URI scientist: Fewer deer ticks, less Lyme disease expected this year

KINGSTON, R.I. — May 5, 1999 — At last, some good news for Rhode Islanders from the world of biting bugs! A URI expert predicts that we won’t have as many deer ticks on our hands, our backs, or legs this spring and summer. That’s because there will be fewer of those blood-sucking arthropods around to bug us. The nympal-stage ticks, which begin to appear this month and are responsible for transmitting most disease-causing microbes, are not expected to be as abundant as last year. This information comes straight from University of Rhode Island’s tick expert Dr. Thomas Mather, head of URI’s Center for Vector-Borne Disease, whose laboratory has been conducting statewide tick and tick-borne disease surveillance for the past seven years. Fewer deer ticks mean the number of Lyme disease cases should drop as well from last year’s record number of 786 reported cases. In the past, whenever there is a lean tick year, the number of humans infected with the Lyme disease also is lower. Mather’s prediction flies in the face of widely-published reports that a bountiful crop of acorns throughout much of the northeastern United States, including Rhode Island, during the past two years created conditions fostering a skyrocketing number of infected deer ticks and, therefore, a high risk for Lyme disease this spring. “Nuts!” says Mather with a tongue firmly planted in his cheek. “We haven’t found a correlation between the number of ticks and acorns.” In contrast, the reason Mather predicts that there will be fewer ticks this year is because of the drier-than-usual weather this winter and spring. Already, for the month of April, Rhode Island has experienced more than an inch less precipitation than normal. Farmers and home gardeners have noted the dry condition of the soil. And ticks need moist soil conditions in order to survive. “Deer ticks are very sensitive to drying out and need high levels of humidity in the microenvironment where they live,” explained Mather. “Otherwise, they just dry up and die,” he added. Of course, fewer ticks doesn’t mean that you or your family shouldn’t take precautions. People living in areas with high tick populations need to be careful as do visitors to these areas, particularly hikers and campers. For personal protection against ticks, it is best to wear light-colored clothing and especially long pants tucked into socks. Spray repellent on clothing and shoes. And if you do wear shorts, be sure to spray repellent on socks and shoes before putting them on. After being outdoors, conduct a full body check for ticks, focusing particularly on areas where clothing constricts and restricts tick movement, especially around the crotch, arms, and knees. Don’t expect the new Lyme disease vaccine to protect you from other diseases carried by ticks such as human granulocytic ehrlichiosis and babesiosis. These diseases are more dangerous than Lyme disease and are on the rise. One of Mather’s recent studies revealed that out of 100 blood samples, 14 tested positive for Lyme disease and 7 tested positive for babesiosis. “The new Lyme vaccine should be used as just one arrow in a whole quiver of arrows aimed at protecting you and your family against diseases carried by ticks” stated Mather. “And if you haven’t started the 3-course vaccination program already, it’s too late to achieve vaccine protection this year,” he said. URI surveys confirm that deer ticks continue to reside most abundantly in the southern portion of the state. On the mainland, the towns of South Kingstown, Charlestown, and Narragansett have the highest tick populations, followed by North Kingstown and Exeter. Prudence Island and Block Island are other tick hot-spots, and the tick population on Jamestown is also on the rise. Anyone looking for information on how to remove ticks or find physicians expert in diagnosing Lyme disease can call a toll-free (anywhere in New England) information hotline—l-888- SCH-TICK (1-888-724-8425), inaugurated in 1997 by South County Hospital and URI. People with access to the Internet can visit the Rhode Island Public Health Partnership in Infectious Disease Control website which Mather heads. The site offers information about Lyme disease and gives town by town data on disease risk as well as other useful information. The address is www.public-health.partner.uri.edu. Tick-borne diseases are hard to diagnose. Lyme disease—symptoms include fever, headache, joint pain, often accompanied by a red rash often, but not necessarily, resembling a bullseye that increases in size over a week to 10 days. To be Lyme disease, the rash must be at least 2 inches in diameter. If untreated, Lyme disease can cause severe arthritic, nervous or heart disease. Human Granulocytic Ehrlichiosis (HGE) (pronounced air’licky’osis) symptoms include acute high fevers, severe myalgia, headache and nausea. Symptoms are accompanied by a loss of white blood cells and platelets. Cases usually require hospitalization and can be fatal. Babesiosis–(pronounced bab’easy’osis) symptoms include spiking chills, fever, lassitude and anemia. Caused by a malaria-like parasite of mice transmitted by ticks. Can be fatal, especially in older patients with weak immune systems. For More Information: Dr. Thomas Mather, 401-874-5616 Jan Sawyer, 401-874-2116