Common Summer Illnesses

Summertime infections are more common than you might think and there are many infections that are common in the late spring and summer. This is surprising to most parents who expect infections, such as the cold and flu, to occur in the winter.

Teenage girl blowing nose on train
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Mosquito-Borne and Tick-Borne Illnesses

Mosquito-borne infections are commonly caused by the arboviruses and can lead to West Nile encephalitis, St. Louis encephalitis, and dengue fever. They are more common in the summer, specifically late summer and early autumn. Some newer arboviruses that have hit the news the past few years are Eastern equine encephalitis and especially Zika.

Tick-borne illnesses include Lyme disease, Rocky Mountain Spotted Fever, and ehrlichiosis. These are also more common during the summer months.

Mosquito and tick-borne infections can be avoided by preventing your child from getting bitten by ticks or mosquitoes. In high-risk areas for Lyme disease, you should have your child wear long-sleeved shirts and long pants with high socks and boots. You can also tuck your child's pant legs into his socks and use a tick repellent. Also, check your child's body for ticks at least once or twice a day, especially if you have been camping or playing in tick-infested areas (grassy, brushy, or wooded areas).

Be sure to tell your pediatrician if your child has experienced a tick bite.

An insect repellent with DEET, citronella, or soybean oil can help to prevent mosquito bites. Wear light-colored clothing and avoid using any scented soaps or other products since the fragrances can attract insects. Avoid areas with insect nests. Citronella and soybean oil can help to prevent mosquito bites.

Food Poisoning

Another important cause of infections and illness in the summer months is food poisoning or food-borne illnesses. Because bacteria thrive in warm, moist environments, food poisoning is relatively frequent in the summer when there is an increased number of cookouts and picnics.

Food poisoning can be prevented by frequently washing your hands and cooking surfaces, not allowing foods and utensils to become cross-contaminated, cooking foods to their proper temperature, and promptly refrigerating leftovers.

Amebic Meningoencephalitis

Naegleria fowleri can cause amebic meningoencephalitis, a rapid and usually fatal infection. It affects children who swim in warm, polluted, and stagnant water, such as a lake or poorly chlorinated swimming pool.

Summer Viruses

Polio, an enterovirus, is the most notorious illness caused by a summertime virus. In the 1940s and 1950s, parents often refused to let their children go outside and play because of the fear of the poliovirus. Children who were infected would have a mild sore throat and fever, and then within a few days, could develop meningitis and/or paralysis. Thankfully, because of routine immunizations, polio is close to being eradicated in most parts of the world.

There are other enteroviruses which can cause illnesses, such as group A and B coxsackieviruses, echoviruses, and enteroviruses. These viruses usually cause mild respiratory symptoms (cough and runny nose) and gastrointestinal symptoms (diarrhea and vomiting), but they can also cause more severe infections, such as aseptic meningitis, encephalitis, and myocarditis.

Other common childhood illnesses that are caused by nonpolio enteroviruses include hand, foot, and mouth disease (HFM), caused by the Coxsackie A16 and Enterovirus 71 viruses. Children with HFM can have blisters or ulcers in the mouth and on their hands and feet. Or, they can have ulcers just in their mouth, which is called herpangina.

Another common summertime virus is parainfluenza virus 3. This virus can cause croup, bronchiolitis, pneumonia, or just a cold. The characteristic barking cough of croup, which is often described as sounding like a seal, makes this virus easy to identify in the summertime. Overall, though, croup is more common in the winter.

Adenoviral infections are also more common in the winter, but they can also occur in the early summer. Symptoms can include fever, sore throat, and other upper respiratory tract infections. Adenovirus can also cause pharyngoconjunctival fever, with a sore throat, fever and red eyes without discharge or matting.

Travel Concerns

It is also important to keep in mind that different parts of the world have different seasonal patterns for when infections occur. So if you are from the U.S. and you visit the Southern Hemisphere on a "summer vacation," then you may be exposed to people that are at the peak of their flu season. Or if there are a lot of tourists, they can bring the infection to you.

Preventing Summertime Infections

Many infections are spread from fecal-oral and respiratory routes from other infected children. Simple hand washing and avoiding sharing food or drinks with other children, especially sick children, can help greatly reduce your child's chances of getting sick too. Being extra careful at summer camp, where children are exposed to a lot of other people, can also help to reduce infections.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Biesiada G, Czepiel J, Leśniak MR, Garlicki A, Mach T. Lyme disease: review. Arch Med Sci. 2012;8(6):978-82. doi:10.5114/aoms.2012.30948

  3. Centers for Disease Control and Prevention. Foodborne Germs and Illnesses.

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By Vincent Iannelli, MD
 Vincent Iannelli, MD, is a board-certified pediatrician and fellow of the American Academy of Pediatrics. Dr. Iannelli has cared for children for more than 20 years.