Ehrlichiosis

Ehrlichiosis refers to a group of diseases caused by bacteria called Ehrlichia.  The various Ehrlichia bacteria are carried by species of ticks such as the lone star tick, commonly found throughout Missouri.  Humans typically become infected with Ehrlichia following the bite of an infected tick.  In the United States, human ehrlichiosis was first recognized in the mid-1980s.  Ehrlichiosis is currently second to only Rocky Mountain spotted fever as the most commonly reported tick-borne illness in Missouri.

The first symptoms of ehrlichiosis generally include a sudden onset of fever, headache, and muscle aches typically within 5-10 days following a tick bite.  Other signs and symptoms may include nausea, vomiting, diarrhea, cough, joint pains, confusion, and occasionally a rash.  The initial symptoms are similar to Rocky Mountain spotted fever except, rash is relatively uncommon in adults.  However, a rash has been reported in over half of children with the disease.  It is important to note that some persons with ehrlichiosis do not even recall being bitten by a tick.       

Initial signs and symptoms:

• fever
• headache
• muscle aches
• nausea
• vomiting
• diarrhea
• lack of appetite

The disease can be difficult to diagnose in the early stages, and may range from a mild illness to a more severe and even fatal condition.  Persons with ehrlichiosis generally visit a physician in the first week of their illness.  Appropriate antibiotic treatment should be initiated immediately when ehrlichiosis is suspected as the cause of illness.  Fever generally improves within 24-72 hours after treatment with an appropriate treatment (usually doxycycline).  Although ehrlichiosis can be severe, preventive therapy in non-ill persons following a tick bite is not recommended.

The DHSS Bureau of Communicable Disease Control and Prevention records the number of human ehrlichiosis cases in Missouri every year in an Annual Report of the Bureau’s surveillance, investigation, and prevention activities.

The best way to prevent getting ehrlichiosis is to avoid getting bitten by ticks.  Therefore, prevention measures should emphasize personal protection when exposed to areas where ticks are present:

• Wear light-colored clothing to make ticks easier to see.  Wear long pants and tuck the pants legs into your socks so that ticks cannot crawl up the inside of your pants legs.
• For adults, use insect repellents containing 20-50% DEET on your skin.  The American Academy of Pediatrics has recommended that repellents containing up to 30% DEET can be used on children over 2 months of age.
• For clothing, permetherin or DEET may be used.
• Be sure to follow the directions on the permetherin or DEET containers and wash off repellents when going indoors.  Carefully read the manufacturer’s label on repellents before using, especially on children.
• Conduct body checks regularly and upon return from potentially tick-infested areas by searching your entire body for ticks. Use a hand-held or full-length mirror to view all parts of your body.
• Parents should check their children for ticks, especially in the hair, when returning from potentially tick-infested areas. Ticks may also be carried into the household on clothing and pets and only attached later so both should be examined carefully to exclude the ticks.

If a tick is attached, it is important the tick be removed promptly.  Immediate removal of ticks using methods listed below may also reduce your risk of developing ehrlichiosis and other tick-borne illnesses.

• Use fine-tipped tweezers and protect your fingers with a tissue, paper towel, or latex gloves. Avoid removing ticks with your bare hands.
• Grasp the tick as close to the skin surface as possible and pull upward with steady, even pressure. Do not twist or jerk the tick; this may cause the mouthparts to break off and remain in the skin. (If this happens, remove mouthparts with tweezers. Consult your health care provider if illness occurs.)
• DO NOT squeeze, crush, or puncture the body of the tick at any time while it is attached.  This could force the disease causing bacteria from the tick into the bite wound.
• DO NOT squeeze the body of the tick to kill it after it has been removed.  This could result in the disease causing bacteria to get onto/into your skin.
• After removing the tick, thoroughly disinfect the bite site and wash your hands with soap and water.
• DO NOT use matches, gasoline, nail polish remover, or other ointments to remove the tick.  This could cause the tick to release additional saliva containing the disease causing bacteria into the bite wound.
• Inspect your body for additional ticks – don’t forget the hard to see areas including the scalp.
• Note the date of the tick bite and consult your health care provider if you develop any symptoms consistent with ehrlichiosis. 

Please contact your health care provider, local health department, or the Department of Health and Senior Services (866-628-9891) if you have other questions about ehrlichiosis.