New clues about the bacteria that cause Lyme disease could lead to a novel strategy to reduce infections, according to a study to be published in mBio, the online open-access journal of the American Society for Microbiology, on December 4. The study reveals that the immune system of the white-footed mouse, a very common reservoir for Borrelia burgdorferi (the bacterium that causes the disease), responds differently to different strains of the bacterium, a finding that will help scientists tweak the animals' immune systems to prevent infection. A vaccine that keeps these wild mice free of the pathogen could significantly curb the spread of the disease from mice to ticks to humans.
"There's no human vaccine, and there's not likely to be one," says Alan Barbour of the University of California, Irvine, the lead author of the study. "We have to focus on lowering the risk. One way to do that is by treating the animals that carry the disease." Rabies offers a good example of how this might be accomplished, says Barbour. By deploying vaccine-laced food bait, public health officials have managed to lower the rabies infection rate in wildlife and significantly limited the spread of the disease to pets and humans.
Although Lyme disease only emerged in the U.S. in the past 40 years or so, around 25,000 cases are now reported every year in this country and the medical costs of these cases are estimated to range in the billions of dollars. Despite the growing importance of the disease, little is known about the evolution and ecology of the bacterium that causes the illness.
Barbour and his colleagues sought to understand why as many as 15 different strains of B. burgdorferi exist in the wild at differing degrees of prevalence. In the parts of the country where Lyme disease is most common, the majority of white-footed mice are infected with B. burgdorferi during the course of the year. Unlike humans and lab mice, white
|Contact: Jim Sliwa|
American Society for Microbiology