Anaplasmosis is an illness spread by ticks.
In Wisconsin, it is spread by the deer tick, also known as the black-legged tick.
Anaplasmosis is caused by the bacterium Anaplasma phagocytophilum.
Anyone can get anaplasmosis. People who spend more time outdoors are at a higher risk of being bitten by an infected tick.
Ticks are commonly found in areas with woods, brush, or tall grass. Ticks are most active from May to November, but it’s important to use caution year-round.
Anaplasmosis is spread to humans through the bite of an infected deer tick.
To prevent illness, it’s important to remove ticks as soon as you find them. A tick must be attached for at least 12–24 hours to spread anaplasmosis to a person.
Most people are infected by immature ticks, called nymphs. Nymphs are very small, about the size of a poppy seed. They’re hard to see. Most people don’t feel their bites. This makes them harder to remove right away. Nymphs are most active during the spring and early summer.
Adult ticks also spread anaplasmosis. Adults are larger than nymphs. They’re more likely to be found and removed before the bacteria spread to the person. The image to the right shows an adult deer tick. Adult ticks are most active during the cooler months in early spring and fall.
Ticks can attach to any part of the body. They often are found in hard-to-see areas, such as:
- Behind the knees.
- In the armpits.
- On the scalp.
- In and around the ears.
- Inside the belly button.
- On the groin.
Anaplasmosis is preventable and treatable. Learn about Tick Bite Prevention and how to properly remove a tick if you’re bitten.
Symptoms can show up one to two weeks after being bitten by an infected tick.
The following symptoms can be seen with anaplasmosis. However, few people will have all the symptoms listed. The combination of symptoms varies for each person.
Early signs and symptoms are usually mild. However, more severe symptoms can occur if antibiotic treatment is delayed. Severe symptoms are rare, but it’s important to get treatment as soon as possible.
Early signs and symptoms:
- Severe headache
- Muscle aches
- Nausea, vomiting, diarrhea
Late signs and symptoms:
- Respiratory failure
- Organ failure
Anaplasmosis can be treated with antibiotics. Doxycycline is the antibiotic of choice for adults and children of all ages. Treatment should begin as soon as anaplasmosis is suspected. Most people treated with oral antibiotics during the early stages of anaplasmosis fully recover.
It’s important to get treatment as soon as possible after symptoms start.
Treatment recommended by the CDC (Centers for Disease Control and Prevention)
|Age Category||Drug||Dosage||Maximum||Duration, Days|
|Adults||Doxycycline||100 mg, twice per day||100 mg/dose||7–14|
|Children under 45 kg (100 lbs)||Doxycycline||2.2 mg/kg body weight, twice per day||100 mg/dose||7–14|
Antibiotic treatment following a tick bite isn’t recommended to prevent anaplasmosis. There is no evidence this practice is effective, and it may only delay onset of the disease. Instead, if you’re bitten by a tick, be alert for the symptoms listed above. Call a doctor if you develop a fever or other symptoms.
- Signs and symptoms, treatment, and prevention—Anaplasmosis and Ehrlichiosis Fact Sheet, P-42045
- Education on the risk posed by illnesses spread by ticks—Tickborne Diseases Risk in Wisconsin, P-01751 (PDF)
- Educational tri-fold card about Wisconsin, proper tick removal, and tick bite prevention—Tick Safety Guide Tri-Fold Card, P-01434
- Fact sheet with simple steps to take—Protecting Your Family From Mosquitoes and Ticks, P-02080
Resources from the CDC
- Signs and symptoms, treatment, prevention, and more—CDC Anaplasmosis Page
- Preventing Ticks on Your Pets
- Fact sheet on tick bite prevention for hunters—It's Open Season on Ticks
- Plastic trail sign used to remind hikers that there are ticks in the area—Prevent Tick Bites (PDF). Order the sign from CDC Info on Demand.
- Bookmark—Prevent Lyme Disease and How to Remove a Tick—Order the bookmark from CDC Info on Demand
- Educational comic for kids—Don't Let a Tick Make You Sick Comic (PDF)
- Educational crossword for kids—Don't Let a Tick Make You Sick Crossword (PDF)
Questions about illnesses spread by ticks? We’re here to help.
Bureau of Communicable Diseases