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by Jones P


Ehrlichiosis is an infection passed through a tick bite. It can be deadly unless medicine is taken to treat it.


Ehrlichiosis is caused by specific bacteria. The bacteria are passed through the bite of a tick. The lonestar tick, deer tick, and dog tick are linked with this infection.

Risk Factors

Things that may raise the risk of this infection are:

  • Being in areas known to have ticks
  • Spending time in the Mid-Atlantic, Southeastern, and Southcentral United States
  • Having a weakened immune system


It may take 1 to 2 weeks for symptoms to happen. The first symptoms are like the flu:

  • Fever
  • Chills
  • Muscle and joint aches
  • Headaches

Some people may also have a rash.

Headache and Neck Stiffness
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You will be asked about your symptoms and health history. You will be asked if you have spent time in areas known for ticks. A physical exam will be done.

A blood test may be done to check for signs of ehrlichiosis.


Ehrlichiosis is treated with antibiotics.


To lower the chance of this infection:

  • Avoid tick-infested areas.
  • Wear light-colored clothing to better locate a crawling tick.
  • Tuck pants into socks when in tick-infested habitats.
  • Regularly inspect and remove ticks from the body when in tick-infested habitats.
  • Remove ticks using fine-tipped tweezers by grasping the tick close to the skin’s surface and pulling upward steadily.
  • Disinfect tick bites with soap and water.
  • Use tick repellents.


Centers for Disease Control and Prevention  http://www.cdc.gov 

Family Doctor—American Academy of Family Physicians  http://familydoctor.org 


Health Canada  https://www.canada.ca/en/health-canada.html 

Public Health Agency of Canada  http://www.phac-aspc.gc.ca 


Biggs HM, Behravesh CB, et al. Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses, Ehrlichioses, and Anaplasmosis - United States. MMWR Recomm Rep. 2016 May 13;65(2):1-44.

Ehrlichiosis. American Academy of Family Physicians website. Available at: http://familydoctor.org/familydoctor/en/diseases-conditions/ehrlichiosis.html. Updated September 19, 2017. Accessed November 25, 2019.

Ehrlichiosis. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/ehrlichiosis. Updated January 17, 2019. Accessed November 25, 2019.

Ehrlichiosis and anaplasmosis. EBSCO DynaMed website. Available at:  https://www.dynamed.com/condition/ehrlichiosis-and-anaplasmosis . Updated December 9, 2016. Accessed November 25, 2019.

Revision Information

  • Reviewer: EBSCO Medical Review Board James P. Cornell, MD
  • Review Date: 09/2019
  • Update Date: 05/27/2020