Editorial : Trim and thin
Too many deer and too much underbrush lead to the unhappy fact that there are too many disease-carrying ticks sharing our Island paradise with us.
Sam Telford, associate professor of infectious diseases at the Tufts University School of Veterinary Medicine and a highly regarded 25-year veteran tick researcher, talked ticks at a forum sponsored by the Martha's Vineyard Hospital on July 16. He described the links between ticks, tick-borne diseases, and the Vineyard's natural habitat, and he said that the Vineyard might move successfully to reduce the growing deer tick population and, in doing so, protect current and future human residents and guests, but only if it determines to do so.
Times managing editor Nelson Sigelman, reporting in the July 30 Times on Mr. Telford's talk, explains that although the deer tick is now the key to tick-borne diseases on the Vineyard, more than 100 hundred years ago the dog, or wood, tick dominated. There were few deer ticks, the expert said. Now, a landscape of dense brush, protected by layers of environmental regulation, has replaced open pastureland. The low, choking growth nurtures the moisture that deer ticks need to survive and improves survivability for the growing deer population. Deer feed adult ticks the blood meal they need to reproduce.
Mr. Telford is a tick guy, fascinated by the creatures and their natural history. He is also deeply conversant with the danger they pose to humans. The smaller deer tick, the focus of Mr. Telford's slide presentation, infects humans with Lyme disease, the best known of tick-borne illnesses. Then there's malaria-like babesiosis, also known as Nantucket fever, and ehrlichiosis (HGE), a disease related to Rocky Mountain spotted fever. This spring, medical researchers confirmed that the deer tick is also capable of causing deer tick viral encephalitis (inflammation of the brain) in humans. The larger dog, or wood, tick carries Rocky Mountain spotted fever, a disease that was once more prevalent across New England and has now pretty much disappeared, although researchers do not know why, Mr. Telford said. It also carries tularemia, a disease that continues to pose another medical mystery, due to several outbreaks clustered on the Vineyard.
"I'm the poster boy for deer reduction," Mr. Telford told the 40 or so who attended the hospital's talk. The deer tick is here to stay, but its numbers might be reduced by reducing the size of the deer herd. Combined with pruning the deer herd, spraying for pest control, and habitat management could significantly reduce the deer tick population and thus the threat that population poses for our own.
But it's not easy. "It certainly is a problem 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 added an observation by 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."
If there is a serious question worth serious research and scientific study, as opposed to what is generally a lot of planning blather, it is an investigation of ways to thoughtfully control the Vineyard's extravagant and smothering vegetative habitat and its consequently multiplying resident deer population. In the interests of the future good health of Islanders and their visitors, here's something positive the Martha's Vineyard Commission might profitably undertake on our behalf.