-[N-Butyl-N-acetyl]-aminopropionic acid or ethyl ester

The concentration of each repellent, listed as a percentage on the label, helps indicate how long the product will be effective. Doctors recommend lower concentration formulas for children, like products with 10% DEET, which provides protection for up to two hours.

Thoroughly read each product’s label and follow application and safety instructions.

Create a physical barrier with clothing or netting.

• Use insect netting on strollers, carseats, or playpens when outdoors.
• Dress babies and children in loose fitting long sleeves and pants. Layer clothing when possible.
• Install screens on open windows and check for holes.

Treat clothing with permethrin.

Use a 0.5% permethrin clothing spray on outer layers, pants and shirts according to the product’s usage directions. These home treatments can last for multiple washes.

Reduce exposure to potential habitats for mosquito growth.

Mosquitoes love moisture and humidity. Some precautions:

• Remove or regularly dump standing water around the outside of your home or community, including buckets, open trash cans, kiddie pools, or flowerpots.
• When possible, avoid spending prolonged time outside around dawn and dusk.