Tracking Lyme Disease in Dogs May Help Protect Humans
Excerpted from Newsday ( Posted: 08/10/2011)
Since dogs are also susceptible to Lyme disease, they can be a good indicator of the risk of human infection, the scientists from the U.S. Centers for Disease Control and Prevention said. When blood tests show that few dogs in a given area carry the bacteria, the risk to people is relatively low, they noted. Conversely, when more dogs test positive for Lyme, people may be at increased risk, they noted.
“Public health authorities could use this to assess and evaluate changes in their region,” said Dr. Gary P. Wormser, chief of infectious diseases at New York Medical College and Westchester Medical Center in Valhalla. “This could be of help in understanding the risk areas for humans.”
The report, released Aug. 10, is published in the September issue of the CDC journal Emerging Infectious Diseases.
For the study, a team led by Dr. Paul Mead, a CDC medical epidemiologist, used data from 46 states on human and canine Lyme disease prevalence.
Comparing the data, Mead’s team found that when 1 percent or less of the dogs tested positive for Lyme disease, the risk of people becoming infected was low. However, when more than 5 percent of the dogs were infected, the risk to people was high.
A 5 percent (or higher) rate of positive blood test results in dogs “can be a sensitive but nonspecific marker of increased risk for human Lyme disease,” the researchers wrote in a CDC news release. “Because dogs do not transmit infection directly to humans [or humans to dogs], this association reflects similar susceptibilities to tick-borne infection.”
Sometimes, this level of canine infection “appears to anticipate increasing rates of human infection at the county level. Conversely, canine [prevalence of 1 percent or less] is associated with little to no local risk for human infection,” Mead’s group concluded.
For the complete article: http://www.newsday.com/news/health/tracking-lyme-disease-in-dogs-may-help-protect-humans-1.3087765