For the Pacific Northwest, Northeast and upper Midwest, ticks have always been an unpleasant nuisance. However, the effects of climate change, including warmer temperatures and longer dry spells, are extending the season for tick-borne illnesses. According to the Center for Disease Control (CDC), cases of tick-borne illnesses have more than doubled in the last 20 years, with 50,865 cases reported in 2019.

Ticks use an ambush strategy to feed, waiting on the ends of tall grass for an animal to walk by so they can hitch a ride. As parasitic blood suckers throughout their three-stage life cycle (larvae, nymphs, and adults), they sense heat, carbon dioxide, vibrations, and odors to identify their hosts. However, ticks can live a year without food by slowing their metabolism (wild!). Check out the CDC’s Tick ID page for descriptions and photographs.

While many people are familiar with Lyme disease, it is only one of several tick-borne illnesses prevalent in North America. While prevention strategies are an integral part of minimizing your chances of contracting a tick-borne disease, knowing the signs and symptoms of potential illnesses is essential to diagnosing and managing them.

Geographical distribution of US tick-borne illnesses reported to the CDC in 2016.

Common tick-borne diseases:

1. Lyme disease: Caused by the spirochete Borrelia burgdorferi, Lyme disease is transmitted through the bite of infected black-legged deer ticks. It can lead to a range of symptoms, including fever, fatigue, headache, muscle and joint aches, and a characteristic target-like skin rash called erythema migrans.

2. Rocky Mountain spotted fever (RMSF): Transmitted in the US mostly by the American dog tick, RMSF is caused by the bacterium Rickettsia rickettsii. It can cause fever, headache, rash, abdominal pain, and in severe cases, organ damage or even death if not treated promptly.

Infected patients become symptomatic two days to two weeks after being bitten by an infected tick, with most cases occurring between five and seven days. A rash occurs in about 90 percent of patients, although it’s not typically seen at the very beginning. Most patients develop a rash between the third and fifth days of illness. The appearance of the rash usually begins on the ankles and wrists and spreads to the trunk; rash that appears on the palms and soles is highly characteristic of RMSF, but usually occurs in later-stage disease.

3. Ehrlichiosis: Mostly transmitted by the lone star tick. Ehrlichiosis can lead to flu-like symptoms such as fever, headache, muscle aches, and fatigue. Immunocompromised patients can often become much more ill.

4. Anaplasmosis: Anaplasmosis is caused by the bacterium Anaplasma phagocytophilum, which is transmitted by black-legged ticks and the western black-legged tick. It too typically presents with symptoms like fever, headache, muscle aches, and fatigue.

5. Babesiosis: Babesiosis is caused by microscopic parasites of the genus Babesia, which are transmitted mostly by black-legged ticks. Its symptoms can mimic those of malaria, including fever, fatigue, muscle aches, and in severe cases, complications involving the liver, spleen, or other organs.

Prevention strategies:

The main methods of preventing tick bites are wearing long-sleeved clothing, wearing clothing treated with permethrin (a repellent / insecticide), and using repellents such as DEET or picaridin. Performing tick checks is another strategy to find ticks early on. To properly check for ticks, it is essential to remove clothing for a visual inspection, methodically survey the body for any sign of ticks, and be especially vigilant in warmer places, such as knees, armpits, privates, head, neck and stomach.

Treatment:

If a tick is found, remove it immediately. The most effective method for pulling a tick out is using tweezers to grab the head/neck and draw it perpendicular from the skin with consistent pressure. According to Wilderness Medical Society, “Generally, the risk of Lyme disease transmission is correlated with the duration of tick attachment… The CDC recommends tick removal within 36 hours of attachment to reduce the risk of Lyme disease.” Ensure all parts of the tick were removed and wash the area with soap and water. Vaseline, heat, and nail polish are not recommended methods for removing ticks because there's a chance the tick regurgitates, causing infection.

When should you see a medical professional? If you suspect prolonged tick adherence, say beyond 36 hours, physicians can give prophylaxis, depending on local epidemiology. Or, if you are symptomatic with a known recent tick bite or outdoor activity that might have presented an exposure. Some sources recommend saving the tick for testing. However, from a practical standpoint, labs in California stopped taking ticks because of a backlog of untested arthropods. And, if the tick is positive for disease, it does not confirm transmission. Check your local or state health departments for their recommendation.

Leave us a comment below with your thoughts or experiences on tick-borne illnesses.

Tick Season—Yikes!