Skip Ribbon Commands
Skip to main content
Health Issues
Text Size

Diseases Spread by Insects

Diseases spread by insects are a major cause of illness to children and adults worldwide. The following is information about West Nile virus, Lyme disease, and Rocky Mountain spotted fever.

West Nile Virus

In the United States, West Nile virus and outbreaks of various types of encephalitis get plenty of media coverage. These illnesses are carried by mosquitoes and transmitted to humans when the insects bite.


  • ​Most cases of West Nile virus are mild, with people showing no symptoms or having a fever, headache, and body aches.
  • Less commonly and occurring mostly in older adults, the nervous system is affected and symptoms may include a severe headache, high fever, stiff neck, confusion, seizures, sensitivity to light, muscle weakness, and loss of consciousness.

Lyme Disease

In some areas of the United States, Lyme disease is an important health concern. Deer ticks are one of the insects that spread the disease. Deer ticks are tiny, black-brown, biting insects about the size of a poppy seed.


  • The first and most obvious symptom of Lyme disease is a rash. It is a red spot surrounded by a light red ring that looks like a target and typically enlarges day by day.
  • In addition to the ring-like rash, some children have additional symptoms such as fever, fatigue, headache, aches and pain in muscles or joints, and swollen glands.
  • Occasionally, children develop a droop of an eyelid and/or the corner of the mouth (facial nerve palsy) or severe headache, vomiting, and stiff neck (meningitis). Weeks to months later (without antibiotic treatment), some children develop swelling of the knee or other joints (arthritis).

Rocky Mountain Spotted Fever

Despite the name, Rocky Mountain spotted fever currently occurs mostly in other regions of the United States, including North and South Carolina, Oklahoma, and Tennessee. Ticks spread this bacterial infection.


  • Fever
  • Severe headache
  • Confusion
  • Nausea
  • Vomiting
  • Rash—Most also get a rash that starts as flat red spots that become purple over time. It begins on the ankles and wrists and spreads to the palms and soles and then to the arms and legs and the trunk.

If your child has been bitten by an insect and shows any of the above symptoms of West Nile virus infection, Lyme disease, or Rocky Mountain spotted fever, call your child’s doctor.


Children need and love to be outdoors. The chance of your children becoming infected with West Nile virus, Lyme disease, or Rocky Mountain spotted fever is quite low. The best way to protect yourself and your children is to follow the guidelines in this article and also see our additional information on insect repellents. If you have any concerns about insect bites, talk with your child’s doctor.​

Last Updated
A Parent's Guide to Insect Repellents (Copyright © 2009 American Academy of Pediatrics, Updated 6/2012)
The information contained on this Web site should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.
Follow Us