Anaplasmosis and Ehrlichiosis: Tick-borne Bacterial Infections

Reviewed: November 2016

What are Anaplasmosis and Ehrlichiosis?

Anaplasmosis and Ehrlichiosis are two closely related tick-borne bacterial diseases spread by the bite of infected ticks. Anaplasmosis, formerly called human granulocytic ehrlichiosis (HGE), is spread to humans by blacklegged deer ticks infected with the bacterium, Anaplasma phagocytophilia. Ehrlichiosis, or human monocytic ehrlichiosis (HME), is spread to humans by lone star ticks infected with the bacterium, Ehrlichia chaffeensis. In New York State, most cases have been reported on Long Island and in the Hudson Valley.

Who gets Anaplasmosis and Ehrlichiosis?

Anaplasmosis or Ehrlichiosis can affect people of any age. Neither disease is spread from person to person. People who spend time outdoors hiking, working, or playing, particularly in grassy and wooded areas from April until October are at greatest risk for exposure. Ticks can be active any time the temperature is above freezing.

What are the symptoms of Anaplasmosis and Ehrlichiosis?

The symptoms are the same for both and may include fever, muscle aches, weakness, and headache. Patients may also experience confusion, nausea (the feeling of sickness in the stomach), vomiting, and joint pain. Unlike Lyme disease or Rocky Mountain spotted fever, a rash is not common. Infection usually produces mild to moderately severe illness, with high fever and headache, but may occasionally be life threatening or even fatal. Symptoms appear one to two weeks after the bite of an infected tick. However, not every bite from an infected tick results in infection.

How are Anaplasmosis and Ehrlichiosis diagnosed?

Symptoms and possible tick bite exposure may cause a health care professional to suspect one of these infections. Laboratory tests confirm diagnosis by seeing if the bacteria or antibodies against the bacteria are present in the person.

What is the treatment?

Tetracycline antibiotics are usually rapidly effective for these infections. Because these antibiotics can cause dental staining in children, physicians should consult an infectious disease expert when treating children. Treatment should not be delayed while waiting for a laboratory confirmation of diagnosis.

Does past infection make a person immune?

Anaplasmosis and Ehrlichiosis are bacterial infections. Even if successfully treated, a person may become re-infected if bitten later by another infected tick.

What can be done to prevent tick-borne infections like Anaplasmosis and Ehrlichiosis?

Generally, ticks cannot jump or fly onto a person. They wait in vegetation and cling to animals and humans when they brush by. Domestic animals can carry ticks into areas where you live such as your house or garage, so brush off animals and look for ticks before they enter these areas. The best prevention to either disease is through awareness. Check after every two to three hours of outdoor activity for ticks on clothing or skin. Brush off any ticks on clothing before skin attachment occurs. With anaplasmosis, if removal of attached ticks occurs within 12 hours the risk of tick-borne infection is minimal. For ehrlichiosis, if removal of attached ticks occurs within 36 hours the risk of tick-borne infection is minimal. For proper tick removal, please watch the video at Tick Removal.

Insect repellents can be effective at reducing bites from ticks that can spread disease. If you decide to use a repellent, use only what and how much you need for your situation. More information on repellents: Environmental Protection Agency- insect-repellents.

In addition:
  • Be sure to follow label directions.
  • Try to reduce the use of repellents by dressing in long sleeves and pants tucked into socks or boots.
  • Children should not handle repellents. Instead, adults should apply repellents to their own hands first and then gently spread on the child's exposed skin. Avoid applying directly to children's hands. After returning indoors, wash your child's treated skin and clothing with soap and water or give the child a bath.
  • Do not apply near eyes, nose or mouth and use sparingly around ears.
  • After returning indoors, wash treated skin with soap and water.
  • Domestic animals can carry ticks into areas where you live so it is important to check pets for ticks before they enter the home.

How should a tick be removed?

Grasp the mouthparts with tweezers as close as possible to the attachment (skin) site. Be careful not to squeeze, crush or puncture the body of the tick, which may contain infectious fluids. Pull firmly and steadily upward to remove the tick. After removing the tick, thoroughly disinfect the bite site and wash hands. The NYSDOH has created a video on proper tick removal (Proper Tick Removal) and a printable card with steps on how to remove ticks (How to Remove a Tick Card). See or call a doctor if there are concerns about incomplete tick removal. Do not attempt to remove ticks by using petroleum jelly, lit cigarettes or other home remedies because these may actually increase the chance of contracting a tick-borne disease.