Scratching the surface

National Report — Pain. Numbness. Weakness. Palpitations. These symptoms can be indicative of a variety of conditions, but sometimes the accurate diagnosis is bartonellosis, a chronic infection veterinarians have an elevated risk of contracting.

Bartonellosis manifests in humans as cat-scratch disease due to a strain seen in and passed from felines. Human medicine has much to learn about the condition, says Bobak Robert Mozayeni, MD, a leading expert on Bartonella.

"We are about to enter an era that awareness of chronic infection and its role in human disease is just beginning to emerge," he says. Those with Bartonella can often be misdiagnosed as having chronic Lyme disease, which similarly manifests, though the two are distinct.

Bartonella affects the microcirculation, and, in turn, can cause neurological symptoms. Mozayeni says patients tend to have both central and peripheral nervous system neurological issues, such as palpitations, severe pain, numbness and weakness. Often, adult patients will have acne on their upper face and forehead or get rashes, folliculitis on their upper arms and red stretch marks.

Since no large-scale research or clinical trial has been conducted related to Bartonella infections, many doctors don't diagnose it. As a result, patients as far away as California come to Mozayeni's Rockville, Md., practice for a consultation. "I've diagnosed and treated almost 200 patients and tested 500," he says. "A couple hundred have been through or are in treatment. Even when you develop experience like this, it's not enough to convince other doctors."

Mozayeni has many patients who are DVMs because of his work in this area. Veterinarians are at higher risk of contracting the disease because of their exposure from animals. "From my point of view, it's a pleasure to work with DVMs as patients," he says. "They get it; understand it; know what needs to be done with no medical legal paranoia. They have a vested interest in getting well, understand antibiotics and the potential side effects."

Some of the advice on treatment coming from his colleagues, however, is disconcerting, he says. Some of his other patients have had doctors halting treatment due to potential side effects. But Mozayeni contends that the treatment not only works, but he hasn't seen damage to patients' kidneys and livers. "Ninety-five percent of patients respond to treatment, and all in the same way," he says. "None of the antibiotics we have used have created liver or kidney trouble in any of several hundred patients I've treated. We check the lab work once a month, and typically all we see is a white-count lowering, which is likely attributed to the infection being treated."

Most patients receive a six-month course of antibiotic treatment, though Mozayeni is uncertain about the potential for relapse. "In dogs, there is a 15 percent relapse rate even after six months of treatment, but we need to do formal studies to answer these questions (on the human side)," he says. "But because it's so new, it's hard to get anyone's attention."

Mozayeni says the lack of awareness stems from a long-standing attitude that Bartonella is a veterinary disease and not a human one, but now that more and more cases are emerging, heads are starting to turn. "This is how translational medicine goes. There's a lone voice heard," he says. "What you have to count on is the open-mindedness of your colleagues, and that's not a common thing."

Nevertheless, Mozayeni hopes his work will grab enough attention that a large-scale clinical trial can take place to answer many questions about the condition itself and treatment. But, he concedes, "Generally speaking, most physicians are late adopters for major thought change."