Midwesterners deserve their summer fun after typically long, dreary winters and rainy springs. But when summer arrives, we are warned about sunburn, dehydration, picnic food spoilage, Lake Michigan undertows, red-winged blackbird attacks, bugs, and more. Recent warnings may put some folks on edge: West Nile virus has been found in Evanston mosquitos, and the Centers for Disease Control (CDC) advised that tick-borne diseases, including the bacterial infection Lyme disease, are on the rise. A bit of knowledge and some preventive measures should help everyone avoid these bloodsucking pests so they do not have to stay inside until October.
Millions of Americans each year seek treatment for tick bites, most of which are harmless (but can cause a serious case of the creeps). The number of reported tick-borne disease cases is increasing and the geographic range of disease-carrying ticks is expanding, according to the CDC. The average number of reported Lyme disease cases in the U.S. tripled in the past 15 years, with around 30,000 cases now reported annually, although researchers estimate the actual number is closer to 300,000. Mild winters may be prolonging tick season, increasing opportunities for bites and disease transmission.
In 2015, 95% of confirmed Lyme disease cases were reported from these 14 northeast, mid-Atlantic and upper Midwest states: Connecticut, Delaware, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia, and Wisconsin. The offenders are Blacklegged ticks (Ixodes scapularis) – flat, rusty-brown, eight-legged creatures ranging from poppy seed-sized (larvae) to 5 millimeters long (adults). After a blood feeding, engorged ticks expand up to 10 millimeters long.
Ticks do not fly or jump; rather they hitch a ride when potential hosts such as deer, mice, and other rodents, dogs, cats, or people brush past them. They can attach anywhere but often migrate to warm, dark areas such as the groin, armpits, neck and scalp before settling in to feed. After sucking their fill, they fall off and begin their next life phase. Also called deer ticks, Blacklegged ticks transition from the larval stage to nymph to adult within about two years; males die soon after mating and females after laying up to 3,000 eggs. Many ticks simply die of starvation if they cannot find a host.
A tick must stay attached to its host for 36 to 48 hours before Lyme disease (Borrelia burgdorferi) can be transmitted. Nymphs often succeed in transmitting the bacterium because they are tiny and hard to see, whereas adult ticks are more easily discovered and removed before causing any harm. The risk of acquiring Lyme disease from a tick bite is less than 1.5%, even in areas where the disease is common, says Linden Hu, M.D., Professor of Medicine at Tufts University School of Medicine.
An uninfected tick bite usually leaves a small red bump that should disappear after a few days. The Mayo Clinic advises seeking medical attention as soon as possible if the following symptoms appear within 30 days, and especially if the tick stayed attached for 36 to 48 hours and is from a high-risk Lyme disease region:
• an expanding red bull’s-eye rash, called erythema migrans, can spread several inches in diameter. Not always painful or itchy, the rash can appear elsewhere besides the tick’s feeding site;
• flu-like symptoms including fever, chills, fatigue, headache, neck stiffness, body aches;
• joint pain and swelling, especially in the knees and other large joints;
• neurological problems such as inflammation of the brain and spinal cord lining (meningitis), temporary facial droop called Bell’s palsy, nerve pain, dizziness, shortness of breath, numbness, weakness or tingling in limbs, heart palpitations, short-term memory problems.
Treatment with antibiotics is most effective when started early; if delayed, Lyme disease can linger and become chronic.
The CDC advises extra vigilance in warmer months (April to September) when ticks are most active. Also:
• avoid wooded and brushy areas with high grass and leaf litter.
• walk in the center of trails.
• use repellent with 20% or more of DEET, picaridin, or IR3535 on exposed skin.
• treat clothing, socks, boots, shoes, and tents with products containing 0.5% permethrin (also a repellent) or buy pre-treated gear.
• bathe or shower within two hours of being outside to wash off any ticks.
• check body thoroughly for ticks, and check children as well, paying close attention to hairy areas, armpits, groin, bellybutton, behind the neck and knees.
• check gear, pets, clothing, and accessories.
• put clothes in a very hot dryer for 10 minutes to kill ticks. If necessary, wash clothes in hot water first.
If a tick is found:
• grasp it with fine-tipped sterilized tweezers as close to the skin’s surface as possible.
• pull upward with steady, even pressure without twisting or jerking, which
can cause the mouth parts to break off
and remain in the skin. If this happens, remove the mouth-parts with tweezers.
If the mouth does not come out easily, leave it alone and let the skin heal.
• after removal, clean the bite area and hands with rubbing alcohol, an iodine scrub, or soap and water.
• to dispose of ticks, submerse in alcohol, place in a sealed bag/container, wrap tightly in tape, or flush down the toilet. Never crush ticks.
While ticks are creepy, mosquitos can be wildly annoying: hovering almost invisibly before they strike and leaving madly itching welts in their wake. They have numbers on their side, too: kill one (not always easy) and there seem to be dozens more waiting to sink their sippers into some skin. Mosquitos transmit diseases such Zika, dengue, chikungunya, and malaria, although mercifully not in this area. Unfortunately some local mosquitos carry West Nile virus (WNV), which the North Shore Mosquito Abatement District (NSMAD) recently found in mosquito traps around Evanston, Glenview, Morton Grove, Niles, and Skokie.
Illinois experienced the country’s worst West Nile virus outbreak in 2002, with 884 human cases and 66 deaths that year. Outbreaks and fatalities have fluctuated since then, depending on the weather. Cooler weather reduces mosquito populations and WNV while hot, dry conditions – typically in July and August – optimize mosquito breeding and increase the risk of WNV transmission. So far this year there are no confirmed WNV cases in the State, according to the Illinois Department of Public Health.
Hawks and owls can pick up the virus by eating dead infected birds, although most birds survive exposure. Mosquitos feed on those infected birds and spread the virus to humans and other animals. Crows and blue jays are especially vulnerable and often die from WNV, so the Cook County Public Health department (CCPH) encourages people to report dead bird sightings at: tinyurl.com/report-dead-birds.
About 20% of people infected by WNV will develop symptoms including fever, nausea, headache, and muscle aches, which often resolve on their own in a few days to a few weeks, according to the CDC. The other 80% might never show any signs of illness. Symptoms surface anywhere from 3 to15 days after being bitten by an infected mosquito. WNV risk increases in people over 50, and in people with compromised immune systems. Medications can relieve symptoms, but there is no vaccine or antibiotic treatment for WNV.
More severe symptoms can include high fever, stiff neck, confusion, muscle weakness, tremors or seizures, and partial paralysis. Fewer than 1% of infections cause inflammation of the brain (encephalitis) or inflammation of the brain and spinal cord linings (meningitis). Seek medical treatment as soon as possible if such symptoms appear.
The North Shore Mosquito Abatement District – which conducts stealthy (but pre-announced) nighttime spraying rounds called Adult Mosquito Control Operations – recommends minimizing mosquito bites with insect repellent, wearing loose fitting clothing, and avoiding peak mosquito feeding times at dawn and dusk. Cook County’s “Fight the Bite” program urges residents to practice the Three Rs:
• Repel mosquitos using products containing DEET;
• Repair or replace torn window and door screens;
• Remove standing water in birdbaths, flower pots, old tires, watering cans, etc.
to discourage mosquito breeding.
Dracula might shrink away from garlic, but the stinking rose does little to repel mosquitos and ticks. Even double-blind studies on humans have failed to find garlic any more effective in preventing mosquito and tick bites than a placebo. It may be best to try the suggested precautions for a vampire-free summer.