Anaplasmosis and Ehrlichiosis: Tick-borne Bacterial Infections

Updated: October 2011

What are anaplasmosis and ehrlichiosis?

Anaplasmosis and ehrlichiosis are tick-borne diseases that can be caused by two different bacteria. Ehrlichiosis is caused by Ehrlichia chaffeensis, which is transmitted by the lone star tick (Amblyomma americanum). Anaplasmosis, previously known as human granulocytic ehrlichiosis (HGE), is caused by Anaplasma phagocytophilia, which is transmitted by the deer tick (Ixodes scapularis). In New York State, most cases have been reported on Long Island and in the Hudson Valley.

Who gets anaplasmosis and ehrlichiosis?

Anyone can get anaplasmosis or ehrlichiosis, although the majority of known cases have been in adults. People who spend time outdoors in tick-infested areas from April until October are at greatest risk for exposure.

How are the bacteria transmitted?

The bacteria that cause these diseases are transmitted by the bite of infected deer or lone star ticks. Neither are spread from person to person.

What are the symptoms of anaplasmosis and ehrlichiosis

The symptoms are the same and usually include fever, muscle aches, weakness and headache. Patients may also experience confusion, nausea, 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.

When do symptoms appear?

Symptoms appear one to three weeks after the bite of an infected tick. However, not every exposure results in infection.

What is the treatment?

Tetracycline antibiotics are usually rapidly effective for ehrlichiosis. Because these antibiotics can cause dental staining in children, physicians should consult an infectious disease expert when treating children.

What can be done to prevent tick-borne infections like anaplasmosis and ehrlichiosis?

A thorough check of body surfaces for attached ticks should be done when leaving tick habitat, and again at the end of the day. 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.

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. After removing the tick, thoroughly disinfect the bite site and wash hands. 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.