Lyme disease problem grows in Sussex County

The incidence of Lyme disease in Union County has grown a disconcerting six-fold in five years. Only two other New Jersey counties -- Sussex and Passaic -- have seen higher rates of increase.

Experts attribute the statewide increase to changes in how the disease is reported and the local increase in the region's growing deer population, among other factors. They also point to the disease's spread throughout the Northeast and into the Midwest and Southeast.

"It's very clear that it's a growing trend," said Dr. Raj Kapila, an associate professor of infectious diseases at the University of Medicine and Dentistry of New Jersey.

Many New Jersey counties, particularly rural areas like Hunterdon, Sussex and Warren counties -- with 326, 219 and 135 cases reported in 2004, respectively -- have many more Lyme disease cases than densely developed Union County. But the disease's incidence -- the number of cases per 100,000 people -- is rising in Union County more rapidly than in other counties, according to the state health department.

In 2004, about 12 people out of every 100,000 in Union County contracted Lyme disease, compared to two in 1999, an increase of 5.5 percent. In Sussex and Passaic counties, the disease's incidences -- the number of cases per 100,000 people -- rose almost 7 and 15 percent, respectively, in the same period.

Essex and Monmouth counties also saw increases in that period, with incidence rising about 3 percent in both counties. The incidence of Lyme disease in other counties did not rise significantly over the same period.

The incidence of Lyme disease has increased statewide due partly to efforts to increased reporting of the disease, said state health department spokesperson Nathan Rudy.

In 2000, the standards for reporting a case of Lyme disease changed, allowing doctors to report cases of Lyme disease that were confirmed by a laboratory but not accompanied by the characteristic bull's eye rash, said Rick Proctor, who serves as health officer for Hillside, Rahway, Scotch Plains and Winfield and as a county freeholder.

In 2004, labs testing for Lyme disease were also given access to the computer system that tracks communicable diseases, increasing the number of cases that were reported, Proctor said.

Though these procedural changes account for the statewide increase, they do not fully account for the disease's rise within Union County.

Though Lyme disease's toll varies from year to year as part of its natural cycle, experts also point to Union County's burgeoning deer population as one possible reason for the increase.

Ticks carrying the bacteria feed on deer, which serve as "amplifiers" of the disease, spreading the ticks through a larger area, said Marc Dolan, senior research biologist for the Centers for Disease Control and Prevention's division of vector-born infectious diseases.

Reducing the deer population through measures such as the hunt begun last weekend in the Ashbrook Reservation can help reduce the number of people who get Lyme disease, but will not eliminate or drastically reduce the disease, Dolan said.

"Getting rid of the deer or getting rid of the rodent populations is not a viable way to rid the U.S. of Lyme disease," Dolan said. "We can't deplete a species. We've got to find another way to combat it."

Personal protective measures like tucking one's pants into one's socks and checking one's body for ticks after outdoor activities, particularly at the height of tick season from May through July, are the first line of defense against Lyme disease, said Dolan. In a back yard, applying pesticides and landscaping to make it less tick- and deer-friendly can reduce the chance of Lyme disease.

Scientists have developed various types of "bait boxes" to apply tick-killing chemicals to rodents and deer without harming the animals, an approach that has proved "very effective" but expensive, with a rodent bait box costing $400 to $500, Dolan said.

A combination of strategies is the best way to reduce the spread and impact of Lyme disease, Dolan said. "There's no silver bullet out there for getting rid of ticks or getting rid of Lyme disease," he said.