Anaplasmosis

What is anaplasmosis?

Anaplasmosis is a tickborne disease caused by the bacterium Anaplasma phagocytophilum.

Who gets anaplasmosis?

Any person that is bitten by an infected blacklegged tick can get this disease.

How is anaplasmosis spread?

This pathogen is transmitted to people by the bite of an infected blacklegged tick (Ixodes scapularis). This tick and disease are seen primarily in the eastern United States. The western blacklegged tick (Ixodes pacificus) is the primary vector along the West Coast. In rare situations, anaplasmosis has been spread by blood transfusion.

What are the symptoms of anaplasmosis?

The common symptoms of anaplasmosis are a rapid onset of fever accompanied by one or more of the following symptoms: headache, body aches, diarrhea, nausea, vomiting or loss of appetite. Rare symptoms include rash or nervous system involvement. If treatment is delayed or patients do not receive care, they may develop serious disease, including renal or respiratory failure. It is important to note that few people with the disease will develop all symptoms. The number and combination of symptoms varies greatly from person to person, however, those younger than five years old, older than 65 years of age or persons with immune compromising conditions are at a higher risk for developing severe disease.

How soon after exposure do symptoms appear?

The first symptoms of anaplasmosis typically begin within 1–2 weeks after the bite of an infected tick. The tick bite from a blacklegged tick is painless and causes no itch, so many patients who develop anaplasmosis do not remember being bitten by a tick.

How is anaplasmosis diagnosed?

The diagnosis of anaplasmosis must be based on clinical signs and symptoms and can later be confirmed using specialized confirmatory laboratory tests. Testing for anaplasmosis should be considered for any person with a compatible illness, especially in endemic regions and for those with known risk factors, such as history or a tick bite or exposure to tick habitat.

What is the treatment for anaplasmosis?

Doxycycline is the recommended antibiotic treatment for adults and children of all ages and should be initiated as soon as anaplasmosis is suspected. Use of antibiotics other than doxycycline or other tetracyclines has been associated with a higher risk of fatal outcome for some rickettsial infections. Doxycycline is most effective at preventing severe illness complications if it is started early in the course of disease.

How can anaplasmosis be prevented?

Avoid tick habitats, such as leaf litter, grass and vegetation in forests, and shaded areas, along forest edges. If you do spend time outdoors in such tick habitats, including your backyard, take precautions to keep ticks off the skin. Walk on cleared trails and stay in the center of the trail to avoid contact with leaf litter or low vegetation. If you visit potential tick habitats, a highly effective tick prevention method is to wear long pants, socks and shoes or boots that have been treated with a “Permethrin” based clothing treatment; pants legs should be tucked into socks and/or into boots. Wear light-colored clothing so that ticks are easier to see and remove. If wearing shorts, apply tick repellent containing DEET, oil of lemon eucalyptus or picaridin on your skin around your knees and around your elbows. Conduct tick checks on yourself, your children, and your pets after spending time in an area likely to have ticks.

How can I get more information about anaplasmosis?

• If you have concerns about anaplasmosis, contact your healthcare provider.
• Call your local health department. You can find your local health department at vdh.virginia.gov/health-department-locator/.
• Visit the CDC's page on anaplasmosis at cdc.gov/anaplasmosis/about/index.html.