By STEVE NERY
News Editor
March 19, 2008
Lyme disease advocacy groups believe a new study reinforces their position that traditional treatment does not effectively eliminate the disease.
A University of California at Davis Center for Comparative Medicine study (published online by the American Society for Microbiology) concludes that traditional treatment of Lyme disease did not kill all Borrelia burgdorferi spirochetes, the tiny organisms responsible for the disease, in mice in the lab. The study seems to back Lyme advocacy groups' contention that more intensive treatment may be needed at times, although the authors note that more studies are needed to determine the long-term fate of the surviving spirochetes.
Mice were treated with ceftriaxone (a drug commonly used to treat Lyme) or saline (the placebo) for one month, the maximum amount of time recommended by the Infectious Diseases Society of America (IDSA). Treatment started during the early stages three weeks after infection or chronic stage four months after infection.
Tissues of the mice were tested for infection by culture, polymerase chain reaction (during which DNA molecules are amplified for inspection), xenodiagnosis (testing whether clean samples become infected upon exposure), and allograft transplantation (in which organs are taken and put in another mouse). The tests were performed at one and three months after the completion of treatment. Tissues were also examined for spirochetes by immunohistochemistry, where researchers look for antibodies to mark the presence of the bacteria.
The mice treated with saline tested positive for the spirochetes by culture, whereas the mice treated with antibiotics were consistently culture negative. Some of the tissues from the mice treated by antibiotics, however, were PCR-positive, and ticks which fed upon those mice picked up the spirochetes. The ticks then went on to transmit the spirochetes to previously uninfected mice, which were also PCR-positive but culture-negative.
"Results indicated that following antibiotic treatment, mice remained infected with non-dividing but infectious spirochetes, particularly when antibiotic treatment was commenced during the chronic stage of infection," the abstract reads.
The authors write that further tests are needed to determine the eventual fate of the remaining spirochetes, which were found hiding in tissue at the base of the heart as well as in tendons or ligaments at joints.
The authors conclude that the overt disease may no longer be present following a month of antibiotic treatment, but the continued presence of B. Burgdorferi may contribute to the persistence of constitutional symptoms. The culture tests, the method favored by the IDSA, "cannot be relied upon as markers of treatment success," they write.
"This latest study once again proved the maximum recommended treatment for Lyme disease failed to eliminate the infectious agent. We need to treat Lyme disease patients until all of their symptoms are gone and not by some arbitrary, cost-effective, insurance friendly guidelines that aren't worth the paper they are written on," said Lucy Barnes, director of the Lyme Disease Education and Support Groups of Maryland.
Barnes is among those who advocate for the International Lyme and Associated Diseases Society (ILADS) treatment guidelines, which provide more flexibility than the Infectious Diseases Society of America's guidelines.
"People, especially children, are going to continue to get sick and stay sick if this disease isn't treated promptly and aggressively. This is another study proving what is being done for people with Lyme is totally inadequate in many cases," Barnes said.
Barnes also decried the ineffective testing method endorsed by the IDSA.
"If this was a test designed to detect cancer and 75 to 90 percent or more of the people who had cancer or HIV were missed, the public outcry would be horrendous. These standard Lyme tests that doctors are depending on to diagnose their patients must be pulled from the market immediately to prevent more harm. Physicians should be clinically diagnosing Lyme as the Centers for Disease Control recommends and treating it until the patients are better, as they would for any other infectious disease," she said.