Text of Lyme Disease/ Lyme Borreliosis - CSU Bakersfield
Lyme Disease.pptBy Simone By Simone SwanepoelSwanepoel OutlineOutline Taxonomy/ History / Life cycleTaxonomy/ History / Life cycle Morphology of agents involved/ Epidemiology &Morphology of agents involved/ Epidemiology & DistributionDistribution Ecology / Evolution / Genetics / Physiology/ImmunologyEcology / Evolution / Genetics / Physiology/Immunology Parasite/host relationshipsParasite/host relationships Future ResearchFuture Research Leading arthropod-associated disease in theLeading arthropod-associated disease in the USAUSA 24, 000 human cases reported in USA (~10 % of24, 000 human cases reported in USA (~10 % of physician diagnosed cases)physician diagnosed cases) 12 states 12 states –– 95 % of cases (CDC 2005) 95 % of cases (CDC 2005) Greatest incidence~Children under 14 & adultsGreatest incidence~Children under 14 & adults over 40over 40 Summer Months ( Morshed et al. 2005)Summer Months ( Morshed et al. 2005) Multisystem disorderMultisystem disorder Great imitator ~ myriad of symptomsGreat imitator ~ myriad of symptoms TaxonomyTaxonomy Pathogen/CausativePathogen/Causative spirochetal bacteriaspirochetal bacteria (Barbour 1984)(Barbour 1984) Borellia burgdorferiBorellia burgdorferi Principal vectorPrincipal vector ~ ~ - Ixodes scapularis - Ixodes scapularis (blacklegged tick/(blacklegged tick/ ‘‘deerdeer’’ tick/hard tick) tick/hard tick) & & Ixodes PacificusIxodes Pacificus (Padgett and Lane(Padgett and Lane 2001)2001) Figure1. B.burgdorferi bacteria (CDC)Figure 2. Larva, nymph, male and female I. scapularis (CDC). TaxonomyTaxonomy Principal reservoir ~Principal reservoir ~ (nymphs) (nymphs) -White footed mouse-White footed mouse - - Peromyscus leucopusPeromyscus leucopus Principal host ~Principal host ~ (adults)(adults) -White-tailed deer, -Odocoileus Life CycleLife Cycle Life CycleLife Cycle Figure 6. Seasonal activity of I. scapularis larvae, nymphs, and adults (CDC). Figure 5. The enzootic cycle of B. burgdorferi infection in the northeastern US and intersection with human Lyme disease (Journal of Clinical Investigation 2004.) Natural HistoryNatural History 1764 - Reverend Dr John Walker1764 - Reverend Dr John Walker 1975 - Disease first recognized as a1975 - Disease first recognized as a clinical entity clinical entity –– Lyme, Connecticut (WHO) Lyme, Connecticut (WHO) 1981 - Causative bacteria discovered - Dr.1981 - Causative bacteria discovered - Dr. Willy BurgdorferiWilly Burgdorferi –– Long Island, New York.Long Island, New York. Extensive History in Europe Extensive History in Europe –– 20 20thth Century Century Morphology of Morphology of IxodidaeIxodidae Figure 7. Hypothetical Male and Female Ixodidae (hard ticks) with key characteristics labeled (CDC). Tick BitesTick Bites Figure 8. Scanning electron micrographs of the mouthparts of the blacklegged tick (CDC) EpidemiologyEpidemiology Figure 9. Reported cases of Lyme Disease in USA ~ 2005 (CDC). DistributionDistribution Tick VectorTick Vector Figure 10. Distribution of the tick species associated with human granulocytic anaplasmosis (HGA), I. scapularis, I. pacificus; and human monocytotropic ehrlichiosis (HME), A. americanum (CDC). Ecology & EvolutionEcology & Evolution UrbanizationUrbanization Anthropogenic factorsAnthropogenic factors B.burgdorferi ~ B.burgdorferi ~ highhigh strain diversitystrain diversity Genetic & PhysiologicalGenetic & Physiological AspectsAspects Genome Sequencing (Steere et al. 2004).Genome Sequencing (Steere et al. 2004). Spirochetes- Change of OpsA to OpsCSpirochetes- Change of OpsA to OpsC outer surface protein for mammalianouter surface protein for mammalian infection.infection. Spirochete bind mammalian plasminogen.Spirochete bind mammalian plasminogen. Surface protein of Surface protein of B.burgdoferB.burgdoferi - C6i - C6 peptide of the VslE protein antigen-peptide of the VslE protein antigen- immune responseimmune response ImmunologyImmunology Figure 12. Host mechanisms of spirochetal killing (Journal of Clinical Investigation 2004). ParasitismParasitism Obligate blood-feeders (ticks)Obligate blood-feeders (ticks) Require animal host to survive &Require animal host to survive & reproducereproduce Wide host range (people/pets/livestock)Wide host range (people/pets/livestock) Depends on host for nutritionalDepends on host for nutritional requirementsrequirements Clinical signs & symptomsClinical signs & symptoms Early localized/Early localized/ disseminateddisseminated infectioninfection CharacteristicCharacteristic Erythema MigransErythema Migrans rash (EM rash)/ bulls-rash (EM rash)/ bulls- eye rasheye rash Flu-like SymptomsFlu-like Symptoms Acute neurological/Acute neurological/ cardiac/ ocular cardiac/ ocular symptomssymptoms Brain & nervesBrain & nerves (neurological(neurological symptoms), eyes,symptoms), eyes, joints (arthritis) andjoints (arthritis) and heart.heart. Figure 11. Characteristic bulls-eye rash Diagnosis & Treatment ofDiagnosis & Treatment of Disease/SymptomsDisease/Symptoms EM rashEM rash Difficult to diagnoseDifficult to diagnose Over/underOver/under diagnoseddiagnosed Blood test Blood test –– antibodiesantibodies ELISAELISA Western ImmunoblotWestern Immunoblot (Assous et al. 1993) (Assous et al. 1993) False positive/False positive/ negative (PCR)negative (PCR) Techniques improvingTechniques improving Antibiotics ~Antibiotics ~ (including(including tetracyclines/ mosttetracyclines/ most penicillins, and manypenicillins, and many second- and third-second- and third- generationgeneration cephalosporins).cephalosporins). Early treatmentEarly treatment Figure 12 . An algorithm for the diagnosis and treatment of the early events surrounding Lyme disease in the summer months. Serologic testing for Lyme disease has limited utility during the first 1 or 2 weeks of infection, and early treatment, without serologic testing, is recommended (Journal of Clinical Investigation 2004.) PreventionPrevention Pesticides (acaricides) / InsectPesticides (acaricides) / Insect repellantrepellant Create a tick-safe zoneCreate a tick-safe zone Avoid areas with lots of ticksAvoid areas with lots of ticks Keep ticks off skin-Check skinKeep ticks off skin-Check skin & clothes for ticks& clothes for ticks Biological Control Biological Control –– landscaping/integrated pestlandscaping/integrated pest management/ decrease deermanagement/ decrease deer populationpopulation Clothing ( light colors &Clothing ( light colors & protective)protective) Organic approach Organic approach –– Guinea Guinea fowlfowl VaccinationVaccination Chronic Lyme diseaseChronic Lyme disease Long term treatment in humansLong term treatment in humans VaccineVaccine Future- Lyme diseaseFuture- Lyme disease Figure 13. Reported cases of Lyme disease in the United States ~ 1991-2005 (CDC). ConclusionConclusion Taxonomy/ History / Life cycleTaxonomy/ History / Life cycle Morphology of agents involved/ Epidemiology &Morphology of agents involved/ Epidemiology & DistributionDistribution Ecology / Evolution / Genetics / Physiology/ ImmunologyEcology / Evolution / Genetics / Physiology/ Immunology Parasite/host relationshipsParasite/host relationships Future ResearchFuture Research Works CitedWorks Cited Assous M. V., D.Assous M. V., D. Postic, G.Postic, G. Paul, P.Paul, P. Névot and G.Névot and G. Baranton. 1993.Baranton. 1993. Western blot analysis of sera from Lyme borreliosis patientsWestern blot analysis of sera from Lyme borreliosis patients according to the genomic species of the according to the genomic species of the BorreliaBorrelia strains used as strains used as antigens. European Journal of Clinical Microbiology & Infectiousantigens. European Journal of Clinical Microbiology & Infectious Diseases12: 261-268.Diseases12: 261-268. Barbour A. G. 1984. Isolation and cultivation of Lyme diseaseBarbour A. G. 1984. Isolation and cultivation of Lyme disease spirochetes. Yale Journal of biology and medicine 57: 521-525.spirochetes. Yale Journal of biology and medicine 57: 521-525. Center for Disease Control And Prevention. 2009. Learn aboutCenter for Disease Control And Prevention. 2009. Learn about Lyme Disease. Accessed online atLyme Disease. Accessed online at http://www.cdc.gov/ncidod/dvbid/lyme/http://www.cdc.gov/ncidod/dvbid/lyme/ Morshed, M. G.,Morshed, M. G., J. D. Scott, K.J. D. Scott, K. Fernando, L. Beati, D. F.Fernando, L. Beati, D. F. Mazerolle,Mazerolle, G. Geddes, and L. A. Durden. 2005. Migratory songbirds disperseG. Geddes, and L. A. Durden. 2005. Migratory songbirds disperse ticks across Canada, and first isolation of the ticks across Canada, and first isolation of the LymeLyme diseasedisease spirochete, Borrelia burgdorferi, from the avian tick, Ixodes auritulus.spirochete, Borrelia burgdorferi, from the avian tick, Ixodes auritulus. Journal of Parasitology 91: 780-790.Journal of Parasitology 91: 780-790. Works CitedWorks Cited PadgettPadgett K. A., and R. S. Lane. 2001. Life Cycle K. A., and R. S. Lane. 2001. Life Cycle of of Ixodes pacificusIxodes pacificus (Acari: Ixodidae): Timing of (Acari: Ixodidae): Timing of Developmental Processes Under Field andDevelopmental Processes Under Field and Laboratory Conditions. Journal of MedicalLaboratory Conditions. Journal of Medical Entomology 38:684-693.Entomology 38:684-693. Steere A. C., J. Coburn and L. Glickstein. 2004.Steere A. C., J. Coburn and L. Glickstein. 2004. The emergence of Lyme disease. Journal ofThe emergence of Lyme disease. Journal of Clinical Investigation 113: 1093-1101.Clinical Investigation 113: 1093-1101. World Health Organization. 2009. LymeWorld Health Organization. 2009. Lyme Disease. Accessed online atDisease. Accessed online at http://www.who.int/topics/lyme_disease/en/http://www.who.int/topics/lyme_disease/en/