Deer Interventions May Reduce Overall Cases of Lyme Disease in the Future

Researching Methods to Reduce Cases of Lyme Disease

In addition to ongoing research into new medical treatments for Lyme Disease, there is important research going on to try to reduce or prevent cases of Lyme Disease.

Since Lyme Disease is caused by the black-legged tick whose primary host is the white-tailed deer, research into prevention centers around the deer. Here is a look at one study aimed at reducing populations of white tail deer for this purpose.

Photo : WikiCommons

The white-tailed deer is one of the main hosts of blacklegged ticks – the insect known to spread Lyme disease. For many years now, researchers have wondered whether reducing the deer can lower the disease risk. They finally have an answer. After conducting a study that span across a period of 13 years, researchers in Connecticut found that Lyme disease risk could indeed be lowered by reducing the number of white-tailed deer.

“We found that reducing deer density by 87 percent resulted in a significant reduction in tick abundance, nearly a 50 percent reduction in tick infection rate, and an 80 percent reduction in resident-reported human cases of Lyme disease,” the authors wrote in a press statement. “Our study demonstrated that deer populations can be manipulated to reduce human interactions with deer, infected nymphal ticks, and human risk of contracting Lyme disease.”

“Reducing deer populations to levels that reduce the potential for ticks to successfully breed should be an important component of any long-term strategy seeking to reduce the risk of people contracting Lyme disease,” the authors stated. “Additionally, good hunter access to deer habitat and a wide variety of management tools (bait, unlimited tags, incentive programs) are important components of a successful deer reduction strategy.”
– via Headlines & Global News

Other Deer Research to Prevent Lyme Disease

The excerpt below discusses two deer-targeted interventions that hold promise in preventing cases of Lyme Disease by reducing populations of black-legged ticks.

One method uses bait stations that treat the deer with a pesticide killing the ticks. The second method reduces the population of the white tail deer itself. Here are the discussions and their findings.

One study showed that more than 95% of adult female ticks feed on white-tailed deer. Nymphal ticks will also feed on deer.

Therefore, deer-targeted interventions could provide a large-scale method for controlling tick populations by reducing the number and movement of blacklegged ticks.

Two proposed deer-targeted interventions have included a topical acaricide applied using a four-poster device and deer-reduction programs.

However, few studies have evaluated whether deer-targeted interventions resulted in decreased LD incidence, particularly in non-island settings.

The four-poster device is a passive topical treatment system developed by the U.S. Department of Agriculture, Agricultural Research Services. A central bin stores and dispenses bait to attract deer. As the deer feeds, rollers apply an acaricide directly to the head, ears, and neck, which is transferred to other body areas by self-grooming.8 Studies of this device have shown a significant decrease in blacklegged tick abundance on deer and in the surrounding area.

Another deer-targeted intervention aims to reduce deer populations through a controlled deer hunt.

The results of the four-poster analysis showed a general decreasing trend in EM rash incidence in all areas

In the original treatment area, the mean incidence before treatment was 427.5 cases per 100,000 population (standard deviation [SD] = 94.2); after treatment, the mean incidence was 137.8 cases per 100,000 population (SD=80.6). The mean incidence was significantly different before and after treatment.

The four-poster results are consistent with other studies that showed the device was effective at reducing tick populations and with computer simulations suggesting that acaricidal treatment of deer would prevent the most cases of LD.

In Mumford Cove, reducing the number of deer did not have a significant effect on the reported EM rash incidence despite a significant decrease in tick abundance. There was a 45% decrease in mean EM rash incidence after treatment in the original treatment area and a 46% decrease after treatment in the relative rate of the original treatment area compared with the original control area. – via PubMed Central (PMC)

Do you live in an area with a large population of white-tailed deer?