A North Carolina State University researcher has discovered that certain tick-borne bacteria may be responsible for some chronic and debilitating neurological illnesses in humans, particularly among people with substantial animal contact or arthropod exposure.
Dr. Edward Breitschwerdt, professor of internal medicine at NC State's College of Veterinary Medicine and adjunct professor of medicine at Duke University, studied the bacteria Bartonella to determine how long these bacteria induce active infection in humans. The most commonly known Bartonella-related illness is cat scratch disease, caused by B. henselae, a strain of Bartonella that can be carried in a cat's blood for months to years.
Cat scratch disease was thought to be a self-limiting, or "one-time" infection; however, Breitschwerdt's previous work discovered cases of children and adults with chronic Bartonella infections — from strains of the bacteria that are found in cats (B. henselae) and dogs (B. vinsonii subsp. berkhoffii).
In a study published in the September volume of the Journal of Clinical Microbiology, Breitschwerdt and colleagues from the Duke University Medical Center and the Centers for Disease Control and Prevention in Atlanta were able to detect one or more strains of Bartonella in blood samples from six patients suffering from a broad spectrum of neurological and neurocognitive abnormalities, including chronic migraines, seizures, memory loss, disorientation and weakness.
All of the patients in the study had both frequent tick exposure and significant animal exposure — some were veterinarians, others had grown up on farms or had occupations that kept them outdoors — and all of them suffered from chronic, debilitating neurological problems.
The patients were treated with antibiotics, and three of them saw marked improvement. In the other cases, improvements were minimal or short-term.
Breitschwerdt believes that his research offers hope — perhaps the identification of a specific infectious cause of chronic neurological disease and another potential avenue of treatment — for what could be a significant segment of the population.
"Bartonella has been described by some scientists as a 'stealth pathogen,'" he says. "Our research could lead to the elimination of what may be a silent and currently unrecognized epidemic among humans."
"Bartonella sp. Bacteremia in Patients with Neurological and Neurocognitive Dysfunction"
Journal of Clinical Microbiology, Sept. 2008
Authors: E. B. Breitschwerdt, R. G. Maggi, et al.
Abstract: We detected infection with a Bartonella species (B. henselae or B. vinsonii subsp. berkhoffii) in blood samples from six immunocompetent patients who presented with a chronic neurological or neurocognitive syndrome including seizures, ataxia, memory loss, and/or tremors. Each of these patients had substantial animal contact or recent arthropod exposure as a potential risk factor for Bartonella infection. Additional studies should be performed to clarify the potential role of Bartonella spp. as a cause of chronic neurological and neurocognitive dysfunction.
NC State University News Services