New brucellosis “hot spots” found in Yellowstone area
By MATTHEW BROWN, AP, R&D Online, April 24, 2010 [here]
The animal disease brucellosis is emerging in new “hot spots” around Yellowstone National Park, according to new research that could complicate efforts to control transmissions of the disease to cattle.
Feeding grounds where food is left for elk as well as herds of bison inside the park have long been considered the main sources of brucellosis, which causes pregnant animals to abort their young.
But Paul Cross with the U.S. Geological Survey said a third source is now emerging: Blood tests indicate large elk herds living far from the feeding grounds have brucellosis exposure rates ranging from 10 percent to 30 percent.
That means containing the park’s bison and getting rid of the feeding grounds might not be enough to stop brucellosis transmissions to cattle in Idaho, Montana and Wyoming.
The Yellowstone region has an estimated 100,000 elk and is the nation’s last reservoir for the disease. Over the last decade, cattle infections have appeared in all three states bordering the park.
“It’s no longer appropriate to say bison and the supplemental feed grounds are the only sources of contamination,” Cross said.
Cross was the lead author of a USGS study published online Friday by the Public Library of Science.
Co-authored by researchers from Wyoming Game and Fish, Montana State University and USGS, the study was based on more than 6,000 blood tests collected from Wyoming elk between 1991 and 2009.
Since the testing began, Cross said disease rates increased dramatically in two “hot spots” — north of Dubois, Wyo. and northwest of Cody, Wyo. Both of those areas are far from the state’s 23 artificial feeding grounds.
The study comes on the heels of another USGS report in March that found brucellosis rates on the rise across the region. Prevalence rates increased from between 0 percent and 7 percent in 1991-1992, to between 8 percent and 20 percent in 2006-2007. … [more]