TRENTON, N.J. (AP) - Call them the pest posse. Mice are being used to kill a more dreaded pest - ticks - in the latest strategy for preventing Lyme disease.

A new contraption developed by federal scientists and a subsidiary of pharmaceutical giant Aventis lures the rodents that harbor bacteria causing Lyme disease into bait boxes. As mice pass through the child- and pet-proof boxes, an oily wick coats their shoulders with the same potent tick-killing compound used to protect dogs and cats.

The Maxforce Tick Management System is touted by maker Aventis Environmental Science of Montvale as able to kill nearly all ticks around a home within a year or two. It breaks the cycle of young ticks, often smaller than a freckle, being infected by rodents and then infecting other animals or people, the company says.

The bait boxes are spaced along the edge of yards, where ticks and the mice and chipmunks on which they feed lurk among brush and trees - and where roughly 75 percent of people who get Lyme disease are infected. They must be installed and replaced periodically by trained exterminators, at a cost of $300 to $600 a year.

``It's absolutely brilliant,'' says Leslie Cummin, a landscape architect living on a once tick-infested Connecticut island where Aventis and the Centers for Disease Control and Prevention tested the product. ``After four years, we don't have any ticks.''

Cummin's waterfront home and the rest of Masons Island off Mystic, Conn., had so many ticks that Lyme disease was common among the 400 residents. Nightly ``tick checks'' were a ritual.

Within a few years of moving there a decade ago, Cummin, her husband and one son all got the disease, which begins with flulike symptoms and often a bull's eye rash. They were cured with antibiotics, but untreated Lyme disease can cause long-term joint inflammation and nerve damage.

Cummin said ticks brought into their house on boots and their dogs - who sometimes had 50 ticks each - once clung to the walls, waiting to jump on their next meal.

``In the middle of the night, you'd wake up and feel something tickling, and there'd be a tick walking up your leg,'' she recalled.

In 1999, scientists from CDC's Division of Vector-Borne Infectious Diseases began field testing bait boxes with wicks coated with fipronil, an insecticide patented by Aventis. The chemical proved far more effective at killing ticks and preventing disease transmission than others tested in the laboratory, said Gary Maupin, an Aventis consultant who then was a CDC senior health services officer.

A 10-acre test plot where 125 bait boxes were spread the first year had 80 percent less ticks than an untreated area; after the second year, there were 96 percent less ticks in the treated area. The study now includes nearly the whole island.

``This will be potentially a very useful tool for preventing Lyme disease,'' said Dr. Ned Hayes of the CDC's Lyme disease program, which now is studying whether the bait boxes reduce Lyme disease infections in people.

Cases of Lyme disease, named for the Connecticut town where it was discovered in 1977, have been rising in the northeastern states where it is most common. In 2000, nearly 18,000 U.S. cases were reported, but health officials believe 90 percent of cases aren't diagnosed.

Dr. Leonard Sigal, director of the Lyme Disease Center at Robert Wood Johnson Medical School in New Brunswick and medical director at the American Lyme Disease Foundation, said the system makes sense.

``You're targeting the problem and you're not spraying chemicals all over the galaxy,'' he said.

Sigal said the system needs to be tested in other neighborhoods and other climates. He recommends people also use other strategies, such as clearing brush around their property, using insect repellent and showering after being outdoors.

　　From Healthy.net