In 1969 an elderly woman on Nantucket came down with a fever that required hospitalization and she returned home to the mainland. The laboratory technician who examined her blood had served in Vietnam and noticed organisms that looked very much like malaria.
Not unique
Although Islanders like to think of Martha's Vineyard as a unique part of the world, when it comes to deer ticks we have much in common with the rest of the world
"We are not unique with respect to deer ticks and Lyme disease," Mr. Telford said. He demonstrated the distribution of deer ticks (Ixodes persulcatus) with a map of the world that showed a band across the northern latitudes that includes portions of Europe and Asia.
The two- to three-year life cycle of the deer tick can be divided into four stages: the egg hatches and becomes a larvae; the larvae grows into a nymph; the nymph becomes an adult and lays eggs. The tick requires a blood meal to reach each stage in its development and reproduce or it will die.
"Nymphs are around right now," Mr. Telford said. "They actually came from larvae that were around last year feeding in August and September."
The source of the blood meal could have been a mouse or a bird that spent a lot of time on the ground. Nymphs are typically around in June, but this year Mr. Telford said that schedule was pushed back to July due to the cold wet weather.
Mr. Telford would not be surprised to see an increase in Lyme cases precisely because the peak of the nymphal season was delayed to a time when more people visit the Island.
Speaking in mid-July he said, "Nymphs, they are around right now, they are looking for things to feed on; they will feed on people, they will feed on dogs; they will feed on birds, they will feed on mice, they will feed on deer and if they get a blood meal they will develop into adults by the fall."
By contrast, he said, adult deer ticks only feed on large animals such as deer, dogs, horses, and people. An adult deer tick that has fed successfully will lay 2,000 eggs. Those eggs sit around during the winter and hatch the next summer.
Why isn't the Vineyard awash in deer ticks? No one really knows, Mr. Telford said.
The chief culprit in transmitting infection is the nymph, according to Mr. Telford. That is because few adult deer ticks go undiscovered long enough, approximately 24 to 48 hours, to transmit infection.
Pointing to a photo of a deer tick in the nymphal stage, about the size of the period on this page, Mr. Telford said, "This is really what you should be looking for right now. In fact, you don't really look for them, you kind of feel for new pieces of stuff on your skin," he said.
A tick check remains the most important means of prevention, Mr. Telford said. That should be combined with appropriate clothing - pant legs tucked into socks - an insect repellant that contains DEET, and awareness of tick habitat.
Evolving danger
Although it is the deer tick that has come to dominate discussions about tick-borne diseases on Martha's Vineyard, more than 100 hundred years ago the Island was famous for the prevalence of dog, or wood ticks. Deer ticks were virtually unheard of, Mr. Telford said.
Several factors have dramatically altered the natural equation. Much of the Vineyard landscape of heavy dense brush that exists today under multiple layers of regulatory protection was once open pastureland.
Deer ticks require moisture to survive. Dense brush that holds moisture provides good deer tick habitat. In the past, the open pastureland did not provide good deer tick habitat.
Another critical factor is the growing deer population. Deer provide the blood meal adult deer ticks need to reproduce.
"I'm the poster boy for deer reduction," Mr. Telford said. He noted that he has received no money to study Lyme disease for ten years and often must rely on the generosity of others to find a place for him and his graduate assistants to stay when they visit the Vineyard to conduct fieldwork.
Mr. Telford said the deer tick is here to stay. The question is how many. There is no magic bullet, he said. He said money is important, but without commitment it will mean nothing.
Mr. Telford said that a concerted approach that combined spraying, habitat management, and deer management could reduce deer ticks on Martha's Vineyard.
Mr. Telford said that current rigid notions of conservation make it difficult to change the culture that allows ticks to thrive. "It certainly is a problem for trying to change the culture, trying to get people committed to doing something," he said. "This idea that what you see around you is natural. It isn't. You just have to look at old photos from the forties and thirties. Unfortunately a lot of conservationists are too rigid."
Mr. Telford quoted Dr. Joe Piesman of the Centers for Disease Controls and Prevention, who spoke about Lyme at a national conference. "We know how to kill ticks. We just don't know how to get people to do it."
Mr. Telford's presentation "Tick me off" will be broadcast on MVTV tonight at 7 pm and Friday at 4 pm.
