When most people think of diseases that are spread by tick bites, they think of Lyme disease. But Lyme disease is not the only disease that can be transmitted by the bite of a tick. Many of them cause severe illness and some can cause complications during pregnancy or birth or are linked to birth defects.
The Centers for Disease Control and Prevention reports that there are about 50,000 cases of tick-borne diseases each year in the United States. The incidence of tick-borne diseases is going up, with the number of reported cases doubling between 2004 and 2016.
There are several types of ticks and different ticks transmit different diseases. For example, the bacteria that causes Lyme disease is carried by the black-legged tick, also known as the deer tick. But this species of tick can also carry other diseases, including anaplasmosis, ehrlichiosis, and babesiosis. A different type of tick, the lone star tick, can carry Rocky Mountain spotted fever and ehrlichiosis. Some diseases can be spread by different species of ticks.
The diseases that are spread by tick bites vary by geography, with different diseases being prevalent in different parts of the country. Lyme disease occurs most frequently in New England, the northeastern states, and in the upper Midwest, but it is now being diagnosed in California, Oregon, and Washington as well. Rocky Mountain Spotted fever, despite the name, has been diagnosed throughout the United States, with the most cases being reported in North Carolina, Oklahoma, Tennessee, Arkansas, and Missouri.
Not every individual tick carries a disease and not every tick bite will transmit a disease. A tick may crawl on your body and not bite you. Even if a tick has bitten you, it has to stay attached to you for several hours, even more than a day, in order to transmit whatever disease it is carrying.
The worst time of year for tick bites is in spring and early summer. But bites become more common again in October and early November. They can happen all year round in many parts of the country.
As with most things, an ounce of prevention is worth a pound of cure when it comes to tick bites and tick-borne diseases.
Ticks like grassy and wooded areas, so hiking, hunting, and camping mean that you are in their territory. If you can, avoid the woods and areas with tall grass. If you are walking or hiking in the woods, stay to the center of the trail to minimize your exposure to ticks.
To prevent ticks from getting onto you when you are outside, treat your clothing and shoes with an insect repellent.
After you come back inside, check your clothing for ticks. Then check yourself for ticks. Pay attention to areas like under your arms, the back of your knees, around your waist (including your belly button), and between your legs. Use a mirror so that you can check at all parts of your body. Taking a shower after you come in from a hike or from gardening can reduce your risk of becoming infected because it helps wash off unattached ticks and allows you to check yourself easily.
If you find a tick attached to you, use clean tweezers to grab hold of the tick as close to the surface of your skin as possible. Pull the tick upward slowly. Don’t twist the tick and try not to crush it. Clean the site of the tick bite thoroughly with soap and water or a bit of hand sanitizer. Then wash your hands thoroughly.
Some diseases that are transmitted by a tick bite can be passed on to a baby through the placenta. Others are not known to do so but can make a pregnant woman very sick. Here is a short overview of some diseases commonly carried by ticks:
Lyme disease is a bacterial disease that can cause lasting problems if left untreated. It is carried by black-legged ticks If it is contracted during pregnancy, it has been linked to an increased risk of stillbirth and defects in the heart and urinary tract in the baby. The infection can be passed to the baby during the pregnancy. Symptoms include a red rash that spreads out from a paler center, but not everyone gets this rash. Other symptoms are similar to the flu. If left untreated, Lyme disease can cause arthritis, heart problems, and nerve and central nervous system problems, among other conditions.
Ehrlichiosis is actually two closely related diseases—anaplasmosis and human monocytic ehrlichiosis—that can look similar and are transmitted by a bite from a black-legged tick or a lone star tick. Both diseases can cause fever, chills, severe headache, muscle pain, and gastrointestinal problems.
Babesiosis is a disease caused by a parasite transmitted by a tick bite. The parasite infects red blood cells and symptoms include fever, chills, muscle and joint pain, headache, fatigue, nausea, and blood-shot eyes.
Rocky Mountain Spotted Fever can be spread by several types of ticks, including dog ticks and wood ticks. It is an extremely serious infection that should be treated as quickly as possible. Symptoms include fever, severe headache, muscle pain, nausea, vomiting, and swelling around the eyes and on the hands.
Relapsing Fever is a bacterial disease that is also carried by black-legged ticks. Its symptoms include fever, chills fatigue, severe headache, and muscle and joint pain. If contracted during pregnancy, it can cause premature birth and low birth weight, and in severe cases can cause miscarriage and death in newborns.
The Centers for Disease Control and Prevention has a great deal of information on ticks, tick bites, and tick-borne diseases at its website, https://www.cdc.gov/ticks/index.html.
Another excellent resource is the University of Rhode Island’s TickSmart Prevention page. https://web.uri.edu/tickencounter/ticksmart/.