What Is Anaplasmosis?

Learn how to tell the difference between anaplasmosis and Lyme disease, and when you should seek treatment.

Chances are, if you're spending a lot of time outdoors, you'll likely encounter a few bumps in the road health-wise. The occasional sunburned shoulder, a poison ivy rash on your ankle, and mosquito bites. In regions with lots of hiking trails in wooded areas, you should probably add tick bites to that list of offenders to be aware of and protect against.

While you likely associate ticks with Lyme disease, other health conditions can result from a bite. Tick bites can also cause a less common—but potentially serious—infection called anaplasmosis. 

Here's what you should know about anaplasmosis symptoms, treatments, and prevention methods.

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What Is Anaplasmosis?

Previously known as human granulocytic ehrlichiosis (HGE), anaplasmosis is an illness caused by the bacterium Anaplasma phagocytophilum. The culprit carrying that bacterium is blacklegged ticks, also known as deer ticks, which also carry the bacterium that causes Lyme disease.

Anaplasmosis was only recognized as a human disease in the United States during the mid-1990s. The illness became reportable to the Centers for Disease Control and Prevention (CDC) in 1999, and the agency noted 348 cases in 2000. However, that number steadily grew, hitting more than 5,000 cases in 2019.

Anaplasmosis infections have been reported in various regions of the country. However, blacklegged ticks are most commonly found in the Northeast and northern areas of the Midwest.

Anaplasmosis Symptoms 

If an infected blacklegged tick bites you, anaplasmosis symptoms usually begin within one to two weeks. Generally, the illness occurs in two phases. Early illness occurs from days one to five, followed by late illness.

Symptoms that commonly occur during early illness include:

  • Fever
  • Chills
  • Muscle aches
  • Severe headache
  • Vomiting
  • Diarrhea
  • Nausea
  • Loss of appetite

If you develop those symptoms, the CDC recommends seeing a healthcare provider if any of the following recently occurred:

  • A tick bit you.
  • You were in the woods.
  • You visited areas with a high brush where ticks typically live.

You risk developing severe illness, which can become fatal if you don't receive treatment early. Though, it's rare to die from anaplasmosis. Symptoms of late illness commonly include:

  • Respiratory failure
  • Organ failure
  • Bleeding problems
  • Death

Differences Between Anaplasmosis and Lyme Disease

Some symptoms of anaplasmosis overlap with those of Lyme disease, Purvi Parikh, MD, an infectious disease specialist at NYU Langone, told Health.

However, there are a few differences. For one thing, people with anaplasmosis commonly experience diarrhea, vomiting, and nausea. However, those symptoms are less common with Lyme disease, said Dr. Parikh. 

People with anaplasmosis are also more likely to have respiratory problems than people with Lyme disease, added Dr. Parikh.

Lyme disease can also cause a rash that looks like a target mark with a red ring encircling the spot where the tick bit, which isn't typical with anaplasmosis.

How Is Anaplasmosis Diagnosed?

A healthcare provider can use a blood test to know whether you have anaplasmosis. Although results may take a couple of weeks, a healthcare provider will likely begin treating you immediately.

While keeping the tick in a plastic bag to show to a healthcare provider certainly can't hurt, it might not end up doing you any good, said Dr. Parikh. "It can be helpful, but I don't know enough about how the ticks look," noted Dr. Parikh. "I would still order the bloodwork [to confirm the diagnosis]."

How To Treat Anaplasmosis

The number of people who die due to an anaplasmosis infection is low. According to the CDC, less than 1% of people with anaplasmosis die in the United States due to their symptoms.

Still, consulting a healthcare provider after you first notice symptoms is essential to prevent progressing to late illness. With anaplasmosis, a healthcare provider may prescribe doxycycline, an antibiotic.

"People respond [to doxycycline] rather quickly. Within 48 hours, [they're] feeling better, temperature's going away," Alan Taege, MD, an infectious disease specialist at Cleveland Clinic, told Health. 

A healthcare provider might prescribe more intensive treatments for those who delay seeking treatment. Late illness may require hospitalization in the intensive care unit (ICU) if the infection progresses into organ failure or other severe symptoms, said Dr. Parikh.

How To Prevent Anaplasmosis

There are many ways to keep yourself safe from ticks and tick-borne illnesses like Lyme disease and anaplasmosis. For example, the CDC recommends doing the following to avoid tick bites:

  • Educating yourself on where ticks can be found (like grassy, brushy, or wooded areas)
  • Avoiding contact with ticks by not going to wooded or brushy areas with high grass and walking in the center of trails
  • Applying gear and clothing with products containing 0.5% permethrin
  • Using insect repellants registered with the Environmental Protection Agency (EPA)

Tucking your pant legs into your shoes and wearing lighter-colored clothing so that you can see ticks, which are darker-colored, may help, recommended Dr. Taege.

When you return from outdoor activities, ensure that ticks aren't on your body or clothing. The CDC suggests taking the following steps:

  • Check your clothing for ticks.
  • Examine gear and pets.
  • Shower within two hours.
  • Check your or your child's body (armpits, ears, belly button, back of the knees, hair, waist, and between the legs) with a hand-held or full-length mirror.

If you notice a tick, take steps to properly remove it, so you don't cause infection.

A Quick Review

Anaplasmosis is a bacterial infection that transmits through the bites of infected blacklegged ticks. Most commonly, anaplasmosis causes fever, chills, vomiting, and diarrhea. A blood test can determine if you have the illness, and antibiotics usually clear up any symptoms.

If untreated, serious complications, such as organ failure or bleeding problems, may occur and require hospitalization. 

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Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Anaplasmosis.

  2. Centers for Disease Control and Prevention. Epidemiology and statistics.

  3. Centers for Disease Control and Prevention. Signs and symptoms.

  4. Centers for Disease Control and Prevention. Diagnosis and testing.

  5. National Library of Medicine. Doxycycline.

  6. Centers for Disease Control and Prevention. Anaplasmosis prevention.

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