Lyme Disease Background
The disease is caused by Borrelia burgdorferi, a spriochete sharing sequence homology with Treponema and Leptospira. Borrelia burgdorferi is the longest and narrowest of the Borreliae. It contains several antigens that are important in pathogenesis and diagnosis including outer surface proteins, OspA through OspG, that are located on plasmids and a 41 kDa flagellar protein. Although there are three geno-species recognized within the Borrelia burgdorferi (B. burgdorferi sensu lato): B. burgdorferi sensu stricto, B. garinii, and B. afzelii, strains found in the United States are relatively homogeneous and conform to the definition of B. burgdorferi sensu stricto. The two other species are present in Europe and Asia and produce mixed infections in humans and mice. B. garinii is mainly associated with neuroborreliosis whereas B. afzelii is associated with arthritis and skin lesions. The risk of developing LD following a tick bite is less than 0.01 and it has been shown that it is not cost-effective to recommend prophylactic treatment for everyone that has been bitten by a tick.
Like other spirochetal infections, the signs and symptoms of LD occur in stages and involve a variety of tissues and organs including the skin, joints, heart and nervous system. Early infection (stage 1) involves erythema migrans (EM), an annular skin rash that is seen days to weeks after a tick bite. Hematogenous dissemination of the bacteria days to weeks later (stage 2) can result in multiple skin lesions (secondary EM) as well as meningitis, rediculoneuritis, arterioventricular blockage, myocarditis and oligoarticular arthritis. Persistent infections (stage 3) occurs months to years following the initial exposure and can be associated with acrodermatitis chronica atrophicans, various encephalopathies and persistent arthritis. Clinical signs of LD among patients in North America tend to differ from those in Europe and Asia due to differences in Borrelia species in different parts of the world. The CDC has developed a case definition of LD for surveillance purposes that includes either physician-diagnosed EM along with solitary lesions of at least 5 cm or at least one joint, cardiac or neurological manifestation along with laboratory diagnosis.
Culture isolation of B. burgdorferi sensu lato remains the gold standard for diagnosis although the recovery rate decreases as the disease stages advance with the most likelihood of isolating the bacteria in Barbour-Stoenner-Kelly medium (BSK or modified BSK) is in stage one EM. Detection of the bacteria in culture is accomplished using dark field microscopy, or by fluorescent microscopy using acridine orange stain or a specific antibody to the bacteria labeled with fluorescein. Serologic testing using antibodies to outer surface proteins (OsP-A to G), the 41 KDa flagellin protein and other heat shock proteins can be used although there have been reports about down regulation of OsPs A-G in the bacteria after a blood meal. Molecular testing is being widely used for the detection of the spirochete in lesions even before the appearance of antibodies in the patient’s serum. It was shown that PCR has close to 99% specificity and an average of 73% sensitivity and that molecular testing produces positive results in cases where the patients had already received prophylactic treatment and no antibodies or viable bacteria have been detected. The bacterial DNA tends to be detectable by PCR in joints and tissues for weeks following antimicrobial therapy. The PCR results from cerebrospinal fluid (CSF) vary and the overall sensitivity in CSF does not exceed 20%, therefore, a negative result in the CSF does not rule out LD. Urine has been shown not to be a good sample choice for diagnosis as the results showed large variations. In conclusion, the most important element in LD diagnosis is the clinical picture and patient history supported by laboratory testing using several methods to improve sensitivity. It is highly recommended that PCR testing be performed as early as possible following a possible exposure to ticks. If the results are positive, prophylactic treatment can be recommended by a clinician and other testing is performed to monitor the treatment efficacy.
Lab tests for Lyme disease
According to the Infectious Diseases Society of America (IDSA), testing for Lyme disease should be based on the 2-tier testing algorithm recommended by the Centers for Disease Control and Prevention (CDC) and the Association of State and Territorial Public Health Laboratory Directors. The 2-tier algorithm uses an Enzyme Linked Immunoassay (ELISA) as the first tier and IgM and IgG immunoblots or Western blot as the second tier. The second tier is performed only if first tier testing is positive.
For more information on IDSA diagnostic guidelines click here.
For a sample Lyme by Western Blot Report click here.
Lyme disease and pregnancy
Transmission of Lyme disease from an infected mother to her child during pregnancy has been documented. The mother did not receive antimicrobial therapy during the course of her pregnancy and delivered an infant with a congenital heart defect (1). It is unknown if the heart defect was related to the Lyme disease in the mother.
Autopsy and clinical studies have associated gestational Lyme Borreliosis with various medical problems including fetal death, hydrocephalus, cardiovascular anomalies, neonatal respiratory distress, hyperbilirubinemia, intrauterine growth retardation, cortical blindness, sudden infant death syndrome, and maternal toxemia of pregnancy (2). Whether any or all of these associations are coincidentally or causally related remains to be clarified by further investigation.
Nineteen cases of Lyme disease in pregnant women were evaluated by the CDC and state and territorial epidemiologists in order to assess the risk of Lyme disease in pregnant women (3). Thirteen of the women received appropriate antibiotic therapy for Lyme disease. Although no cases of congenital heart defects were noted in the infants, 26 % of these pregnancies had adverse outcomes, to include second trimester fetal demise, prematurity and developmental delay with cortical blindness. The risk of adverse outcome for pregnancies complicated by Lyme disease is not currently known. This information was reported by State and Territorial Epidemiologists; Respiratory and Special Pathogens Epidemiology Br, Div of Bacterial Diseases, Center for Infectious Diseases, CDC.
For additional CDC information on Lyme disease and pregnancy click here.
- Schlesinger PA, Duray PH, Burke BA, et al. Maternal-fetal transmission of the Lyme disease spirochete, Borrelia burgdorferi. Ann Intern Med 1985 (in press).
- MacDonald AB. Gestational Lyme borreliosis. Implications for the fetus. Rheum Dis Clin North Am. 1989 Nov;15(4):657-77
- Markowitz LE et al. Lyme disease during pregnancy. JAMA. 1986 Jun 27;255(24):3394
Chronic Lyme disease
A 2012 study at the Tulane University National Primate Research Center demonstrated that Rhesus monkeys infected with B. burgdorferi and then treated aggressively with antibiotics were later seen to have intact spirochetes (1). Rhesus monkeys were chosen in part due to their ability to experience the most important symptoms of human Lyme disease including neuroborreliosis. The monkeys were treated with ceftriaxone and/or doxycycline according to guidelines established by the Infectious Diseases Society of America (IDSA). The presence of spirochetes was detected both by host analysis (detecting spirochetes in tissues by PCR) and by xenodiagnosis (ticks feeding on treated monkeys were later found to have spirochetes in their mid gut).
For the complete article click here
A 2008 study at the University of California at Davis showed that, in a mouse model of Lyme Borreliosis, mice treated with ceftriaxone for one month had evidence of the presence of infectious spirochetes in their tissues (2). The authors of this study also concluded that the presence of infectious spirochetes was particularly evident in mice treated during the chronic stage of infection.
- Embers ME, Barthold SW, Borda JT, Bowers L, Doyle L, Hodzic E, Jacobs MB, Hasenkampf NR, Martin DS, Narasimhan S, Phillippi-Falkenstein KM, Purcell JE, Ratterree MS, Philipp MT. Persistence of Borrelia burgdorferi in rhesus macaques following antibiotic treatment of disseminated infection.. 2012;7(1):e29914. Epub 2012 Jan 11.
- Hodzic E, Feng S, Holden K, Freet KJ, Barthold SW. Persistence of Borrelia burgdorferi following antibiotic treatment in mice. Antimicrobial Agents and Chemotherapy. 2008;52(5):1728–1736.
Lyme Disease and Autism
In one small study of boys who tested positive for Lyme disease and also exhibited symptoms consistent with Autism Spectrum Disorders, an improvement in Autism Spectrum Disorder symptoms was noted after a six month course of antibiotic treatment (1).
For more information on this study click here.
An article written by a psychiatrist highlights supportive reasons for the hypothetical Lyme disease and Autism connection (2). The reasons include multiple cases of mothers with Lyme disease and their children with autism spectrum disorders, fetal neurological abnormalities associated with tick-borne diseases, positive reactivity in several studies with autistic spectrum disorder patients for Borrelia, and improvement in autistic symptoms from antibiotic treatment.
For more information on this article click here
An overview comparing and contrasting Lyme disease and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS) was published in the International Journal of General Medicine (3). The authors note that although the two conditions are caused by different microorganisms with different somatic symptoms, both may involve similar pathologic mechanisms in the central nervous system which may initiate or exacerbate psychiatric conditions in children. One mechanism proposed was that antibodies that cross the blood brain barrier in both Lyme disease and PANDAS may cross-react with neuronal cells in the brain disrupting their function.
For more information on this study click here.
- Kuhn M, Grave S, Bransfield R, Harris S. Long term antibiotic therapy may be an effective treatment for children co-morbid with Lyme disease and Autism Spectrum Disorder. Medical Hypotheses 2012 February 21
- Bransfield RC, Wulfman JS, Harvey WT, Usman AI. The association between tick-borne infections, Lyme borreliosis and autism spectrum disorders. Med Hypotheses. 2008;70(5):967-74.
- Ree H, Cameron D. Lyme disease and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS): an overview. International Journal of General Medicine. 2012 February 21.Volume 2012:5 Pages 163 – 174