After her husband got Lyme disease (search), her young son kept getting tick bites in their yard and a close friend nearly died of the tick-borne infection, Laurie Gaulke felt she had to do something.

With heavy brush and a forest with deer behind her home in Gillette, N.J., Gaulke tried a new strategy three years ago: installing a tick-killing system (search) in the brush fringing her yard.

Bait inside the plastic boxes lures rodents that harbor the bacteria causing Lyme disease. A wick coats their fur with a chemical that kills ticks for up to six weeks. New boxes must be installed by trained pest control contractors each spring and summer.

Developed by the Centers for Disease Control and Prevention, the Maxforce Tick Management System (search) is one of a few new alternatives to widespread chemical spraying to kill ticks and prevent Lyme disease, which can cause long-term health problems and cost thousands of dollars to cure.

Another new device that targets tick hosts is called the 4-Poster Deer Treatment Bait Station (search), a tick-killing chemical that must be replenished weekly along with a type of corn deer like but eat only in small amounts. It was invented by the U.S. Department of Agriculture.

Experts on Lyme disease and tick control say consumers should seek data on the effectiveness of both systems before making a purchase.

Gaulke, whose family is often outside, said Maxforce began sharply reducing tick numbers after a year.

"It's not like I'm spraying something toxic ... that I have to worry about my child or my dog playing in," she said.

Maxforce and 4-Poster, two methods that directly target animals on which ticks feed, can take a couple years to reach peak effectiveness, so insecticide should be applied a few times in areas harboring ticks, pesticide contractors say.

However, a government survey found 75 percent of the public won't use a spray, said CDC senior research biologist Marc Dolan. Tick populations are extremely high in the Northeast this year, and moving west, he noted.

A quarter century after Lyme disease was named for the Connecticut town where it was first observed, it has spread to all but nine states with the exploding U.S. population of deer, the primary hosts on which black-legged deer ticks feed.

Mice, chipmunks and occasionally other rodents — but not deer — harbor the bacteria causing Lyme disease, and infect ticks that later bite people and pets.

According to the CDC, 21,273 cases of Lyme disease were reported in 2003, mostly in New England and mid-Atlantic states. CDC estimates only 10 percent of cases are reported because Lyme disease often causes only mild, flu-like symptoms.

Symptoms can also include fever, fatigue, joint and muscle aches, headache and, in some people, a bull's eye rash. Untreated, it can cause neurological problems, personality changes, sleep disturbances, disabling joint pain and swelling, meningitis or heart problems.

Dolan, who helped develop Maxforce and tested it on tick-infested Mason's Island off Connecticut, said it has cut the number of ticks by 80 percent to 95 percent after two years.

Montvale-based Bayer Environmental Science launched Maxforce under a CDC license last year and now sells it in 18 states and Washington, D.C. Prices run from a few hundred dollars to $1,000 per year, depending on property size and amount of brush.

The 4-Poster device was licensed to the American Lyme Disease Foundation, which gets a small royalty on sales, and to manufacturer C.R. Daniels Inc. of Ellicott City, Md.

J. Allen Miller, a supervisory research engineer with USDA's Agricultural Research Service, said a study in five Northeast states found 4-Poster killed 70 percent to 90 percent of ticks in two years.

"It's not spread over the environment," Miller said, and spraying uses about 1,500 times as much insecticide as the 4-Poster system.

The feeder costs $425, plus $175 for a year's worth of the tick-killing chemical.

Durland Fish, science adviser to the foundation, said it endorses the 4-poster system, though it needs improvements. One drawback is that it cannot be used near homes because children could touch the exposed chemical.

The foundation also backs Maxforce and two other products. Those are the Buzz Off shirt sold by Orvis, which claims an embedded, natural insect repellent drives off ticks, mosquitoes and other insects through 25 washings, and the Snap 3Dx Test (search), which lets veterinarians quickly test dogs for Lyme and other tick-borne diseases — a sign family members may be infected.

Fish says other strategies are in development, including a fungi spray safer than other pesticides, a Lyme disease vaccine for mice and use of nematodes, tiny worms that eat ticks.

Immunologist Dr. Steven Schutzer of University of Medicine and Dentistry of New Jersey in Newark, who has done research on tick habitats, said infected patients seem to be seeking help sooner, when antibiotics are most effective. He said few patients follow the "long sleeves, long pants tucked in" strategy to avoid tick bites, so people should avoid areas with ankle-deep brush where ticks and mice are likely to be.