A team of scientists at Washington University in St. Louis has been keeping a wary eye on emerging tick-borne diseases in Missouri for the past dozen years, and they have just nailed down another part of the story.
They knew from earlier work that the animal reservoirs for the diseases included white-tailed deer, wild turkey and a species in the squirrel familiy, but the DNA assay they had used wasn't sensitive enough to identify the species.
Squirrels belong to a large family called the Sciuridae, which includes chipmunks, fox squirrels, red squirrels, flying squirrels, ground hogs and prairie dogs.
In the May issue of the Journal of Medical Entomology the scientists, led by Robert E. Thach, PhD, professor of biology in Arts & Sciences, report that a more sensitive assay has allowed them to identify the major species in question as the eastern gray squirrel.
Yes, the friendly neighborhood seed thief and dog tease is also a mobile tick blood supply and bacteria incubator.
The work is important because tick-borne diseases can be efficiently controlled only if all of the animal reservoirs that might contribute to transmission of the disease have been identified.
Not your New England tick
The most prevalent tick-borne disease in North America is Lyme disease, which is transmitted by the bite of an infected black-legged tick. In the southeastern United States, however, the most common diseases are ehrlichioses and STARI, which are transmitted by the bite of a different tick, the lone star tick.
Until 1986, ehrlichia bacteria were thought to cause disease only in animals. But in that year, a physician noticed mulberry-shaped aggregates characteristic of the bacteria in the blood of a gravely ill man.
The lone star tick, similarly, was thought to be merely a nuisance species until 1993, when the DNA of one of the ehrlichia species was found in lone star ticks collected
|Contact: Diana Lutz|
Washington University in St. Louis