Ehrlichiosis is the general name used to describe diseases caused by the bacteria Ehrlichia chaffeensis, E. ewingii, or E. muris eauclairensis in the United States. These bacteria are spread to people primarily through the bite of infected ticks including the lone star tick (Amblyomma americanum) and the blacklegged tick (Ixodes scapularis).

People with ehrlichiosis will often have fever, chills, headache, muscle aches, and sometimes upset stomach. Doxycycline is the treatment of choice for adults and children of all ages with ehrlichiosis.

Ehrlichiosis is the general name used to describe diseases caused by the bacteria Ehrlichia chaffeensis, E. ewingii, or E. muris eauclairensis in the United States. The majority of reported cases are due to infection with E. chaffeensis.

• Tick bites
  • Most people get ehrlichiosis from the bite of an infected tick.
  • In the United States, E. chaffeensis and E. ewingii are carried by the lone star tick (A. americanum), found primarily in the south-central and eastern United States.
  • E. muris eauclairensis is carried by the blacklegged tick (I. scapularis). While the blacklegged tick is widely distributed in the eastern United States, E. muris eauclairensis has only been found in Wisconsin and Minnesota.
• Blood transfusion and organ transplant
  • In rare cases, Ehrlichia species have been spread through blood transfusion and organ transplant.

Ehrlichiosis caused by E. chaffeensis and E. ewingii is most frequently reported from the southeastern and south-central United States, from the East Coast extending westward to Texas.

• Signs and symptoms of ehrlichiosis typically begin within 1-2 weeks after the bite of an infected tick.
  • Tick bites are usually painless, and many people do not remember being bitten.
• See your healthcare provider if you become ill after being bitten by a tick or spending time in grassy, brushy, wooded areas.

Early Illness

Early signs and symptoms (the first 5 days of illness) are usually mild or moderate and may include:

• Fever, chills
• Severe headache
• Muscle aches
• Nausea, vomiting, diarrhea, loss of appetite
• Confusion
• Rash (more common in children)

Rash

Up to 1 in 3 people with ehrlichiosis report a rash; rash is more common in people with E. chaffeensis ehrlichiosis and generally occurs more often in children than adults. Rash usually develops 5 days after fever begins. If a person develops a rash, it can look like red splotches or pinpoint dots.

Late Illness

If antibiotic treatment is delayed, ehrlichiosis can sometimes cause severe illness. Early treatment can reduce your risk of developing severe illness.

Signs and symptoms of severe (late stage) illness can include:

• Damage to the brain or nervous system (e.g. inflammation of the brain and surrounding tissue (called meningoencephalitis))
• Respiratory failure
• Uncontrolled bleeding
• Organ failure
• Death

Risk factors for severe illness:

• Delayed antibiotic treatment
• Age: being very young or very old
• Weakened immune system: such as those receiving some cancer treatments, individuals with advanced HIV infection, people who have received organ transplants, or people taking certain medications

Your healthcare provider can order certain blood tests to look for evidence of ehrlichiosis or other illnesses that can cause similar symptoms.

Test results may take several weeks.

If your healthcare provider thinks you have ehrlichiosis or another tickborne infection, he or she may prescribe antibiotics while you wait for test results.

Early treatment with the antibiotic doxycycline can prevent death and severe illness.

Doxycycline is the recommended antibiotic treatment for ehrlichiosis in adults and children of all ages.

• There is no vaccine to prevent ehrlichiosis. Prevent illness by preventing tick bites, preventing ticks on your pets, and preventing ticks in your yard.
• Ticks live in grassy, brushy, or wooded areas, or even on animals, so spending time outside camping, gardening, or hunting will bring you in close contact with ticks. Protect yourself, your family, and your pets. Here’s how:
• Ticks can be active year-round, but ticks are most active during warmer months (April-September).

Tick exposure can occur year-round, but ticks are most active during warmer months (April-September). Know which ticks are most common in your area.

Before You Go Outdoors

• Know where to expect ticks. Ticks live in grassy, brushy, or wooded areas, or even on animals. Spending time outside walking your dog, camping, gardening, or hunting could bring you in close contact with ticks. Many people get ticks in their own yard or neighborhood.
• Treat clothing and gear with products containing 0.5% permethrin. Permethrin can be used to treat boots, clothing and camping gear and remain protective through several washings. Alternatively, you can buy permethrin-treated clothing and gear.
• Use Environmental Protection Agency (EPA)-registered insect repellents containing DEET, picaridin, IR3535, Oil of Lemon Eucalyptus (OLE), para-menthane-diol (PMD), or 2-undecanone. EPA’s helpful search toolexternal icon can help you find the product that best suits your needs. Always follow product instructions. Do not use products containing OLE or PMD on children under 3 years old.
• Avoid Contact with Ticks
  • Avoid wooded and brushy areas with high grass and leaf litter.
  • Walk in the center of trails.

After You Come Indoors

Check your clothing for ticks. Ticks may be carried into the house on clothing. Any ticks that are found should be removed. Tumble dry clothes in a dryer on high heat for 10 minutes to kill ticks on dry clothing after you come indoors. If the clothes are damp, additional time may be needed. If the clothes require washing first, hot water is recommended. Cold and medium temperature water will not kill ticks.

Examine gear and pets. Ticks can ride into the home on clothing and pets, then attach to a person later, so carefully examine pets, coats, and daypacks.

Shower soon after being outdoors. Showering within two hours of coming indoors has been shown to reduce your risk of getting Lyme disease and may be effective in reducing the risk of other tickborne diseases. Showering may help wash off unattached ticks and it is a good opportunity to do a tick check.

Check your body for ticks after being outdoors. Conduct a full body check upon return from potentially tick-infested areas, including your own backyard. Use a hand-held or full-length mirror to view all parts of your body. Check these parts of your body and your child’s body for ticks:

• Under the arms
• In and around the ears
• Inside belly button
• Back of the knees
• In and around the hair
• Between the legs
• Around the waist