Information on Ticks in Vermont

Tick Syndrome Graph
What does the graph tell me?

What does the graph tell me?

  1. Tick-related emergency room visits are most common in the spring, when blacklegged tick nymphs are abundant, and fall, when adult blacklegged ticks look for one more meal before winter arrives.  
  2. Spring tick activity is associated with increased cases of Lyme disease and anaplasmosis, and Vermonters continue to be at risk for anaplasmosis during the fall months. Be tick smart when outside these times of year.

What Should I Do?

It is time to Protect, Check, Remove and Watch. Visit our Prevent Tick Bite and Tickborne Diseases webpage to learn how to prevent and respond to tick bites.

How was this graph built?

The Health Department collaborates with hospitals across the state to collect data on recent emergency room (and some urgent care) visits. Information like the date of the visit, reason for the visit, and diagnosis are analyzed to detect public health events and monitor trends in disease activity. Interactions between ticks and humans can be monitored by searching the system for tick-related visits such as “tick in armpit” or “tick removal.”

What do all the bars and lines mean?

The graph shows the weekly percentage of visits due to tick-related issues. The blue line represents the average percent of visits due to tick-related issues at that time of year (based on information collected from 2004-2016). The orange line represents the highest percent of tick-related visits that has been recorded in that time of year. The green bars show the percent of visits due to tick-related issues in the current year. The information is analyzed on a weekly basis, and the most recent data for this year is pointed out in the green box.

Why do the bars and lines go up and down throughout the year?

Ticks are generally active when the weather is warm. Few ticks are out searching for meals in the December, January and February, so tick-related visits are low during those times. As spring approaches, ticks become more active and tick-related visits increase. In late summer (August and September) tick-related visits decrease mainly because ticks are less active while they molt from smaller nymphs into larger adult ticks. But tick-related visits increase once again when the adult ticks become active looking for one more meal before winter sets in.

Types of Ticks in Vermont

Thirteen different species of ticks have been identified in Vermont (click here for the full list). Of these 13 species, five are known to bite humans and four of those five can transmit diseases. However, over 99% of all tickborne diseases reported to the Vermont Department of Health are caused by only one tick: the blacklegged tick.

American Dog Tick
Image of a dog tick

Name: American dog tick (Dermacentor variabilis)

Distribution: American dog ticks can be found throughout Vermont.

Habitat: found mostly in grassy fields and other areas with little tree cover

Hosts: feeds on small rodents and medium-sized wild mammals, domestic cats, dogs and humans

Transmits: in Vermont the American dog tick can transmit tularemia, but human cases are extremely rare. Both adults and nymphs can transmit tularemia, although nymphs rarely bite humans.

Active: from April through September

Blacklegged Tick
Image of a blacklegged tick

Name: Blacklegged tick (Ixodes scapularis)

Distribution: Blacklegged ticks can be found throughout Vermont.

Transmits: Lyme disease, anaplasmosis, babesiosis, Powassan virus disease, and Borrelia miyamotoi disease.

Hosts: white-footed mouse, deer mouse, chipmunks, shrews, white-tailed deer.

Activity: in Vermont, blacklegged tick activity fluctuates throughout the year. After laying low during the cold winter months, these ticks usually become active in late March or early April. Their peak activity typically occurs in May and June when nymphal ticks are looking for a host. Tick activity increases once again in October and November when adult ticks are looking for another host before cold winter temperatures set in once again.

Although blacklegged tick activity typically follows this pattern, it is important to note that these ticks might be encountered at any time of year when the temperature is above freezing.

Brown Dog Tick

Name: Brown dog tick (Rhipicephalus sanguineus)

Distribution: Brown dog ticks can be found throughout Vermont.

Transmits: The brown dog tick will bite humans, but there is no evidence that it transmits diseases in Vermont.

Hosts: mostly dogs

Habitat: Generally brown dog ticks can be found wherever humans and dogs live. Unlike other tick species, the brown dog tick is well-suited for living indoors.

Active: may be active throughout the year

Lone Star Tick
Image of a lone star tick

Name: Lone star tick (Ambylomma americanum)

Distribution: The lone star tick has been found in three Vermont counties. Through Project Lone Star and other surveillance work we are searching for the lone star tick across the state so we can support Vermonters with information to protect themselves.  Project Lone Star Status Map

Habitat: woodlands with plenty of undergrowth

Hosts: feeds on squirrels, raccoons, deer, cattle, some bird species, cats, dogs and humans

Transmits: the lone star tick is responsible for transmitting ehrlichiosis and tularemia in the U.S.

Active: April through September

Squirrel Tick

Name: Squirrel tick (Ixodes marxi)

Distribution: Squirrel ticks can be found throughout Vermont

Transmits: the squirrel tick can transmit Powassan virus

Hosts: mostly squirrels, but also other medium-sized mammals

Habitat: squirrel ticks typically live in the nests of their hosts

Transmits: Powassan virus disease, although this disease is extremely rare in Vermont

Active: generally in warmer months

Woodchuck Tick

Name: Woodchuck tick (Ixodes cookei)

Distribution: Woodchuck ticks can be found throughout Vermont.

Habitat: generally found in the burrow of its host animal, rarely found on vegetation

Hosts: woodchucks, foxes, skunks, weasels, porcupines, small mammals, some bird species, raccoons, cats, dogs and humans

Transmits: Powassan virus disease, although this disease is extremely rare in Vermont

Active: generally in the summer months

Pathogen prevalence in blacklegged ticks

The Vermont Department of Health has collaborated with colleagues at the Vermont Agency of Agriculture and Lyndon State College to determine the prevalence of disease in Vermont's blacklegged tick population. Over 2,000 ticks were collected and tested between 2013 and 2016. 

PAthogen Percentage of ticks that tested positive
Anaplasma phagocytophilum 7.0%
Babesia microti 0.8%
Borrelia burgdorferi 52.9%

Over 60% of the ticks collected as part of this initiative tested positive for at least one disease. A small sample of these ticks was also tested for Powassan virus. Approximately 1% tested positive for Powassan virus.

Blacklegged ticks can carry more than one pathogen at the same time. Almost 5% of the ticks tested positive for two or more pathogens. The most commonly found combination (4.0%) found in ticks were the pathogens that cause anaplasmosis and Lyme disease.  

Use the tick tracker

Spot a tick? Share information about where and what kind of ticks you found.

Tick Tracker