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The number of Lyme cases in the United States has reached record levels, according to the latest figures from the U.S. Centers for Disease Control and Prevention in Atlanta. The agency reported 17,730 cases in 2000, an 8 percent increase from the year before. The CDC says Lyme cases are underreported.

Experts predict an especially bad tick season this year.

New strategy targets deer ticks to quash Lyme
Monday, May 13, 2002

BY CAROL ANN CAMPBELL
STAR-LEDGER STAFF

In the dense Monmouth County woods, where Lyme disease is endemic, feeding deer seems akin to feeding the rats and mosquitoes.

Yet scientists working among the county's scrubby pine and oak are using corn to lure deer to an odd metal contraption -- called a four-poster -- which could be the future of tick control. As deer dip in for a nibble, they brush their heads and necks against paint rollers laced with a tick-killing agent.

This kind of research signals a major shift in thinking about Lyme disease and other tick-borne illnesses. The aim, no longer, is to protect people only with sprays, vaccines and antibiotics. Researchers say ticks must now also be controlled in the environment, much the way public health officials control mosquitoes to reduce the incidence of West Nile disease.

"We've finally realized the answer is not in treating us, or vaccinating us. It's getting rid of the ticks," said Jill Auerbach, a Dutchess County, N.Y., resident who has emerged as a leading voice pushing for tick control in the Northeast. "We have been tackling this from the wrong end of the problem."

Deer play a crucial role in the tick's life cycle. About 98 percent of all ticks that successfully lay eggs feed on deer.

"One tick can produce up to 3,000 eggs," said Mat Pound, research entomologist for the U.S. Department of Agriculture. The eggs on the deer hatch into larvae. The larvae then feed on mice and other small rodents. It is on the mice that the ticks actually contract diseases. These larvae, now infected, can drop off the mice and grow into nymphs. The nymphs -- as small as a pin head or poppy seed -- can then attach to shrubs and trees. When deer or humans pass by, the nymphs are attracted by the warmth of the body and climb aboard.

"But if we kill the adult female before she lays eggs (on the deer), then you don't have larvae, nymphs or a next generation," Pound said.

The tick-control movement becomes more urgent, experts say, as scientists discover new tick-borne illnesses. Moreover, the only vaccine against a tick-borne illness, Lymerix, was pulled from the market by its manufacturer, GlaxoSmithKline, in February after poor sales and reports of serious side effects. The vaccine protected against Lyme, but not against other tick-borne illnesses such as babesiosis and ehrlichiosis -- diseases that can cause such symptoms such as fever, chills, fatigue, joint pains and neurological problems. Erlichiosis kills 2 percent to 3 percent of its victims, according to the U.S. Centers for Disease Control and Prevention.

"The fact that a vaccine was tried and withdrawn only adds more emphasis to our efforts," said Joseph Piesman, chief of the CDC's Lyme Disease Vector Section. The CDC is funding research into natural methods of tick control. Piesman acknowledges funding for tick control is low -- just $600,000 this year.

"With more money we probably could do more," he said.

Some entomologists say public health experts began waging the wrong battle early on. Entomologists clamored for money to research ticks in the early days of Lyme disease, some 25 years ago.

They got little response.

"The government was quick to throw money at vaccines and treatments and antibiotics. That's what they think of first," said Durland Fish, an entomologist and tick expert at Yale University Medical School in New Haven, Conn.

He wanted the government to fight Lyme Disease the same way public health officials once battled malaria and yellow fever: kill the vector, or carrier, of the disease. He said the government is only now investing in tick research.

"We are years behind, but we don't have any choice now. There is nothing else to do. They pulled the only vaccine off the market," Fish said. "We wasted $200 million on the vaccine," he said.

The four-poster control is getting a lot of attention. It is being tested at sites from Rhode Island to Maryland.

In 1997, researchers from the USDA put 25 four-posters in a section of the 11,000 acres surrounding the U.S. Naval Weapons Station at Earle, in Monmouth County. They left the rest of the property alone. After several years, the deer in the treated area carried about one to two ticks. Deer in an untreated part of the station were found to each carry about 35 to 50 ticks.

"That tells me we are killing the ticks on deer," said Terry Schulze, a former state health official who is conducting the tests for the USDA. A white cloth dragged through the woods in the untreated section picked up about 15 to 20 ticks. Drags in the treated area picked up one to two ticks.

"Now, when I walk in the treated area, I almost never find a tick on me," Schulze said.

The four-posters cost about $240 each. One device could cover the deer in 40 acres. Fish said it will not be available to homeowners or public health departments for several more years. David Weld, executive director of the American Lyme Disease Foundation, said a subsidiary of the association will eventually distribute the four-posters.

Research is moving forward in several other areas:

  • Fungi: The CDC is funding research into two common types of fungi that kill ticks. The fungi, already used in greenhouses and on crops, can be sprayed on the edges of parks or lawns, creating a barrier to keep ticks out. Sandra Allan, an entomologist who researched the fungi at the University of Florida, said the downside is that fungi may kill other crawling creatures, such as beetles.

  • Pheromones: Researchers are exploring these chemicals, which can attract ticks toward a pesticide that would kill them. Pheromones could be used around the perimeter of a yard.

  • Bait boxes: Cotton wicks inside a small box, about six inches long, are laced with Fipronil, the same chemical used for tick control on cats and dogs. Mice and other rodents enter the box to nibble on a food block. Along the way, the pesticide lines their coat and kills ticks for up to 42 days. The CDC holds the patent along with Aventis. Joe Conti, an Aventis spokesman, said the bait boxes broke the cycle of Lyme disease when tested on a Connecticut island. Conti said the devices should be available to consumers, probably through pest control companies, before the end of the year.

    Lyme disease activists in New Jersey say the state is moving too slowly to control ticks.

    "Very little has happened. Parks that are Lyme infested are not even being posted so people can take precautions," said Pat Smith, president of the Lyme Disease Association in Ocean County.

    Two years ago, an amendment to a state law allowed county mosquito control commissions to get involved in tick control. Just a handful are doing so. They include Monmouth, Atlantic, Hunterdon and Camden counties.

    "We are trying to build up a tick-born disease program. We feel it's very important," said Sean Healy, an entomologist for the Monmouth County mosquito control commission.

    In Dutchess County, N.Y., a group of residents, including Jill Auerbach, got together and demanded their elected officials work to keep them safe from ticks. The founded an organization and Web site called STOP or stop ticks on people.

    "One of our members took her 3-year-old granddaughter to the park and then picked 23 ticks of her at night," Auerbach said. "That just shouldn't happen to anybody."

    Carol Ann Campbell covers medicine. She may be reached at ccampbell@starledger.com or (973)392-4148.