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?

When in tick-infested habitat - wooded and grassy areas - take special precautions to prevent tick bites, such as wearing light-colored clothing (for easy tick discovery) and tucking pants into socks and shirt into pants. 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. A thorough check of body surfaces for attached ticks should be done at the end of the day. If removal of attached ticks occurs within 36 hours, the risk of tick-borne infection is minimal.

Repellents can be effective at reducing bites from ticks that can transmit disease. But their use is not without risk of health effects, especially if repellents are applied in large amounts or improperly. Repellents commonly available to consumers contain the active ingredients DEET (N, N-diethyl-m-toluamide), picaridin (also known as KBR 3023), oil of lemon eucalyptus, permethrin, or botanical oils. DEET products have been widely used for many years, but have occasionally been associated with health effects. Skin reactions (particularly at DEET concentrations of 50 percent and above) and eye irritation are the most frequently reported health problems. Picaridin and oil of lemon eucalyptus have been shown to offer long-lasting protection against mosquitoes but there are limited data regarding their ability to repel ticks. Products containing permethrin are for use on clothing only, not on skin. Rather than acting as a repellent, permethrin kills ticks and insects that come in contact with treated clothes. Permethrin can cause eye irritation. Insect repellents containing botanical oils, such as oil of geranium, cedar, lemongrass, soy or citronella are also available, but there is limited information on their effectiveness and toxicity. If you decide to use a repellent, use only what and how much you need for your situation. In addition:

  • Be sure to follow label directions.
  • Use repellents only in small amounts, avoiding unnecessary repeat application. Try to reduce the use of repellents by dressing in long sleeves and pants tucked into socks or boots.
  • Children may be at greater risk for reactions to repellents, in part, because their exposure may be greater. Do not apply repellents directly to children. Apply to your own hands and then put it on the child.
  • Do not apply near eyes, nose or mouth and use sparingly around ears. Do not apply to the hands of small children.
  • After returning indoors, wash treated skin with soap and water.

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.