A New Tick-Borne Disease on the Rise in Vermont

Molly Markowitz '18
Molly Markowitz ’18

Molly Markowitz ’18 has written about tick-borne disease for several publications, as well as presented a poster at the recent annual meeting of the Family Medicine Education Consortium.  This blog post first appeared in Health Source, the blog from The University of Vermont Medical Center, on December 16, 2015.

The results are in from the 2015 spring, summer, and fall tick season and the tick-borne disease, Anaplasmosis, is on the rise in Vermont. Many people may not be familiar with this emerging disease. I will answer some frequently asked questions.

What is Anaplasmosis?

A blacklegged or deer tick
A blacklegged or deer tick

Anaplasmosis is a bacterial infection that is transmitted to people through the bite of a blacklegged tick or deer tick. The tick must be infected with the bacteria Anaplasma phagocytophilum to transmit the disease. This is the same tick that can transmit Lyme disease to humans.

How many cases have been reported in Vermont?

The first two cases of locally-acquired Anaplasmosis in Vermont were reported in 2010. According to the Vermont Department of Health, there has been a significant increase in the number of cases over the past five years. To date in 2015, there have been 115 confirmed and probable cases in Vermont.

The number of confirmed and probable cases of Anaplasmosis in Vermont from 2010-2015.
The number of confirmed and probable cases of Anaplasmosis in Vermont from 2010-2015.

Where do people live who have acquired Anaplasmosis?

Cases of Anaplasmosis have been reported in nine out of 15 Vermont counties. Most cases have been reported in southwestern Vermont in Bennington and Rutland Counties. Also, 65 percent of cases were acquired indigenously within Vermont, 33 percent of cases had an unknown exposure, and two percent of cases were acquired out of state.

Vermont Anaplasmosis Cases by County of Residence in 2015.
Vermont Anaplasmosis Cases by County of Residence in 2015.

What are the symptoms of Anaplasmosis?

Symptoms of Anaplasmosis include:

  • Fever
  • Headache
  • Chills
  • Muscle aches
  • Fatigue

Individuals may also experience abdominal pain, nausea, vomiting, diarrhea, and rash (rare). Signs of illness typically appear five to 21 days following a tick bite and last about one to two weeks.

If you are experiencing these symptoms and have been recently bitten by a tick, it is important to speak with your doctor. In some individuals, untreated Anaplasmosis can become a life-threatening illness. In 2015, 24 percent of Anaplasmosis cases were hospitalized.

How is Anaplasmosis Diagnosed?

The diagnosis of Anaplasmosis is based on a history of tick exposure and clinical signs/symptoms. It can later be confirmed using laboratory tests. However, treatment should never be delayed while waiting for laboratory test results.

What is the treatment for Anaplasmosis?

The treatment of choice for Anaplasmosis is the antibiotic Doxycycline.

How can we prevent Anaplasmosis?

There are three easy steps we can all take to protect ourselves from tick bites and still enjoy time outdoors:

  • Avoid Ticks: When outdoors, walk in the center of trails and avoid wooded areas.
  • Repel Ticks: Use 20-30 percent DEET on skin/clothing and/or treat clothing/gear with permethrin.
  • Remove Ticks: Bathe or shower within 2 hours after spending time outside in tick prone areas, conduct a full body tick check using a mirror, inspect pets and gear for ticks.

Sources/To Learn More:



Note: Graphs and data courtesy of the Vermont Department of Health

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