tick borne infections

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  • 1. 1Tick BorneInfectionsDaniel J Anderson, MDEpidemiologyEcologyClinical CharacteristicsDiagnosisTreatmentPrevention

2. 2Tick-Borne InfectionsChallengesExpanding / changing geography of ticks / infectionsNew infections / newly recognized old infectionsNewly identified -- new Ehrlichia species 2011Old infections | new to MN -- Powassan fever, RMSFClinical clues that might suggest tick-borne infectionFever plus [rash, severe headache, mild hepatitis]low blood cell counts [esp platelets]]Diagnostic tests -- blood smear, serology, PCRDaniel J Anderson, MD 3. 3EpidemiologyEcologyClinicalDiagnosisDifferential DiagnosisDaniel J Anderson, MD 4. 4EPIDEMIOLOGYTick Borne Infections - MN/WIDaniel J Anderson, MD 5. 5Lyme diseaseAnaplasmosisEhrlichiosisBabesiosisPowassan FeverRMSF (Rocky Mountain Spotted Fever)Tick Borne Infections - MN/WIDaniel J Anderson, MD 6. 6Tick Borne Infections - MNDaniel J Anderson, MDLyme1,293 cases in 2010(21 % increase from 2009)Anaplasma720 cases in 2010( > 100 % increase from 2009)Ehrlichia New species of Ehrlichia reported 2011Babesia 56 cases in 2010 (31 in 2009)Powassan(50 cases in all of US 1958-2009 )6 MN cases 2008 - 20101 MN death from Powassan 2011 (at ANW)RMSF2000 cases / year in all of USSporadic cases in MN1 death in MN 2009 7. 7Daniel J Anderson, MDhttp://www.health.state.mn.us/divs/idepc/diseases/lyme/highrisk.htmlRisk of Tick-borne infection is notuniform throughout the state.The highest risk is central and SEsections 8. 8Daniel J Anderson, MDMore Anaplasma than Lyme inAitkin, Beltrami, Cass, Crow Wing& Hubbard countiesThe risk of different tick-borneinfections also is not uniformthroughout the state 9. 9RMSF annualincidence isincreasingDaniel J Anderson, MD 10. 10EcologyTick Borne Infections - MN/WIDaniel J Anderson, MD 11. 11Ticks DiseasesDaniel J Anderson, MDTICKIxodes scapularisAnaplasmosisLyme diseaseBabesiosisPowassan FeverAmbyloma americanumEhrlichiosisRMSFSTARITularemiaDermacentor variabilisDermacentor andersoniRMSFTularemiaDISEASEORIGINEndogenousImported(returning from travel) 12. 12Comparisonof ticksLyme, Anaplasma, Babesia, PowassanEhrlichia, STARI, Tularemia, RMSFRMSF, TularemiaDaniel J Anderson, MD 13. 13Blacklegged tick (Deer Tick)Ixodes scapularisLyme, Anaplasmosis,Babesiosis,& PowassanDaniel J Anderson, MD 14. 14Lone Star tickAmblyoma americanumEhrlichia, RMSFSTARI, TularemiaDaniel J Anderson, MD 15. 15American dog tickDermacentor variablisRMSF, Tularemia,Human Monocytic EhrlichiosisDaniel J Anderson, MD 16. 16Brown dog tickRhipicephalus sanguineusRMSFDaniel J Anderson, MD 17. 17ClinicalTick Borne Infections - MN/WIDaniel J Anderson, MD 18. 18Tick Borne IllnessesFever, chills, myalgias, arthralgiasFever, chills, rashFever, chills, CNS findings(encephalitis / paresis / paralysis / focal findings)Hepatitis / transaminitisLeukopenia, thrombocytopenia, anemiaDaniel J Anderson, MD 19. 19Diagnostic Clues / HintsAppropriate Exposure PotentialSuggestive SymptomsFever, rash, arthralgias, headache, neurologic findingsExamRash, splenomegalyLabsLow peripheral blood cell counts (esp thrombocytopenia)Mild transaminitis / hepatitisBlood smear, serologies, nucleic acid based tests (NATs)CSF analysisDaniel J Anderson, MD 20. 20Lyme3-30 days after tick bite (BEFORE fever)Erythema migrans (EM)70 - 80 % of patients get rashSTARIVery similar to Lyme diseaseexpanding Bulls Eye lesionsRMSF90 % -- usually 2 - 5 days AFTER feverInitially small pink macules on wrists /anklesLATER petchialTularemia Skin ulcer w regional lymphadenopathyRASHDaniel J Anderson, MD 21. 21Hgb Platelets LFTs WBCLyme DiseaseRMSF anemialowplateletstransaminitis leukopeniaAnaplasmosisEhrlichiosisBabesiosisPowassanFeveranemia transaminitisleukopeniathen leukocytosisDaniel J Anderson, MD 22. 22Lyme DiseaseDaniel J Anderson, MD 23. 23LymePathogen. Borrelia burgdorferi (spirochete)ClinicalEM rash, Bells palsy, AV block, CNS, ArthropathyCo-infection -- ~ 5-10 % with Anaplasma || ~ 2 % with BabesiaDxIgM: HGA can cause false + IgM for LymeIgM can persist for years (even if no clinical disease)After 8 weeks, should always have + IgGTreatment -- no data for prolonged therapyPrevention -- Doxycycline 200 mg if engorged tick < 72 h after biteDaniel J Anderson, MD 24. 24Lyme DiagnosisClinical diagnosis (ie no serology needed) if exposure to deer tick ANDBilateral Bells PalsyIII AV block or complete heart block [CHB]Characteristic erythema migrans [EM] rashDaniel J Anderson, MD 25. 25Daniel J Anderson, MD 26. 26Lyme SerologyCriteria for positiveWestern blot IgG 5 bandsWestern blot IgM 2 bandsChronologyEarly IgM +After 4-8 weeksnearly all IgG + (regardless of RST test strain used)SO, if IgG still negative > 8 weeks illness, then + IgM is false +IgMHGA can cause false + IgM+ IgM can persist for years ... may NOT correlate at all w clinical stateDaniel J Anderson, MD 27. 27Lyme Testing:Unvalidated tests with unproven useTest assays whose accuracy and clinical usefulness have not beenadequately established. Unvalidated tests available as of 2011include: Capture assays for antigens in urine Culture, immunofluorescence staining, or cell sorting of cell wall-deficient or cystic forms of B. burgdorferi Lymphocyte transformation tests Quantitative CD57 lymphocyte assays Reverse Western blots In-house criteria for interpretation of immunoblots Measurements of antibodies in joint fluid (synovial fluid) IgM or IgG tests without a previous ELISA/EIA/IFADaniel J Anderson, MD 28. 28Lyme PCRMost useful for late arthritis ifdone on synovial fluidLimited use in CSFDaniel J Anderson, MD 29. 29Lyme Disease TreatmentOral Therapy for all except neurological / latearthritis or initially for high degree AV blockIV therapy: for meningitis, late arthritis or initiallyfor high degree AV blockDaniel J Anderson, MD 30. 30Lyme Disease Rx Duration2-3 weeks for most early infections - thosome data suggest 10 days sufficient2-4 weeks for meningitis / arthritis4-8 weeks for late arthritisProlonged courses of therapy? .No proven benefitThere are proven adverse consequences(C diff, death, IV clots, ...)Daniel J Anderson, MD 31. 31Lyme DiseaseTreatmentReinfection rate rare (approximately 4 %)Post Exposure Prophylaxis (PEP) -single dose doxycycline 200 mg if < 72 hoursDaniel J Anderson, MD 32. 32AnaplasmosisDaniel J Anderson, MD 33. 33Human Granulocytic Anaplasomsis [HGA]Pathogen Anaplasma phagocytophilumClinicalup to 35 % coinfected with Lyme and/or Babesiafever, chills, headache, myalgia, and malaise,cough, diarrhea, confusion,and lymphadenopathy,17 % severe multisystem organ failure / SIRS / even death (Lyme does notdo this)rash is not commonDataleukopenia, thrombocytopenia,mild hepatitis / transaminitisDaniel J Anderson, MD 34. 34Human Granulocytic Anaplasomsis [HGA]DxPeripheral blood smear (in WBCs)30 - 80 % + morulaeseen in granulocytesSerologyNATs (PCR)TreatmentDoxycycline (will also cover potential Lyme coinfection)Daniel J Anderson, MD 35. 35EhrlichiosisDaniel J Anderson, MD 36. 36Human Monocytotropic Ehrlichiosis[HME]PathogensE canis / E chaffeensis / / E murisClinical< 50 % with rash (but more often than with HGA)More common farther south than Anaplasmosis (HGA)Data -- Lymphopenia, morulae RARE on blood smear (vs HGA)Dx -- Serology, PCRTreatment - doxycyclineDaniel J Anderson, MD 37. 37Daniel J Anderson, MDAnaplasmosisHGAEhrlichiosisHMEFarther northMN & WIFarther southIowa & Missouri~ 50 % morulaeon blood smearRARELY seemorulae in blood smearrash is RARErash more common(though still < 50 %)serology / PCRblood smearserology / PCRdoxycycline doxycycline 38. 38BabesiosisDaniel J Anderson, MD 39. 39BabesiosisPathogen Babesia microtii (MN, WI, East coast), B divergens & Bduncani in other locationsClinicalfatigue/weakness/malaise followed within days by fever(>38C) and one or more of the following: shaking chills,sweats, headache, myalgia, arthralgia, and anorexiaMalaise, myalgia, arthralgia, and shortness of breathdifferentiate babesiosis from other febrile illnessesfatigue and malaise persist for several monthsDaniel J Anderson, MD 40. 40BabesiosisDiagnosisBlood smear (in RBCs)Tetrad of ring formsMaltese CrossSerologyPCRTreatmentMild: atovaquone + azithromycinSevere: clindamycin + quinine + exchange transfusionDaniel J Anderson, MD 41. 41Less CommonDaniel J Anderson, MD 42. 42Powassan EncephalitisPathogen: FlavivirusSame viral family as Dengue, Yellow Fever, West NileClinical50 % w focal neurologic signs / symptomsOlfactory hallucinations & temporal lobe seizures (DDx Herpesencephalitis)Daniel J Anderson, MD 43. 43Powassan EncephalitisDataLeukopenia first (the high WBC), thrombocytopenia,transaminitisCSF lymphocytosis (usually < 100 cells)MRI => thalamic, basal ganglia lesionsDx => IgM (serum / CSF) /4 x increase serum IgGTreatment => supportiveDx => serologic (some cross reactivity with other flaviviruses (forexample Dengue fever)Daniel J Anderson, MD 44. 44RMSFPathogen Rickettsiae rickettsiiClinical (2 - 14 day [median 7] incubation)fever, headache, nausea / emesis / diarrhearash usually ~ 3 days AFTER other signsbegins wrists / anklesDatathrombocytopenia (sometimes anemia) WBC often nlcoagulopathy, DIC, CXR changesDx serology (? PCR on clinical specimens)Treatmentdoxycycline early in course illnessDaniel J Anderson, MD 45. 45DifferentialDiagnosisTick Borne Infections - MN/WIDaniel J Anderson, MD 46. 46Differential DiagnosesParalytic illnessesPolio, Tick Paralysis, Guillain-Barr, Cervical cord lesionEncephalitidiesHerpes simplex encephalitis (HSE) -- critical diagnosis becauseof the urgent need for intravenous acyclovir for HSEFebrile illnesses with rashParvovirus B19, Measles, Meningococcal disease, othersFever with transaminitisLyme, HGA, Babesiosis, Acute hepatitis (HBV, HAV, HCV)Daniel J Anderson, MD 47. 47DiagnosisDaniel J Anderson


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