As the deer population increases, concerns over the prevalence of Lyme disease have been growing at the Binghamton University Nature Preserve and throughout the surrounding area.
Led by research professor of biomedical anthropology Ralph Garruto, over 50 student researchers have been studying the prevalence of ticks and the increase in Lyme disease infectivity rates at BU since 2011.
The New York State Department of Health reports that the total number of Lyme disease incidents from 2011 to 2013 in Broome County is the largest amount of cases in any surrounding county in the Southern Tier.
According to Mari Yourdon, a public health nurse in the Communicable Disease Program at the Broome County Health Department, incidents of Lyme disease in Broome County have continuously increased in the last 20 years. In 1994, there were three cases of the disease, which have swelled to 207 reported cases in 2013 and 152 cases in 2014.
At Decker Health Services, seven people have been diagnosed on-campus since 2013, but Dr. Michael Leonard, medical director of Health Services, said that many students receive services from off-campus offices as well as from their providers at home.
Adrianna Maliga, a researcher on the Lyme disease project and a senior double-majoring in biochemistry and Spanish, said that Lyme disease symptoms are similar to those of the flu, such as fever, fatigue, cold and joint soreness. Not everyone exhibits a bull’s-eye rash around the tick bite, so many people don’t report incidents when the bite is still recent and antibiotics become effective.
Maliga said that contrary to the idea that deer solely carry the infectious tick, white-footed mice are actually the best carrier for the bacteria. The mice retain the Lyme disease bacteria, Borrelia burgdorferi, the most out of every species the team has done research on. Deer are what spread the disease; however, they act as hosts to the adult ticks, carrying them across forests.
The reason for the high mouse population can be affected by a number of variables, Maliga said, including an increase in forest fragmentation, which in turn is affected by the high deer population. For healthy forests, she said, there should be about five deer per square kilometer. In the BU Nature Preserve, there are over 40 deer per square kilometer, leading to an increase in forest fragmentation.
“There has been research done that forest fragmentation has an effect on mouse population, because the smaller the forest fragment, the smaller the ecosystem,” Maliga said. “So, that ecosystem can only support smaller animals, like mice, and their natural predators can’t live there. More mice leads to more ticks, which leads to higher infectivity rates.”
According to Amanda Roome, a fourth-year graduate student studying biological anthropology, roughly 44 percent of ticks at BU carry the Lyme pathogen, compared to 39 percent of infected ticks within the surrounding areas in Broome County.
Julian Shepherd, an associate professor of biology at BU, said the number of infected ticks across the state, and in Broome County particularly, is especially high compared to other states. Reducing the amount of deer in the Nature Preserve, he said, might curb infectivity temporarily, but not entirely.
“[The deer] certainly are important, but it’s the mice,” Shepherd said. “We’re not going to do a cull of the mice, so a deer cull would help [decrease] the spread of Lyme disease, but it certainly wouldn’t eliminate it. The ticks can feed on all sorts of other animals, like raccoons or possums.”
Maliga said that due to the trickiness of diagnosing Lyme disease, many doctors were hesitant to diagnose patients. However, after New York State Governor Andrew Cuomo passed legislation in 2014 protecting doctors from investigation after diagnosing Lyme and other tick-borne diseases, rates of the disease have increased.
“When you do testing for Lyme disease, there’s a very specific period of time that the bacteria is going to show up in the blood,” Maliga said. “If you pass that time, you can’t detect it. So we’re looking for ways to better determine when to diagnose Lyme disease.”
Lyme disease is most prevalent in the summers, because that’s the time of year that ticks are small enough and feed on the infected mice, but precautions should always be taken. According to Maliga, their research has shown that the areas with the most infected ticks are College-in-the-Woods and Hillside Community, as human traffic is close to the forest.