Ticks, Lyme disease creeping northward

A female deer tick is shown under a microscope.
Victoria Arocho | AP
A female deer tick is shown under a microscope.
By Meg Haskell, BDN Staff
Posted June 15, 2011, at 6:13 p.m.

The recent cycle of chilly, rainy weather may be discouraging for sun-starved Mainers, but deer ticks, those minute carriers of the organism that causes Lyme disease, are liking it just fine.

“When the ground is dry, they just kind of hunker down under the leaves and they don’t come out until it rains again,” said Chuck Lubelczyk, a field biologist with the vector-borne disease lab at the Maine Medical Center Research Institute in South Portland.

Scientists searching for deer ticks to study often strike out when conditions are dry.

“But if we go looking after a heavy rain, they’ll be out like gangbusters,” he said.

Scientists aside, cool, damp weather for deer ticks is not high on most people’s summer wish list. It’s not just because all ticks are creepy little arachnids that bite a hole in the flesh of their host, inject an anticoagulant to keep the blood flowing, and then latch on until they are bloated and engorged.

That’s bad enough.

But Lyme disease, transmitted only by the very tiny deer tick and not by its slightly larger relative the dog tick, is a potentially serious condition that can cause an acute, flu-like sickness as well as long-lasting damage to nerves and joints. Once largely confined to Maine’s most southerly areas, Lyme disease is becoming more common in Maine’s northern counties, western highlands and down east. The carrier ticks that cause it also are being found farther afield, including in Aroostook County.

Recognized early and treated aggressively, Lyme disease can almost literally be stopped before it starts, according to state epidemiologist Dr. Stephen Sears of the Maine Center for Disease Control and Prevention. But diagnosed late in its progression, Lyme disease can cause long-term damage that resists the curative efforts of mainstream medicine.

Because people are becoming more aware of Lyme disease, Sears said Tuesday, doctors are more likely to spot the characteristic bull’s-eye rash that typically results from the bite of an infected deer tick. Starting patients on oral antibiotics right away is good medicine that usually kills the disease-causing microbe before more generalized symptoms — including fever, headache and achy joints — set in, he said.

But left too long without treatment, Lyme disease can cause ongoing inflammation, pain and fatigue that lasts long after the organism is gone, Sears said. That’s why it is important for people to be smart about deer ticks and able to recognize the bull’s-eye rash and other early symptoms that may show up even before blood tests positive.

Avoiding ticks

Even more effective than early diagnosis and prompt treatment, Sears said, is avoiding exposure to ticks in the first place.

“There are a number of very good tick-prevention strategies,” he said. Mainers should start by respecting Lyme disease as the potentially serious condition it is and understanding that it is spread by deer ticks, he said. They should know the difference between a deer tick and the larger dog tick.

Venturing into woods and fields in spring, summer and fall, people should protect themselves from ticks by wearing long-sleeved shirts and long pants tucked into socks.  Wearing a DEET-containing repellent or spraying a pyrethrum-based repellent on clothing will help keep ticks from biting or even hitching a ride. Light-colored clothing makes ticks more visible.

Homeowners should keep their grass cut short and leafy or brushy material cleared away. And people who have spent a day outside should do a “tick check” before bed, looking closely in the folds of knees and elbows, along hairlines and in other spots that tend to stay dark and damp. Having a buddy system will ensure thoroughness.

“There are places on our bodies we can’t see ourselves,” Sears observed.

Ticks typically do not bite for several hours after finding a likely host, and it takes 12 to 36 hours to transmit the Lyme disease microbe. Ticks that are not attached can simply be picked off with fingers or tweezers. Those that are already attached should be gripped with tweezers and pulled straight out. The bite area should be washed with warm soapy water followed by a dab of rubbing alcohol or antibiotic ointment.

Lyme disease in Maine

Lyme disease was first identified in Connecticut in 1975. The first case in Maine was diagnosed in 1986. The incidence of Lyme Disease in Maine has risen steadily from about 175 reported cases in 2003 to nearly 1,000 in 2009.

Lyme disease is most prevalent in Cumberland and York counties but it is becoming more common in more northerly counties.

So far this year, 79 cases have been reported. Most cases are diagnosed in late summer or fall.  Last year, the number of cases dropped to 734. Epidemiologist Sears says last year’s lower rate probably reflects a number of variables, including the hot, dry summer of 2010 and the growing awareness of Lyme disease among doctors and the general public.

There are 14 varieties of ticks found in Maine. The most common are deer ticks, dog ticks and woodchuck ticks. Only the deer tick, ixodes scapularis, carries the Lyme disease microorganism.

Scientists at Maine Medical Center have studied Lyme disease and other tick-borne illnesses since 1989. In addition to collecting ticks for their own studies, the Maine Medical Center Research Institute provides free identification of any tick. So far, about 27,000 ticks have been sent in for identification by doctors, veterinarians and members of the general public. For information and instructions for submitting a tick for identification, visit the MMCRI vector-borne disease lab website at www.mmcri.org.

 

 

http://bangordailynews.com/2011/06/15/health/ticks-lyme-disease-creeping-northward/ printed on September 19, 2014