(Editor’s note: This article by Cherise Madigan was first published in the Bennington Banner on April 24, 2017.)
[B]ENNINGTON — Bennington County faces severely high levels of tick borne diseases, with the highest rates of illnesses including Lyme, anaplasmosis and babesiosis in the state of Vermont.
“In 2015 Vermont had the highest incidence of Lyme disease in the United States,” said Bradley Tompkins, an infectious disease epidemiologist at the Vermont Department of Health. “Bennington is the highest incidence county in Vermont not only for Lyme disease, but for anaplasmosis as well.” With such a high rate of infected ticks in Vermont, experts emphasize the importance of recognizing that the majority of tick bites have the potential to transmit an illness.
“There is a very high burden of infected ticks, especially in Bennington County,” said Doctor Marie J. George of the Infectious Disease Department at Southwestern Vermont Medical Center. “In fact, 63 percent of ticks are infected statewide with at least one tick borne illness, with some carrying two at the same time.”
Geography is partially to blame for Bennington’s severe incidence of tick borne illness, according to the Vermont Department of Health.
“I think part of this is that we have seen a northern trend or expansion of a lot of these tick borne illnesses,” said Tompkins. “In the ’70s or ’80s when some of these diseases were first recorded it was in the coastal areas of New England. Bennington County, being the southernmost county in the state, has seen the brunt of these tick borne diseases for the longest amount of time.”
Bennington County finds itself in a perfect storm for the transmission of tick borne illnesses with large swaths of forest, high numbers of individuals working in the outdoors during summer months, and a booming outdoor recreation industry.
“You have to have the presence of the black legged tick, you have to have the pathogen there to infect the ticks, you have to have the proper wildlife like deer and white footed mice to maintain the pathogen cycle in the community, and then you have to have people interacting with the ticks,” said Tompkins. “It’s a very complex issue, and there are a number of factors in play.”
Of the five infections associated with the black legged tick, Lyme is the most common with about half of the 2,000 ticks tested by the Vermont Department of Health infected. Bennington County reported the highest incidence of Lyme in Vermont with over 200 cases per 100,000 in population in 2015 (the most recent year for which data is available).
Though Lyme disease is a serious concern for Bennington County, the steadily rising incidence of anaplasmosis is a troubling trend for health care providers. While the rate of Lyme disease statewide was 394 per 100,000 in population in 2015, anaplasmosis is catching up with a rate of 217 cases per 100,000.
“It’s much easier to transmit anaplasmosis compared to Lyme disease,” said George. “There’s a lot to work out about why anaplasmosis is rising in incidence, and it is more severe.”
Anaplasmosis is a bacterial illness resulting in symptoms like high fever and low white blood cell counts.
“We’ve had two patients with encephalitis [brain inflammation], and we’ve had a couple of patients presenting symptoms similar to septic shock,” said George. “Patients can get much sicker, we see more hospitalized patients with anaplasmosis than we do with Lyme disease because of the severity of illness.”
Statistics show that the rate of anaplasmosis is steadily rising in Vermont, with significant growth in Bennington County specifically. In 2014 there were 69 reported cases of anaplasmosis in Vermont, with 43 percent of cases in Bennington County. In 2015 the number of reported cases rose to 139 statewide, 63 percent of which were in Bennington County. The Vermont Department of Health estimates that approximately 7 percent of all ticks in the state are currently infected with anaplasmosis.
Also rising in incidence is babesiosis, which has become more prevalent in neighboring states including Massachusetts and Connecticut. Because rates of tick borne illness tend to rise from south to north, experts worry that babesiosis may soon become more severe in Bennington County as well.
“More southern states are seeing their numbers increase over the past few years, so we are concerned that Bennington and Windham county may see an increase in the coming years as well,” said Tompkins. “Babesiosis is particularly nasty, and it hospitalizes just about half of the Vermonters that get it. In comparison, about 3 percent of the people that get Lyme are hospitalized, and about a third for anaplasmosis.”
Babesiosis is caused by a parasite which targets the red blood cells, and requires a different treatment than Lyme or anaplasmosis, which can often be treated in conjunction.
Another illness, borrelia miyamotoi, is slowly emerging as well but is particularly difficult to diagnose due to the similarity of symptoms with Lyme and anaplasmosis.
The fifth disease carried by black legged ticks, powassan virus, can cause severe brain inflammation and hospitalization though it has not been recorded in Vermont in recent years.
Tick borne illness can be difficult to diagnose and record as many diseases present similar symptoms, and illnesses can occur (and often be treated) simultaneously. To target this issue, Southwestern Vermont Medical Center is working to maintain the most accurate data on reported cases in the state.
“The laboratory that we use to detect tick borne illness allows us to do a panel where we can find all of them at once, so even though there’s so many crossover symptoms we can truly tell what we have,” said George. “For example, we’re the only ones in the state that are looking for borrelia miyamotoi, and we are finding it.”
The greatest challenge for SVMC so far has been educating the public on the risks associated with tick bites.
“The fact that these diseases don’t often kill a person make it harder to raise awareness,” said George. “We want the information to get out. It’s hard for us to watch people be afraid of going outdoors, and understanding prevention is so important. Pretty soon it’s going to be exploding here.”
Information of how to prevent tick bites and tick borne diseases can be found online through the Vermont Department of Health.
