Lyme Disease Dr. Peter Dobie
Introduction • Lyme disease was named in 1977 when arthritis was observed in a cluster of children in and around Lyme, CN • Conditions suggested that this was an infectious disease probably transmitted by an arthropod • Further investigation revealed that Lyme disease is caused by the bacterium
CausativeOrganism • Borreliaburgdorferi • Loosely coiled spirochete • 8-20 micrometers
Ticks that cause Lyme disease Lone Star Tick Black-legged Tick Rocky Mountain Tick
Three Stages of Disease • Localized rash – erythema chronicummigrans • Dissemination to multiple organ systems • Chronic disseminated stage often with arthritic symptoms
Dissemination • Signs of early disseminated infection usually occur days to weeks after the appearance of a solitary erythema migrans lesion • Neurologic – Bell’s Palsy • Musculoskeletal manifestations may include migratory joint and muscle pains • Late disseminated Lyme disease is intermittent swelling and pain of one or a few joints.
ChronicDisseminated • Chronic arthritis • Chronic axonal polyneuropathy • Lyme disease morbidity may be severe, chronic, and disabling. • Rarely, if ever, fatal
Diagnosis • Diagnosed clinically, confirmed serologically. • Often appropriate to treat patients with early disease solely on the basis of objective signs and a known exposure. • CDC recommends testing initially with a sensitive first test, ELISA or an IFA test, followed by testing with the more specific Western immunoblot (WB) test to corroborate equivocal or positive results obtained with the first test.
Patients with early disseminated or late-stage disease usually have strong serological reactivity • Antibodies often persist for months or years following successfully treated or untreated infection. • Seroreactivity alone cannot be used as a marker of active disease Serology
IFA false positive may occur if patient has syphilis, relapsing fever or RA. • IFA interpretation highly subjective • EIA lacks sensitivity in early disease. • EIA false positives with syphilis, other treponemes, IM and autoimmune disease. Problems with Serology
Must be used if the Lyme IgG/IgM antibody serology is equivocal or positive • "Osp" refers to outer surface protein of the bacteria. • "kDa" is the abbreviation for "kilodalton," which is used for molecular weight designations. • Lyme antibodies of importance are against the following molecular weights of the B. burgdorferi antigens: 23-25 kDa (Osp C); 31 kDa (Osp A); 34 kDa (Osp B); 39 kDa; 41 kDa; and 83-93 kDa7. Western Blot
Single dose doxycycline shortly after tick bite. • Lyme disease give doxycycline followed by amoxacillin • Neuroborreliosis requires IV antibiotic therapy. Treatment
Address: SUITE 3A, EDGECLIFF COURT, 2 NEW McLean ST, EDGECLIFF, NSW 2027 Email: firstname.lastname@example.org Telephone: 02 9362 0493 Fax: 02 9363 0767 Dr. Peter Dobie Thank You