Lyme Disease Association

Relaxing the case definition to provide greater leeway for clinicians who wish to treat patients for Lyme disease would be counter productive. As noted repeatedly by CDC, the surveillance case definition was developed for national reporting; it is not intended as a surrogate for sound clinical judgment. It would be contradictory for CDC to reaffirm this principal in response to suggestion #1 above, and at the same time relax the case definition for the purpose of making it fit the practices of individual health care providers.

Family, it is important to recognize that surveillance case definitions are not edicts issued by CDC. States voluntarily share information on selected diseases with CDC with the understanding that CDC will compile and disseminate this information for the nation as a whole. Although CDC general1y has input into determining which conditions will be reported, the final decision rests with the Council of State and Territorial Epidemiologist (CSTE). In 2001, at the request of Congress, CDC staff attended the CSTE annual meeting in Oregon and raised the concept of altering the Lyme disease case definition. This suggestion was not supported by CSTE. Indeed, representatives from only two states were in favor of changing the definition, and both proposed making it more restrictive, not less.

In summary, surveillance case definitions have a very specific purpose that is distinct from clinical diagnosis. We believe that relaxing the surveillance case definition is not needed.

3. CDC should institute a tick reduction program to assist with the reduction of the number of ticks, including grants for collegiate students to study in this area given pipeline issues.

CDC has maintained an active extramural and intramural program to develop and apply novel methods for controlling the ticks that transmit Lyme disease spirochetes. This is an extremely important component of our overall Lyme disease prevention program. Over a 13 year period, CDC has funded numerous Cooperative Agreements aimed at promoting tick control methodologies. These include landscape management approaches, least toxic pesticides, biological control agents, traditional area-wide acaricides, host targeted acaricides, and the development of anti-tick vaccines. Most importantly, the use of these methods in an integrated fashion as part of an Integrated Pest Management (IPM) strategy has been an important component of our program. Through our Community Prevention projects (currently funded in 4 states: CT, MA, NJ, and NY), pest management professionals have been trained to conduct the most safe and effective means of tick control in several communities highly endemic for Lyme disease.

Our intramural program to promote novel means for tick control has resulted in 2 major efforts: host-targeted bait boxes that kill ticks on rodents, and the testing of natural forest products that have significant activity against ticks as both acaricides and repellents. Both of these approaches have resulted in patents and hold promise for future development and widespread use by commercial entities to further the national effort to prevent Lyme disease.

CDC realizes the prime importance of training the next generation of scientists to lead the fight against vector borne disease in general and Lyme disease in particular. Toward that end, CDC has funded a total of 4 training programs at academic institutions (Colorado State University, University of Texas Medical Branch at Galveston, Tulane University, and Yale University) to train young scientists in the important field of vector borne disease. Training of students interested in the biology of tick borne diseases and Lyme disease prevention is ongoing through these important awards.

4.CDC should provide additional research funding to examine alternative transmission routes of Lyme disease including other animal vectors, sexual transmission and trans-placentaI transmission.

Transmission of Lyme disease through alternate mechanisms has been investigated in a series of studies. To date, these studies have not yielded clear evidence for such transmission.

While alternate modes of transmission remain theoretically possible, it is clear that the great majority of Lyme disease cases are due to tick-borne transmission. Given limited resources, we feel it is prudent to focus resources on preventing illnesses due to known modes of transmission rather than diverting them to evaluate rare or non-viable alternate routes. Gains made in preventing primary infection through tick bites will also necessarily reduce any risk of illness that might exist due to secondary (sexual and transplacental transmission.

5. CDC should provide justification for why CDC spends so much money on WNV and very little on Lyme disease.

Like other federal agencies, CDC's budget is allocated by Congress. Congress appropriated $7.4 million in 2002 and $7.1 million in 2003 for Lyme disease.

CDC first received a congressional appropriation of $4 million for the newly recognized West Nile virus (WNV) in FY 2000.

CDC and NIH should work together to ensure that PCR tests are accepted as diagnostic tests (not just ELISA and Western blot in the two-tiered process under CDC's case definition for surveillance).

Scientific studies, many of them funded by NIH or CDC, already have established the utility of PCR as a diagnostic test for Lyme disease. Evidence from well-conducted research published in the peer-reviewed scientific literature indicates that PCR can identify DNA that reflects active or recent infection by Lyme disease bacteria. For example, PCR of joint material, either synovial fluid or synovial membrane, can clarify whether a patient with persistent or recurring signs and symptoms of Lyme arthritis has an ongoing infection with Borrelia burgdorferi. These patients, a small subset of all people who develop Lyme arthritis, have a characteristic clinical picture and almost invariably also have other positive laboratory findings, particularly positive tests for serum antibodies to Lyme disease bacteria. In the case of chronic Lyme disease, patients in the largest placebo-controlled clinical trial of prolonged antibiotic therapy undertaken to date were all evaluated by PCR. Of 115 patients tested a total of more than 450 times at baseline and during the course of treatment, none were PCR positive. PCR testing was ncluded in the protocol of this study to make sure that anyone with a positive result received antibiotics and was not randomly assigned to the control group. The striking finding from this study precaution was that positive PCR tests must be very rare in patients with chronic disease and, therefore, is of very limited value in assisting physicians to diagnose this illness. The benefit of routine PCR testing of patients with chronic Lyme disease would be extremely small and such a practice would add greatly to the expense of diagnosing Lyme disease. It would divert scarce economic resources and add to health insurance costs.

There are no FDA-cleared PCR test kits for Lyme disease and the College of American Pathologists does not offer a proficiency testing program for PCR diagnostics of this disease, reflecting the niche position PCR plays in the spectrum of appropriate laboratory methods. Physicians ordering PCR tests must rely on the self-reported performance of individual laboratories. It is well-known that the exceptionally high sensitivity of PCR creates unique challenges in quality control. PCR findings must be interpreted in the context of the entire clinical picture of the patient.