What Is Ehrlichiosis?

Ehrlichiosis is a bacterial disease transmitted to people by the Lone Star tick, the deer tick, or the Dog tick.

What are the symptoms?

The following is a list of symptoms commonly seen with this disease; however, it is important to note that the combination of symptoms varies greatly from person to person.

  • Fever
  • Headache
  • Chills
  • Malaise
  • Muscle pain
  • Nausea / Vomiting / Diarrhea
  • Confusion
  • Conjunctival injection (red eyes)
  • Rash (in up to 60% of children, less than 30% of adults)

Ehrlichiosis is a serious illness that can be fatal if not treated correctly, even in previously healthy people. Severe clinical presentations may include difficulty breathing, or bleeding disorders. The estimated case fatality rate (i.e. the proportion of persons who die as a result of their infection) is 1.8%. Patients who are treated early may recover quickly on outpatient medication, while those who experience a more severe course may require intravenous antibiotics, prolonged hospitalization or intensive care.

Physician Diagnosis

There are several aspects of ehrlichiosis that make it challenging for health care providers to diagnose and treat. The symptoms vary from patient to patient and can be difficult to distinguish from other diseases. Treatment is more likely to be effective if started early in the course of disease. Diagnostic tests based on the detection of antibodies will frequently be negative in the first 7-10 days of illness.

For this reason, health care providers must use their judgment to treat patients based on clinical suspicion alone. Health Care providers may find important information in the patient's history and physical examination that may aid clinical suspicion. Information such as recent tick bites, exposure to areas where ticks are likely to be found, or history of recent travel to areas where ehrlichiosis is endemic can be helpful in making the diagnosis. The health care provider should also look at routine blood tests, such as a complete blood cell count or a chemistry panel. Clues such as a low platelet count (thrombocytopenia), low white blood cell count (leukopenia), or elevated liver enzyme levels are helpful predictors of ehrlichiosis, but may not be present in all patients depending on the course of the disease. After a suspect diagnosis is made on clinical suspicion and treatment has begun, specialized laboratory testing should be used to confirm the diagnosis of ehrlichiosis.

How is Ehrlichiosis treated?

If you have a fever or rash within 7-8 days after a tick bite, consult your physician. It's important to note on a calendar the date a person was bitten by a tick. Most people can be successfully treated with antibiotics if treatment is begun immediately following suspicion of a possible infection.

How do people catch this disease?

Ehrlichiosis cannot be transmitted from person to person. The Lone Star tick, the dog tick and the deer tick can all transmit the disease. White tailed deer, dogs and small rodents may be hosts for the disease. Transmission of the bacteria from an infected tick most often occurs after a tick has been attached and feeding for 36 hours.

What can be done to stop the spread of this disease?

Ticks live in woods, brushy areas, and areas with tall grass and weeds. Children who play on uncleared land or in brush or weeds should be checked closely at least twice a day, especially in the hair where ticks are hard to see. Adults should also examine themselves after being involved in similar outdoor activities. Ticks must be removed as soon as possible to prevent the transmission of possible disease pathogens. Bathe or shower and shampoo hair after outdoor activities to prevent the attachment of ticks.

If found, ticks should be pulled out with tweezers or with fingers covered by a piece of tissue or paper towel. Ticks should not be jerked or twisted, but pulled out with a steady motion. The use of heat, solvents, nail polish, Vaseline or other material to cause the tick to release is not advised. Antiseptic should be applied to the bite area and hands washed with soap and water. Remember to mark the date on your calendar that the tick was found.

General precautions can help prevent tick bites. These include using an insect repellent that can be sprayed on clothes as well as a repellent that can be used on exposed skin. Follow label directions and use extra precautions for children. Other precautions include wearing protective, light-colored clothing tucked in around the ankles and waist, keeping weeds and tall grass cut, and avoiding tick-infested places such as grassy and marshy woodland areas when possible. Stay in the center of paths when hiking or walking through woods.

Pets should be checked for ticks at least once a week, and tick collars, shampoos and other tick repellents are recommended. Oral and topical medications are also available from veterinarians.

References and Additional Information


Health Infectious Diseases