Deer population, harsh winter causing surge of suckers?
By Abram Neal
Some health officials across Massachusetts are bracing for a particularly bad season for tick-borne disease this summer due to increasing deer populations and the effects of recent severe winter weather.
There are more than 95,000 deer statewide, according to the Mass. Department of Energy and Environmental Affairs. Densities range from about 10-15 deer per square mile in northwestern Massachusetts to more than 80 deer per square mile in areas of eastern Massachusetts closed to hunting.
Last winter added to the problem.
“The deep snow likely served as an insulator, much to everyone’s chagrin,” Thomas N. Mather, director of the University of Rhode Island’s Center for Vector-Borne Disease and its TickEncounter Resource Center (tickencounter.org) said in published reports last month.
Other experts see a supposition being voiced base on the biology of the tick, but urge people to take precautions just the same.
“I don’t care what people are saying about tick numbers, it’s absolutely critical that people be vigilant,” said State Public Health Veterinarian Dr. Catherine Brown. “There are infected ticks, and lots of them, every single year.”
While the state Department of Public Health (DPH) does not keep count of tick populations, reported cases of Lyme disease number at least 4,000 per year in Massachusetts, according to Brown, who added that represents “a big under-reporting.”
“We don’t actually know that there was a tick explosion because we don’t do any tick surveillance data,” Brown said Tuesday. “In Massachusetts we know that we have large populations of ticks every year and that a certain percentage of them are going to be infected with Lyme disease, Anaplasmosis or Babesiosis.”
Mosquitoes often get the most attention this time of year because of the higher incidences of arboviruses such as West Nile and Eastern Equine Encephalitis (EEE) carried by the vectors. As of Wednesday, however, there have been no positive test samples for either EEE or West Nile across the state.
“The information on the populations of mosquitoes are that most of them are running average, so there’s nothing that’s really standing out one way or the other,” Brown said. “We had a dry fall and also a dry spring.”
But with recent heavy rainfall, Brown cautioned, we are not out of the woods yet, where mosquitoes are concerned.
“Mosquitoes like moisture, obviously,” she said. “I think we’re just at the time where we’re going to start to see development of more significant mosquito population. We’re right at the beginning of mosquito season.”
Mosquitoes are also more easily managed than ticks, but tick-borne diseases are equally damaging to human health.
Deer ticks, which carry Lyme disease — as well as Rocky Mountain Spotted Fever, Babesiosis, and Human Granulocytic Anaplasmosis (HGA) — are prevalent during this time of year.
The highest incidence of Lyme is seen in June, July, and August with the most affected age groups are youngsters ages 5 to 9, and older adults between 65 and 75. Data from the Mass. DPH and the Centers from Disease Control and Prevention, shows Bristol and Plymouth Counties, along with Cape Cod and the Islands have the highest incidence rates in the State.
At dawn and dusk, ticks of all varieties sit on the end of branches or blades of grass and extend their front legs to latch onto hosts, medical entymologist Wayne Andrews told those attending a public information forum on tick and mosquito-borne diseases held at Hanson Middle School in 2013. June is the highest-risk time as both nymph and adult ticks are questing for a host at that period in their two-year life cycle.
“I don’t care where I go now, I will get a deer tick on me,” he said. “The morning is the most dangerous time … it’s nice and humid, nice and wet and they will get on you.”
Ticks thrive in brush, wooded, or grassy places and they are after blood, on which they feast after biting an animal or human — that, too, is how they spread disease.
Knowing the wildlife attractive to ticks, and how to keep them out of your yard can also help.
“Ticks are brought to your yard by deer and become infected mainly by feeding on mice,” according to tickencounter.org. “Keep deer out by planting undesirable plants, installing deer fencing or applying deer repellents.
“Mice like to live in stonewalls, around sheds, woodpiles or any enclosed area they can get into. Clean up brush, keep stonewalls clear of leaves, move woodpiles away from daily activity,” the site suggests. “Birdfeeders also attract deer and rodents that may drop ticks off right where you are standing.”
Cathleen Drinan, health agent for both Plympton and Halifax, emphasizes personal protection and education to combat tick-borne diseases. In our region, 58 cases of Lyme disease and two of HGA were discovered in Halifax alone last year.
The culprits aren’t always deer ticks, either, according to Drinan; dog ticks and wood ticks can also cause disease.
The Commonwealth, after a special report was commissioned in 2013 by the General Court, is taking both short and long-term approaches to this public health menace, hoping to return tick-bite rates back to those of 30-50 years ago in the next 25 years.
Vaccination, environmental modes of intervention, deer management, and education on personal protection, are some of the goals set forward in the report.
Ticks usually need to be attached to their host for 24-hours for Lyme disease to develop. Symptoms in humans typically include a round rash for up to a month after the bite, characterized by a clear area in the center, yet this rash does not always develop. Vague flu-like symptoms are also present in the early stages of the disease. Even if symptoms lessen without treatment, the disease may not have cleared completely, so early treatment with antibiotics is necessary to prevent more serious problems from developing months or even years later. These include serious joint, nervous system, and heart problems that can be permanent. Meningitis, an often deadly swelling of the membrane covering the brain, can even develop.
Patients with a “classic” donut-shaped rash are easy to diagnose, but otherwise most of the infected will need a blood test to confirm the Lyme Disease diagnosis.
The best ways to protect yourself from tick bites are to avoid areas where ticks live. If this is not possible, wearing long sleeves and tucking pants into socks are essential. Spraying shoes and legs with insect repellents (make sure they are effective against ticks by reading labels carefully), checking for ticks frequently, and removing ticks quickly with tweezers without squeezing or twisting are all good prevention measures, according to the DPH.
“It is very important for people to educate themselves on the seriousness of this and to use all the personal protection measures they can,” according to Drinan. For more information, visit mass.gov/eohhs. Contact a doctor or nurse if you think you are ill sooner rather than later. All local boards of health have information on ticks, tick-borne diseases, and disease prevention methods.
(Express editor Tracy F. Seelye contributed to this report.)