Presentation on theme: "Vector-borne diseases"— Presentation transcript:
1Vector-borne diseases S. Sears, MDKnow what vectors are, environments (ticks – suburban environments)
2Lyme disease Multisystem inflammatory disease Causes by spirochetes Borrelia burgdorferiSpread by Ixodes ticksI. scapularisEastern,North central and Southern United StatesI. pacificusWestern United StatesI. ricinusEuropeI. persulcatusAsiaTransmissionBite of an infected nymph in the spring-really small, barely even know you’ve been bittenPreferred hostWhite-tailed deer
5Clinical manifestations Early localized diseaseOccurring few days to one month after the tick biteEarly disseminated diseaseOccurring days to 10 months after the tick biteLate or chronic diseaseOccurring months to years after the tick bite3 phase diseaseLate or chronic - arthritis
6Early localized disease Erythema migrans50-70% of patientsFoundNear axillaInguinal regionBehind the kneesBelt lineAsymptomaticMay burn or itchExpands over the course a few days with central clearingAssociated symptomsFatigueMalaiseLethargyHeadacheStiff neckMyalgiasArthralgiasLymphadenopathyEM – bulls eye rash
8Early disseminated disease Carditis : 8 -10% of patientsConduction defectsCardiomyopathy or myopericarditisNeurologic disease :10% of patientsLymphocytic meningitisEncephalitisCranial neuropathy (often bilateral facial)Peripheral neuropathyRadiculoneuropathyMyelitisMusculoskeletal involvement : 50% of patientsMigratory polyarthritisSkin involvementErythema nodosumLymphadenopathyEye involvementConjunctivitisIritisRetinitisVitritisChoroiditisHepatitisMicrohematuria with proteinuriaMost common is neurologic and carditits
9Late or chronic disease Musculoskeletal symptoms50% : migratory polyarthritis10% : chronic monoarthritis (knee)Neurologic disease (incidence not established)NeuroborrelosisEncephalopathyNeurocognitive dysfunctionPeripheral neuropathyEncephalomyelitisAtaxiaDementiaPsychiatric disturbancesCutaneous involvementAcrodermatitis chronica atrophicansMorphea (localized scleroderma-like lesions)Mostly arthralgias and arthritis, with neurologic disease
11Diagnosis Centers of Disease Control and Prevention criteria Presence of erythema migransORAt least one late manifestationPlus laboratory confirmationLate manifestations can include if not explained by another diseaseMusculoskeletal systemChronic arthritisNotChronic progressive arthritisChronic symmetrical arthritisFibromyalgiaNervous systemLymphocytic meningitisCranial neuritisEncephalomyelitisCSF confirmation of antibody against B. burgdorferiHeadacheFatigueparesthesiasUsually a musculoskeletal, joint disease, neurologic.Need to think about it.EM is pathognomonic
12Diagnosis Serologic tests Used to confirm the diagnosis Diagnosis make on clinical groundsTwo-rest step approachSensitive enyzme-linked immunosorbent assay (ELISA)Followed by Western immunoblotIf ELISA positive-test Western blotIf ELISA negative-no Western blotSame sample tested by each testIf < 4 weeks illness - IgM and IgG testedIf > 4 weeks illness - IgG testedSynovial fluid or CSFTested for the antibodies to B.burgdorferiAntibiotics in early disease may prevent seroconversionPrior vaccine interferes with the test (vaccine no longer available)
13Treatment Early disease Erythema migrans < 10% do not respond Do not use macrolidesFor areas also endemic for human ehrlichiosis use doxycyclineDoxycycline 100mg po bid for daysAmoxicillin 500mg po tid for daysCefuroxime 500mg po bid for daysDisseminated diseaseCardiacFirst degree AV blockDoxycycline 100mg po bid for daysLate diseaseCeftriaxone 2g IV daily for days
14Treatment Disseminated disease Neurologic disease Early Isolated facial nerve palsyDoxycycline 100mg po bid for daysAmoxicillin 500mg po tid for daysCefuroxime 500mg po bid for daysMore serious diseaseEarly or lateMeningitisRadiculopathyEncephalitisCeftriaxone 2 g IV daily for daysArthritisNo evidence of neurologic diseaseDoxycycline 100mg po bid for 28 daysAmoxicillin 500mg po tid for 28 daysCefuroxime 500mg po bid for 28 daysWith neurologic diseaseCeftriaxone 2g IV daily for days
15Outcome Treatment with standard antibiotics generally successful 10 % experience treatment failureNon-specific symptoms may lingerAsymptomatic seropositive patientsRecommendation not to treat
16Human ehrlichiosis Ehrlichiae Obligate intracellular bacteria Grow in membrane bound vacuolesHuman and animal leukocytesDiseasesHuman monocytic ehrlichiosis (HME)Caused by Ehrlichia chaffeensisHuman granulocytic anaplasmosis (HGA)Caused by Anaplasma phagocytophilumOccurs in spring and summerIn southeastern, southcentral,mid-Atlantic United StatesTick vectorE.chaffeensis - Lone star tick (Amblyomma americanum)A.phagocytophilum - Ixodes scapularisAnimal reservoirHME - white tail deerHGA - deer and white-footed mouseAfter tx for Lyme still had fever and such. Co-infection.These infect WBC – get flu etc, WBC ct goes down.Sicker than with Lyme
19Clinical manifestations Incubation period 1-2 weeks prior to presentation of symptomsFever can persist for 2 monthsNonspecificMalaiseMyalgiaHeadacheChillsNauseaVomitingArthralgiasCoughMaculopapular or petechial rashNeurologicMental status changesStiff neckClonusComplicationsSeizuresComaCongestive heart failurePericardial effusion
21Investigations Laboratory findings CSF lymphocytic pleocytosis LeukopeniaThrombocytopeniaAnemiaIncreased liver function testsCSF lymphocytic pleocytosisDiagnosisIndirect fluorescent antibody (IFA) testExamination of peripheral blood or buffy coatPCR for HME and HGAImmunochemical staining of ehrlichial/anaplasmal antigens in tissueNeed to think about it as a coinfection- fever and low white count
22Treatment Drug of choice Doxycycline IV or oral 100 mg bid for 10 days Intolerance to doxycyclineUse rifampin 300mg po bid for 7-10 days
23Outcome Mortality rates HME - 2 to 5 percent HGA - 7 to 10 percent Life-threatening diseaseIn patients co-infected with HIVSolid organ transplant recipientsPreventionTick repellantsTick removal
24Babesiosis Tick borne illness Protozoa of the family Babesiidae Animal reservoirRodents and cattleHuman diseaseDue to Babesia microtiEnters the red blood cells and causes hemolysisVectorIxodid tickOccurs northeast coast of the United StatesCan have triple infection.
29Treatment First-line treatment 7-10 days Dosing Severe disease Clindamycin-quinineOr atovaquone-azithromycinDosingAtovaquone mg po q 12 hrsAzithromycin mg po x1 then 250 mg po dailyClindamycin mg po tid or 300 mg IV qidQuinine mg po q6hrsSevere diseaseAntibioticsPlus exchange transfusionUntil parasitemia is < 5 percentOutcome is variable with level of disease
30Malaria Human malaria caused by species Plasmodia Predominates P. falciparumP. vivaxP. ovaleP. malariaePredominatesTropical AfricaSoutheast AsiaHaitiSouth AmericaDominican RepublicCentral AmericaMiddle EastIndiaTransmissionBite of Anopheles mosquitoCongenitalBlood transfusionContaminated needlesTransplantation
32Malaria All four malaria parasites Liver and spleen enlarge over time Digest red blood cell proteins and hemoglobinResults in hemolysis and increased splenic clearanceLiver and spleen enlarge over timeThrombocytopenia from increased splenic clearanceP. FalciparumForms stick knobsForms rosettesResults in obstruction of blood flowProtection against malariaSickle cell genetic alterationsAlpha thalassemiaBeta thalassemiaOvalocytesImmunityPartial immunity may occur in those in endemic areasVery common cause of infant mortality
33Cycle of malariaVivax and ovale can live a while in liver.
34Clinical manifestations Incubation period1-4 weeksSymptomsChillsSweatsHeadacheMyalgiasFatigueNauseaAbdominal painVomitingDiarrheaCoughSignsAnemiaThrombocytopeniaSplenomegalyHepatomegalyJaundiceSplenic ruptureSick for a while, quiet period, then get sick again
35Clinical manifestations P. falciparumAssociated with transient increases in HIV viral loadCerebral malariaImpaired state of consciousnessSeizuresRisk factorsAgePregnancyPoor nutritional statusHIV infectionPrior splenectomyComplicationsRenal failureARDSHypoglycemiaAnemiaBleedingGastroenteritisP. vivax and ovaleLiver forms-late relapsesP. malariaeGN from chronic immune complex formation and deposition
36Diagnosis Light microscopy Stained thick and thin blood smear Thick smearMalariaThin smearMorphologic featuresParasite density estimationFluorescent microscopyAntigen detectionPCR- DNA / RNA
38Treatment Supportive measures Antimalarial medications Mechanisms of antimalarial drugsQuinoline derivativesChloroquine,quinine,quinidine,mefloquineInhibit heme polymerase activityAccumulation of free heme is toxic to parasitesAntifolatesPyrimethamine,sulfonamides,dapsoneKill intrahepatic forms of the parasiteArtemisinin derivativesArtemisinin,artemether,artesunateProduce free radical that damage parasite proteinsAntimicrobialsClindamycin,atovaquone,tetracyclinesKill blood parasitesTx has changed. Artemisinin are DOC
39Treatment Chloroquine-sensitive P.vivax P.ovale P. malariae Chloroquine 10mg base/kg (max 600mg base)Followed by 5mg/kg base (max 300mg base)At 6, 24,and 48 hoursCure rates 95%Chloroquine resistantP. vivaxMefloquine or quinine PLUS doxycyclinePrevention of relapseLiver forms of malariaP. vivax and P. ovalePrimaquine 30mg/day for 14 daysStart immediately after completing chloroquineScreen for glucose-6-phosphate-dehydrogenase to prevent hemolysis
40P. Falciparum malaria Chloroquine-sensitive Treat like other forms of malaria for the chloroquineMost cases are chloroquine-resistantUncomplicated diseaseOne of the following:Quinine-basedAtovaquone-proquanilMefloquineArtemisinin derivative combinationsQuinine sulfate 10mg/kg salt (max 650 mg) q8hrs for 3-7daysCombined with3 tabs of pyrmethamine-sulfadoxine(25/500mg) on day threeOr doxycycline 100mg po bid for seven daysQuinine causes reversible tinnitus and reversible high-tone hearing loss
41P. Falciparum malaria Atovaquone-proquanil 250mg atovaquone plus 100mg proguanilFour tablets for 3 daysCommon side-effects gastrointestinalMefloquine25 mg/kg base as a single doseSide-effectsVomiting,nightmares,ataxia,delirium,seizuresArtemisinin derivativesIV ,IM or oralGiven for 5-7 days4mg/kg on day 12mg/kg on days 2,31mg/kg on days 4-7Combined withMefloquine-750mg then in 12 hrs 500mgOr doxycycline 100mg po bid for 7 daysNo serious toxicities from artenisinin derivatives have been observed in humans
43Treatment-severe disease Use intravenous medicationsQuinine-basedIV quinidine gluconate 10mg/kg over 2 hrs the 0.02mg/kg/minArtemisinin-basedArtesunate 2.4 mg/kg IV followed by 1.2mg/kg at 12 and 24 hrs the 1.2mg/kg daily for 6 daysQuinine-resistantArtenisinin-basedPlus tetracycline or mefloquineArtenisinin not in the United statesNeed to use quinine plus tetracycline/doxycyclineSupportive measuresExchange transfusionFor parasitemia > 10%Or MSOFTransfusionRemoves parasitized red blood cellsParasitic toxinsCytokinesReplaces with fresh plasmaContinue until parasitemia < 5 %
44Prognosis Mortality Untreated-100% Treated -10-40 % Indicators of poor prognosisAge < 3 yearsDeep comaConvulsionsPapilledemaAbsent corneal reflexes,decorticate/decerebrate rigidityOrgan dysfunction,ARDS,shockParasitemia > 5%Peripheral mature pigmented parasitesHematocrit <15 %, hemoglobin < 5 g/dLPeripheral WBC > 12,000Blood glucose < 40 g/dLBUN > 60 mg/dL or creatinine > 3mg/dLLactate > 5 mmol/LIncreased liver function test 3 times normalHigh CSF lactate >6 mmol/LLow antithrombin III levelsHigh plasma TNF concentrationMalaria – know it is prevetable. Travelers with a fever need to RO malaria.
45Rocky Mountain Spotted Fever Causative agent rickettsiaGram-negative bacteria-coccobacillusIntracellular parasiteGrows in the nucleus and cytoplasm of host cellsVectorDermacentor variabilis-American dog tickEastern and south central United StatesDermacentor andersonii-Rocky Mountain wood tickMountain states west of MississippiBrown dog tick (Rhipicephalus sanguineus)ArizonaRicksettsiaInduces cell death and necrosisLeads to vasculitisHemorrhageIncreased vascular permeabilityEdemaActivation of humoral immunityMostly in maryland
49Clinical manifestations Occurs in spring and summerFever-commonSevere headacheMalaiseArthralgiasNauseaBetween 3-5 daysRashBegins on the ankles and wristsSpreads to hands and feetSpreads centrallyMaculopapular and becomes petechialAbnormal mentationSeizuresFocal neurologic deficitsSpreads peripherally to central
54Treatment Orally or IV Doxycycline 100mg bid Continued for at least three days after patient afebrileUsual length5-7 days
55Outcome Severe RMSF sequelae Peripheral neuropathy Hemiparesis DeafnessMortality< 4 years3-4 %> 60 years4-9 %Host factors associated with severe diseaseMale genderBlack raceChronic alcohol abuseGlucose-6-phosphate dehydrogenase deficiencyCan be severe and still causes deaths in people that have other issues.
56Tularemia Caused by a gram-negative coccobacilli Francisella tularensisPredominantly in the Northern hemisphereCan persist in water,mud or animal carcasses for weeksReplicates in macrophages/leukocytesNatural infections found inTicks,mosquitoes,horse flies,fleas,liceHuman infectionsVectors (ticks,biting flies,mosquito)Handling of infected animals (cleaning rabbits)Undercooked meatDrinking contaminated waterCat scratches or bitesSplashing infected material in the eye
58Clinical manifestations Abrupt onsetFeverChillsHeadacheMalaiseIncubation period 2-10 daysSix clinical syndromesUlceroglandularGlandularThyphoidalPneumoniaOropharyngealOculoglandularMostly causes ulcer, dis in lungs and lymph nodes.Someone with ulcerative disease, and get fevers.
59Syndromes Ulceroglandular Single erythematous papuloulcerative lesion Central escharTender regional lymph nodesGlandularEnlargement of single of multiple lymph nodesTyphoidalFebrile septic illnessLack of exposure historyPneumonicPulmonary infectionAirborne or hematogenous spreadUnilateral of bilateral infiltratesInfiltrates are nodularHilar adenopathy,pleural effusionsOropharyngealIngestion of poorly cooked meatSevere painful pharyngitisCervical lymphadenopathyOculoglandularConjunctival erythemaPeriorbital edema
63Tularemia Diagnosis Serologic Tube agglutination ELISA PCR Treatment Streptomycin-drug of choice10mg/kg IM q 12hrs for 7-10 daysRecommended for meningitisSevere diseaseOther optionsGentamicin : 3-5mg/kg IM/IV q8hrs for 7-10daysTetracycline: 500mg po qid for 14 daysDoxycycline : 100mg po bid for 14 daysChloramphenicol : 25-60mg/kg per day in 4 doses for 14 daysMortality 2-4 percentComplicationsDrainage of lymph nodesPericarditisMeningitisARDSRhabdomyolysis/renal failure