Ehrlichiosis – Symptoms and Causes
Overview
Ehrlichiosis and anaplasmosis are tick-transmitted diseases that share similar symptoms resembling the flu. These include fever, headaches, and muscle pain that typically develop within 14 days after a tick bite.
Quick treatment with appropriate antibiotics usually leads to recovery within days. However, without proper treatment, these infections can become serious or even life-threatening.
Symptoms
Ehrlichiosis and anaplasmosis share many symptoms, though ehrlichiosis typically causes more severe effects.
Common symptoms include:
- Fever (often sudden and high)
- Chills
- Headache
- Muscle aches
- General feeling of unwellness
- Joint pain
- Digestive problems (nausea, vomiting, diarrhea)
- Reduced appetite
Additional symptoms more commonly seen with ehrlichiosis:
- Mental confusion or difficulty concentrating
- Changes in thinking or alertness
- Skin rash (more common in children and with Ehrlichia chaffeensis)
Other less common symptoms that may occur:
- Cough
- Sensitivity to light (photophobia)
- Swollen lymph nodes
Some people, especially those who are older or immunocompromised, may develop more serious illnesses. Others may have mild symptoms or none at all.
When to Get Medical Help
Most people start showing signs 5-14 days after a tick bite. If you notice any symptoms after being bitten by a tick or spending time in areas where ticks live, you should contact your doctor right away.
Causes
Ehrlichiosis and anaplasmosis are caused by bacteria transmitted primarily through tick bites. These small arachnids attach to human skin and feed on blood, often for hours. During feeding, they can pass bacteria into the bloodstream—usually after 24 hours of attachment.
Different ticks spread these bacteria in specific regions, and their presence varies by region:
| Infection | Main Carrier | Primary Regions |
|---|---|---|
| Ehrlichiosis | Lone Star tick | South-central, southeastern, eastern coastal states |
| Anaplasmosis | Deer tick | Upper Midwest, northeastern states, central Canada |
The Lone Star tick is the main source of ehrlichiosis, especially in the southeastern U.S.
Anaplasmosis is most often spread by deer ticks (Ixodes scapularis in the east, and Ixodes pacificus in the west). Related ticks in Europe and Asia can also carry similar strains of these bacteria.
Both ehrlichiosis and anaplasmosis bacteria target immune system cells, though they may focus on different cell types. This explains why symptoms appear similar despite being caused by different bacteria.
Other Transmission Methods
Though tick bites are the main way these infections spread, other methods exist:
- Blood transfusions from infected donors
- During pregnancy from mother to baby
- Direct contact with infected animals, especially when handling slaughtered animals
Risk Factors
Several factors can raise your chances of getting tick bites:
- Seasonal Exposure: Being outside during warm spring and summer months when ticks are most active.
- Location: Spending time in wooded or brushy areas where ticks live near the ground.
- Activities: Camping, hiking, or hunting in areas with tall grass or dense vegetation.
- Clothing Choices: Wearing shorts, short-sleeved shirts, or other clothes that leave skin exposed in areas where ticks are common.
Remember that ticks cannot fly or jump. They can only attach to a host who directly brushes against them.
Complications
Without quick treatment, ehrlichiosis and anaplasmosis can cause serious problems in healthy people. Those with weak immune systems face even greater risks.
Untreated infections may lead to:
- Kidney failure
- Breathing problems
- Heart failure
- Brain and nerve damage
- Seizures
- Coma
- Serious secondary infections
Staying Safe from Ticks
Tick Protection Products
Ticks can be dangerous carriers of disease. When spending time outdoors, use repellents to keep ticks away from you.
Apply products with 0.5% permethrin to your clothes, shoes, tent, and other outdoor gear. Some outdoor clothing comes pre-treated with permethrin.
For your skin, use EPA-registered repellents containing ingredients like DEET, picaridin, IR3535, oil of lemon eucalyptus, para-menthane-diol, or 2-undecanone.
Apply to all exposed skin except your face. Remember that products with oil of lemon eucalyptus or para-menthane-diol should not be used on children younger than 3 years old.
Protective Clothing
What you wear can be your first defense against ticks. Choose light-colored clothes that make ticks easier to spot before they bite.
Wear closed shoes or boots instead of sandals or open-toed footwear.
Keep your body covered by wearing:
- Long-sleeved shirts tucked into pants
- Long pants tucked into socks
- A hat for head protection
This layering approach creates barriers that make it harder for ticks to reach your skin.
Tick Checks and Removal
After being outdoors, check your body thoroughly for ticks. Take a shower as soon as possible to wash away any loose ticks and make it easier to find attached ones.
Areas to check carefully:
- Underarms
- Hair and hairline
- Ears
- Waistline
- Between legs
- Behind knees
- Inside belly button
Use a mirror to see hard-to-view areas. Don’t forget to inspect your outdoor gear and clothes too. Put clothing in a hot dryer for at least 10 minutes to kill any ticks before washing.
Additional Safety Measures
If you have pets that go outside, check them daily for ticks. Pets can bring ticks into your home. These ticks could later attach to you or family members.
When hiking or working outdoors, stay on clear paths whenever possible. Ticks often wait on tall grass and brushy areas, ready to grab onto passing people or animals.
Walking in the center of trails helps reduce your contact with vegetation where ticks may be waiting.
Ticks typically climb upward after attaching. So, they often start at lower legs before finding a place to bite. Being aware of this behavior can help you catch ticks before they bite.
