Myths & Facts

 MYTH: SERONEGATIVE LYME DISEASE IS COMMON

FACT: When properly performed and interpreted, serologic testing for Lyme disease is very useful. Almost all patients with Lyme disease are seropositive, especially if they are symptomatic for more than 2-3 weeks. Seronegative Lyme disease is extremely uncommon.

MYTH: NON-SPECIFIC ATYPICAL CHRONIC SYMPTOMS ARE COMMON

FACT: The clinical spectrum of Lyme disease has been well described. Relying on depression, anorexia, chronic fatigue, or “Symptoms compatible with Lyme disease”, or “Diagnosis by exclusion” usually results in poorly documented cases. Many patients so diagnosed do not in fact have Lyme disease. Most patients with Lyme disease present with objective findings on clinical examination or laboratory testing.

MYTH: LYME URIARY ANTIGEN TESTING (LUAT) IS USEFUL AND OFTEN POSITIVE WHEN ALL OTHER LABORATORY TESTS ARE NEGATIVE.

FACT: Urine antigen testing has not been validated. Its test performance characteristics are unknown and there is no published data to support its usefulness.

MYTH: BRAIN SPECT SCANNING IS USEFUL FOR DIAGNOSING LATE NEUORBORRELIOSIS, AND CAN BE “POSITIVE” FOR LYME DISEASE EVEN WHEN ALL OTHER LYME DISEASE TESTS ARE NEGATIVE.

FACT: There are no SPECT (or MRI) findings specific for neuroborreliosis. Non-specific abnormalities are seen in many Lyme and non-Lyme cases. There are no published controlled data showing specific SPECT finding in patients with well-documented Lyme disease compared to control patients.

MYTH: SCREENING ELISA TESTS SHOULD BE DONE TO PICK UP ASYMPTOMATIC OR ATYPICAL CASES.

FACT: ELISA testing is not 100% specific, and the positive predictive value is critically dependent upon the a priori likelihood of Lyme disease in the particular patient. Even in a highly endemic area, the vast majority of positive ELISA tests will be false positives when done as a screening procedure or when applied to patients with a low clinical suspicion of Lyme disease.

MYTH: ANY REACTIVITY ON WESTERN BLOTTING IS A POSITIVE TEST RESULT

FACT: There are many cross-reactive bacterial antigens. Proposed criteria for interpreting WB have been published, but this remains controversial. Faint or modest reactivity to some proteins at certain molecular weights is found in many healthy people, often reflecting cross-reactivity to remote other infectious exposures. Great care and experience are needed in the interpretation of Lyme WB results.

MYTH: CONVENTIONAL ANTIBIOTIC TREATMENT REGIMENS ARE OFTEN INEFFECTIVE AND ONLY LEAD TO TEMPORARY IMPROVEMENT. PROLONGED ANTIBIOTIC COURSES ARE USUALLY NEEDED.

FACT: There are no published controlled data supporting these more prolonged treatment regimens. Standard treatments are usually – but not always – effective, even for late Lyme disease. The natural history of adequately treated (cured) patients includes very slow but usually complete resolution of Lyme specific and associated non-specific symptoms. A NIH prospective, controlled, randomized study is now under way studying these persistently symptomatic patients and evaluating the effectiveness of more prolonged antibiotic therapy.

 

 


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