Virginia sees rise in Lyme disease

State health officials said many counties in the state are reporting more cases of the tick-borne disease.

By Sarah Bruyn Jones

981-3264

Lyme disease in Virginia is spreading west and south after having mostly been concentrated in the northern part of the state.

"This is a very important and emerging infection in Virginia," said Dr. Keri Hall, director of epidemiology at the Virginia Department of Health, during a news conference Thursday.

Montgomery, Floyd, Pulaski and Franklin counties have all seen an increase in Lyme disease cases reported to the state. While physicians and laboratories are required to report confirmed cases of Lyme disease, Hall cautioned that it is highly likely that the state doesn't know about all instances of the tick-borne disease.

In Montgomery County, the number of reported cases jumped 500 percent from four in 2007 to 24 in 2008. Last year 17 cases were reported.

"Lyme disease is considered, and has been, endemic in many areas of the New River Valley," said Dr. Jody Hershey, health director of the New River Health District, which includes Montgomery.

State health officials said they are trying to increase the public awareness and education of Lyme disease by focusing on teaching Virginians to check themselves for ticks during the spring and summer months.

In addition to raising the general public's awareness, Virginia Health Commissioner Dr. Karen Remley sent a letter to all licensed health professionals in the state last month alerting them to the trend in Lyme disease and urging them to be vigilant in detecting the symptoms of tick-borne diseases.

Delays in diagnosing Lyme disease can lead to worse symptoms and reduce the chances of curing the disease.

The increased prevalence of Lyme disease has not been seen in Roanoke, where typically only a few isolated cases are reported. Carilion Clinic, the region's largest health care provider, hasn't seen an increase in the disease, according to its spokesman.

David Gaines, entomologist for the Virginia Department of Health, said it's a bit of a mystery as to why the Roanoke Valley has not seen the same changes in Lyme disease that the New River Valley has seen.

"It may be that the Roanoke and Salem areas are so heavily developed that there isn't a lot of room for change," he said.

Still, the state has documented the trend of the tick-borne disease, and health department officials said it isn't likely to reverse.

"We are seeing more Lyme disease in the state, regardless of where you are in Virginia," Remley said.

Cases of Lyme disease nearly tripled in 2007 to 945. Since then, the annual number of cases has remained above 900. Last year, there were 908 cases reported.

The reasons for the jump are not entirely known, Hall said.

Scientists theorize that changes in the variety of tick population, deforestation to build subdivisions and a strong acorn crop could all account for the rise in Lyme disease.

While some studies on the tick population have been conducted in other parts of the state, no research has been done the New River or Roanoke valleys, Gaines said.

But anecdotally, Gaines said he has documented changes in the tick population in the area.

Lyme disease is transmitted by the black-legged tick, or deer tick. The black-legged tick is one of three tick species in the state. The others are the lone star tick and the American dog tick. The lone star tick is by far the most common in the state, and for years was typically the species found in the New River and Roanoke valleys, Gaines said.

An avid hiker and rock climber, Gaines said he has spent years outdoors on the Appalachian Trail and in Southwest Virginia. Until recently, he had only had a couple of unique encounters with the black-legged tick.

"It seems that they became apparent starting around 2005, 2006," he said. "At least they became common enough to be reported to me by people I know. Which is quite a big change for all the hiking I've done and never having seen one."

Suburban sprawl is among the best theories Gaines has to explain the trend.

When developers move in and clear land that was once a forest or farm, it creates a perfect attraction for deer. Plus hunters are less likely to kill deer in the suburbs than they did on the farm or in the forest. Since the black-legged tick feeds and breeds on deer, changes to the deer population affect the tick population.

Recent development in Christiansburg could help explain the Lyme disease increase in Montgomery County, Gaines said.

Similarly, Gaines noted that the housing bubble in Virginia burst around 2007, just as the instance of Lyme disease spiked.

"There was probably an awful lot of development going on at that time and that may have contributed to an increase in the deer population," he said.

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