Veterinary and human medical researchers link Bartonella to rheumatic disease

The bacterium Bartonella might be a culprit for more than just bartonellosis, or “cat scratch disease,” according to new research from North Carolina State University. Two researchers at the university, Ed Breitschwerdt, DVM, DACVIM, professor of internal medicine at NC State’s College of Veterinary Medicine, and Ricardo Maggi, PhD, research assistant professor, teamed up with Robert Mozayeni, MD, a rheumatologist in Maryland, to explore the possibility of Bartonella as a causative agent for human rheumatoid disease.

Bartonella henselae, commonly known to cause bartonellosis in humans, can be transmitted by biting parasites, such as ticks and fleas, as well as by a bite or scratch from an infected cat or dog. And because the symptoms of cat scratch disease in humans can mimic rheumatoid diseases, such as rheumatoid arthritis, the researchers decided to test blood samples from patients suffering from conditions such as Lyme disease, arthritis and chronic fatigue for evidence of Bartonella infection.

Of the 296 patients sampled, 62 percent had Bartonella antibodies, a strong indicator of previous exposure to the bacteria. In addition, bacterial DNA was found in 41 percent of the patient samples, allowing the researchers to positively identify which species of Bartonella was present. The most prevalent ones seen were B. henselae, B. kohlerae and B. vinsonii subsp. berkhoffii.

“Based upon this one study we can’t definitively say that a subset of rheumatoid illnesses have an infectious origin,” Breitschwerdt says. “However, our results thus far do implicate Bartonella as a factor in at least some cases. If the link between Bartonella and rheumatoid illnesses is valid, it may also open up more directed treatment options for patients with rheumatoid illnesses.”

The study results can be found in the May 2012 issue of Emerging Infectious Diseases.