'Aggressive' Tick Species Is Expanding Its Reach In Massachusetts

BOSTON, MA — The lone star tick, an aggressive pest that carries several human diseases, is rapidly expanding across the Northeast, including in Massachusetts, according to scientists at Center for Vector Biology and Zoonotic Diseases and Northeast Regional Center for Excellence in Vector-borne Diseases. The tick's range previously reached no further north than southern New Jersey, but there are now established populations in Connecticut, Long Island, and Cape Cod. They have also been reported in most Massachusetts counties.

In an article in the New England Journal of Medicine, the researchers wrote that in addition to expanding the tick's range, climate change may also lengthen the pest's active season. Lone star ticks do not spread Lyme disease, but they carry a number of other human diseases. Among them is alpha-gal syndrome, a type of red meat allergy, and STARI, which is similar to Lyme disease.

"More than 90% of the nearly 60,000 cases of nationally notifiable vectorborne diseases reported in 2017 were linked to ticks. As the geographic ranges of multiple tick species continue to expand, invasive tick species are being discovered, new tickborne pathogens are emerging, and coinfections in ticks are surging," the authors wrote. "Local abundance of lone star ticks and the likelihood of getting multiple bites can be highly irritating, even in the absence of disease transmission."

Having both lone star ticks and pre-existing populations of deer ticks "complicates management strategies," they note.

Dr. Catherine Brown, the Massachusetts state epidemiologist and state public health veterinarian, warned that while the expansion of lone star ticks is a concern, the deer tick remains the primary threat in Massachusetts.

"It is important for residents to know that this new tick species is beginning to establish itself in the southeastern-most portions of the Commonwealth but it is more important that they understand that it is the black-legged (deer) tick which is responsible for almost all tick-borne disease in Massachusetts," Brown said. "Tick bite personal prevention measures remain the best protection against all tick species."

The number of lone star ticks submitted to The Connecticut Agricultural Experiment Station increased by 58 percent from the period of 1996-2006 to 2007-2017, according to a study by the same authors. According to the New England Journal of Medicine article, there are established lone star tick populations in Barnstable, Nantucket, and Dukes Counties, Massachusetts.

In their traditional range, adult lone star ticks are most active from mid-March through late June, nymps, mid-May through late July, and larvae, July through September, according to the Centers for Disease Control.

"We believe it’s essential for practitioners and the public to develop a heightened awareness of the health risks associated with emergent tick vectors such as the lone star tick and their potential for changing the dynamics of tickborne diseases in the northeastern United States and elsewhere," the authors wrote.

"Unfortunately, there are no effective, community-wide interventions available for any tick species," Brown said. "So awareness and personal prevention remain the best recommendations."

The Massachusetts Department of Public Health has tips on protecting against tick bites and tick-borne diseases. One of the most important things is checking yourself for ticks whenever you spend time in shady, damp, brushy, wooded, or grassy areas.

Christopher Huffaker can be reached at 412-265-8353 or chris.huffaker@patch.com.