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MedicineBoardsCertificationReview

InfectiousDiseases, Part2LisaG.Winston,MDUniversityofCalifornia,SanFranciscoDivisionofHIV,ID,andGlobalMedicineandDivisionofHospitalMedicineZuckerberg SanFranciscoGeneralHospitalandTraumaCenter

Case#1

32y/oMwith3daysofanenlarging,painfullesiononhisLthighthatheattributestoa“spiderbite”

T36.9BP118/70P82

Howwould youmanagethispatient?

A. Incision anddrainage

B. Dicloxacillin 500mg4x/day

C. TMP-SMXDS1tabtwicedaily

D. Cephalexin 500mg4x/day

Abscesses: I&Dplusantibioticvs.I&DaloneTMP-SMX

TMP-SMXTMP-SMX

p =0.25 p = NS p = 0.12 p = 0.005

RajendranAAC2007;DuongAnnEmerg med2009;SchmitzAnnEmergMed2010;TalanNEJM2016

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Abscesses: I&Dplusantibioticvs.I&Dalone

• Benefits toantibiotics– Slightlyhighercurerates– Decreaseinnewskininfections(short-term)– Talan2016studyalsoshowedlowerratesubsequentsurgicaldrainageanddecreasedinfectionsinhouseholdmembers

Antibiotic therapyrecommended forabscessesassociated with:

• Severedisease

• Signsorsymptomsofsystemicillness

• Immunosuppression

• Extremes ofage

• Difficult todrain area(face, hand, genitalia)

• Failureofprior I&D

Liu C. Clin Infect Dis. 2011

MicrobiologyofPurulentSSTIs

Moran NEJM 2006

OralantibiotictreatmentforpurulentSSTI

Drug AdultDose

TMP/SMX DS 1-2tab twice daily

Doxycycline, Minocycline 100mgtwicedaily

Clindamycin 300-450mg3x/day

Linezolid 600 mgtwicedaily*Rifampin is NOT recommended for routine treatment of SSTIs

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Case#2

28y/owomanpresentswitherythemaofherleftfootoverpast48hrs

Nopurulentdrainage,exudate,orfluctuance.

T37.0BP132/70P78

Howwouldyoumanagethispatient?

A. Watchcloselyfor self-resolution

B. Cephalexin 500mg4x/day

C. Cephalexin 500mg4x/dayplusTMP-SMX1DStwice daily

D. Admit forIVvancomycinwith rapidtransitiontooralantibiotics whenimproved

Cephalexin vs.Cephalexin +TMP-SMXinpatients with Uncomplicated Cellulitis

Pallin CID2013; 56:1754-1762

N=146

Clindamycin vs.TMP-SMXforuncomplicated skininfections

p = 0.38p = 1.00

n = 160 n = 280

MillerNEJM2015

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Treatment ofuncomplicatednon-purulentcellulitis

Drug AdultDose

Cephalexin 500mg 4x/day

Dicloxacillin 500mg 4x/day

Clindamycin* 300-450mg 3x/day

TMP-SMX*(new) 1-2 DStwicedaily

Linezolid* 600mg2x/day*Activity against MRSA

Empiricaltreatmentofcomplicatedskin andsoft tissueinfections

• Admitted tofloor with abscessorcellulitis– I&Dabscess– Vancomycinoralternativeantibiotic(considercefazolinforcellulitis)• Alternative:daptomycin,linezolid,tedizolid,dalbavancin,oritavancin,telavancin,ceftaroline

– NoneedforGramnegativecoverage• Patient admitted toICU/necrotizing fasciitis

– Vancomycinoralternative+Gramnegativecoverage+clindamycin

Case#3:

An85year-oldwomanisadmittedtothehospitalwithaCHFexacerbation.Otherco-morbidconditionsincludediabetesandchronickidneydisease(creatinine=2.5mg/dL).Aurinalysisshows10– 20WBC/HPF.Aurinecultureissentandgrowspan-sensitiveE.coli>100,000cfu/mL.Thepatientdeniesspecificurinarysymptoms.

Whichisthebestcourseofaction?

Case#3:

A. Ciprofloxacin for3daysB. Ciprofloxacin for10daysC. Trimethoprim-sulfamethaxazole for3daysD. Fosfomycinfor1dayE. Nitrofurantoin for7daysF. Noantibiotics

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UrinaryTractInfections

• Uncomplicated cystitis• Women,pre-menopausal,non-pregnant,nourologicabnormalities

• Escherichiacoli70-90%• >35%ampicillinresistance• >20%trimethoprim/sulfamethoxazoleresistanceinmanyareas

• Nitrofurantoin(5days)isgenerallyreliable• IDSAguidelinesrecommendavoidingfluoroquinolones

Guptaetal.Clin InfectDis2011;52(5):e103-120

UrinaryTractInfections

• Recurrent cystitis inwomen (>3x/year)– Dailyor3xweeklyprophylaxis– Post-coitalprophylaxis– Self-treatment forsymptoms

• Selfdiagnosisaccurate– Othermeasures

• Discontinuediaphragmand/orspermicide• Topicalestradiolinpost-menopausalwomen• ?Cranberryjuice

UrinaryTractInfections

• Pyelonephritis– Obtainurineculture– Outpatientinitialrx:fluoroquinolone– Hospitalize

• Inadequatep.o.intake• Severedisease/underlyingillness• Pregnancy

– Initialrxinhospital:fluoroquinolone;aminoglycoside;extended-spectrumcephalosporin(ceftriaxone);extended-spectrumpenicillin;carbapenem• MayswitchtoTNP-SMXifsusceptible

UrinaryTractInfections

• Imaging(U.S.orCT)• Notbetterin72hours• Multipleepisodes• Lowerthresholdinmen

• Tip:remember not tousemoxifloxacin forUTIs

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Case#4:60y.o.womanwithHTNpresentswith3daysofcough

withgreensputum,dyspneaonexertion,fever,pleuriticchestpain.Sheotherwisehasnopastmedicalhistory.

Exam:• 38.5º145/901001895%RA• Chest:cracklesatleftbaseData: WBC:15,500CXR:LLLinfiltrate

• Whatisthemostappropriate treatment?

Case#4:

A. Oralantibioticsathome

B. HospitalizeforIVantibioticsinitially;whenafebrile, switchtooralantibioticsanddischargehome

C. HospitalizeforIVantibioticsinitially;whenafebrile, switchtooralantibioticsanddischargeafter24hoursobservation

D. Hospitalizeforminimumof7daysofIVantibiotics

Pneumonia SeverityIndex

DemographicAge (+1point/yr, -10ifwoman)Nursing home (+10)

ComorbiditiesCancer (+30)Liverdisease (+20)CHF (+10)Cerebrovascular dz (+10)Renal disease (+10)

ExaminationMental status (+20)Pulse >125 (+20)Resp rate>30 (+20)SBP<90 (+15)Temp <35or>40 (+10)

LabspH<7.35 (+30)BUN>30 (+20)Na<130 (+20)Glucose >250 (+10)p02<60 (+10)Hct <30 (+10)Pleural effusion (+10)

Don’t memorize this!

Pneumonia SeverityIndex

Class PSI score Mortality Triage

I Age < 50, no comorbidity, stable vital signs

0.1% outpatient

II ≤ 70 0.7% outpatient

III 71-90 3% consider admission

IV 91-130 8% admission

V > 130 29% ? ICU

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Admissionforcommunity-acquiredpneumonia?

Outpatient:– Younger– Nocancerorend-organdisease

– Noseverevitalsignabnormalities

– Noseverelaboratoryabnormalities

Inpatient:– Doesn’tmeetoutpatienttreatmentcriteria

– Hypoxia– Activecoexistingcondition– Unabletotakeoralmeds– Psychosocialissues

CAP:WhentoDischarge

• Safetodischargewhenafebrile,hemodynamicallystable,nothypoxic,andtoleratingPO

• NominimumdurationofIVtherapyneeded• Noneedtowatchin-hospitalonoralantibiotics• FormostpatientswithCAP,7totaldaysof

antibiotictreatmentisadequate

Case#5:

82y.o.man presentswith5daysofproductive coughand dyspnea. Hispastmedical historyisnotable forCOPD. Denies recenttravelorhospitalization.Exam:

• 39º110/901102485%RA• Chest:cracklesatrightbase

Data:• CXR: Rightlower&middlelobeinfiltrates• Labs: WBC12,000,BUN=38,otherwisenormal

Whatisthemost appropriate treatment?

Case#5:

A. Cefuroxime IVB. Levofloxacin IVC. Piperacillin /tazobactam (Zosyn)IV+

vancomycinIVD. Cefepime IV+tobramycin IV

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EtiologyofCAP

• Clinical syndromeandCXR not predictive oforganism– Streptococcuspneumoniae– Haemophilusinfluenzae– Mycoplasmapneumoniae– Chlamydophilapneumoniae– Legionella– (EntericGramnegativerods)

– Viruses– Staphylococcusaureus(many)

Covered byusual regimes

Not covered byusual regimens

EmpiricalTreatmentforOutpatients

No comorbidity or recent antibiotics

• Macrolide or• Doxycycline

Comorbid condition(s) (age > 65, EtOH, CHF, severe liver or renal disease, cancer, etc.)

orAntibiotics in last 3 months

§ b-lactam (e.g. amoxicillin) + either macrolide or doxycycline

or• Respiratory

fluoroquinolone* * NOT Ciprofloxacin

EmpiricalTreatmentforInpatientsInpatientnon-ICU

§ b-lactam + either macrolide or doxycycline

or• Respiratory fluoroquinolone

Inpatient ICU § b-lactam + either azithromycin or respiratory fluoroquinolone(Penicillin allergy: fluoroquinolone + aztreonam)

Healthcare associated pneumonia

• Antipseudomonal b-lactam or carbepenem + either fluoroquinolone or aminoglycoside

(Controversial and still being revised)

MRSA concern • Add vancomycin or linezolid to above

DiagnosticTestinginCAP• Chestradiography:

– Indicatedforallpatientswithsuspectedpneumonia– Cannotdistinguishatypicalvs.typicalpathogen

• Bloodculture:– Recommendedforsomeinpatients,basedon

severityofillness(beforeantibiotics)• Sputumexam:

– Recommendedforsomeinpatients– Mosthelpfulifsingleorganisminlargenumbers

• Moleculartestingincreasinglyavailable

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Pneumonia:OtherDiagnostics• ConsiderLegionellatestinginsickerpatients

usingrespiratorycultureorurineantigen• Influenzatestingduringinfluenzaseason–

usesensitivetest• Parapneumoniceffusions:

– Small,free-flowingeffusionsdon’tneedtobetapped

– Tapifloculatedorifpatientnotimproving

Case#6A67-year-oldmanwasbroughttotheEDbyparamedicsbecauseofdifficultybreathingandincreasedcoughandconfusion.Thepatienthadcomplainedofcoughwithyellowsputuminthepastthreedaysandincreasingdyspnea.

CXR:Rightlowerlobarinfiltrateandmoderatepleuraleffusion.

Sputum:Manypolymorphonuclearneutrophilsandmanygram-positivecocciinpairsandchains.

Case#6: Case#6

Thepatientwasadmittedandstartedonceftriaxoneandazithromycin.Histemperaturedecreasedto38˚Cafter48hoursandhefeltsomewhatimproved.

Onhospitalday#3,hedevelopedanincreasedtemperature to39˚Candwastachypneicat35breaths/minutewithanoxygensaturationof88%onroomair.Thepatientbecamemoreconfusedandwastransferredtotheintensivecareunit.

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Case#6

Whichof thefollowingshouldbe donenow?A.ChangeantibioticstolevofloxacinB.ChangeintravenouslinesandaddtobramycinC.PerformadiagnosticthoracentesisD.Administerstressdosesofcorticosteroids

ClinicalSyndromesPneumonia gonebad

Whenpneumonia failstorespond toinitialtreatment or getsworse, consider

– Wrongbug– Wrongdrug– Noninfectiousetiology– Complicationsofpneumonia,e.g.empyema– Naturalhistoryofdisease

Pneumococcal Vaccines: - polysaccharide vaccine(PPV23)- Pneumovax- proteinconjugatevaccine(PCV13)- Prevnar

Conditions PCV13 PPV23 PPV23#2

Age ≥ 65years Yes Yes No

Age 19-64withchronicheartorlungdisease(includingasthma),smokers

No Yes No

CSF leakorcochlearimplant Yes Yes No

Functional/acquiredasplenia Yes Yes Yes

Immunocompromised Yes Yes Yes

Case#7:• A70year-oldmanishospitalizedfordiverticulitis.

Heisnearingdischargewhenhedevelopsanewfever. Purulentdrainageisnotedfromacentralvenouscatheter,anditisremoved.Despiteremovalofthecatheter,feverpersistsforseveraldays.Physicalexaminationrevealsanewsystolicmurmur.Echocardiogramshowsasmallvegetationonthemitralvalve.

• WhichorganismMOSTLIKELYgrewfromhisbloodcultures?

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Case#7:

A. StaphylococcusaureusB. StreptococcusbovisC. EnterococcusD. Candida

Endocarditis

• Mostcommon organisms– Staphylococcusaureus (especiallyhealthcare-associated,injectiondruguse)

– Streptococci,viridansgroup;alsoS.bovis– Coagulase-negativestaphylococci(especiallyprostheticvalve)

– Candida– Culturenegative– HACEK

Endocarditis

• Diagnosis: Modified DukeCriteria– Major

• Specificmicrobiologic– usuallybloodcultures• Evidenceendocardialinvolvement

–Newvalvularregurgitation–Specificechocardiographicfindings

– MinorPredisposition VascularphenomenaFever ImmunologicphenomenaOthermicrobiologic

Osler nodes Janeway lesions

Splinter hemorrhages

Roth spots(white-centered

retinal hemorrhages -arrow heads)

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Endocarditis

• Dukecriteriacontinued…– Definiteendocarditis=2major;1major+3minor;5minor;orpathologicallyconfirmed

– Possibleendocarditis=1major+1minor;3minor

• Surgery indications:CHF,continuedsystemicemboli,uncontrolledsepsis,abscess,fungalIE;oftenprostheticvalve,Gramnegativeaerobesandunusualorganisms

Endocarditis - Treatment

• Penicillin-susceptiblestreptococcus– PenicillinGorceftriaxonex4wk– PenicillinGorceftriaxone+gentamicinx2wk

• StreptococcusMIC>.1to.5µg/mL– PenicillinGorceftriaxonex4wk+gentamicinx2wk

• Penicillin-susceptibleenterococcus– AmpicillinorpenicillinG+gentamicinx4-6wk– Ampicillin+ceftriaxonex6wk

Use recommended regimens!

Endocarditis - Treatment

• NativevalveMSSA– Nafcillinoroxacillinorcefazolinx6wk

• NativevalveMRSA– Vancomycinx6wk– Daptomycinx6wk

• HACEK– Ceftriaxonex4wk– Ampicillinx4wk(ifsusceptible)

Baddour Circulation2015

Endocarditis - Prophylaxis

• CurrentguidelinesfromAmericanHeartAssociation2007

• Verydifferentfrompreviousguidelinesupdatedin1997

• Prophylaxisonlyforpatientswithhighestriskforadverseoutcomes:– Prostheticvalve,previousendocarditis,cardiactransplantationwithvalvulopathy,certaincongenitalheartdisease

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Endocarditis - Prophylaxis

• Forcardiacconditionsonpreviousslideonly,prophylaxisfordentalprocedureswithmanipulationofgingivaorperiapicalregionofteethorperforationoforalmucosa

• NoprophylaxisGIorGUproceduresforpurposeofpreventingendocarditis

WilsonCirculation2007

Case#8:

• A40year-oldwoman whoreturned 2daysagoaftera3-weektriptoeastAfrica presentswithfever. Shehad beenprescribed mefloquine (Lariam) formalariaprophylaxis butstopped takingitduetoinsomnia. Shedeveloped feverduring theflighthome. Other symptoms include chills, diaphoresis,myalgia,andheadache. Shehas hadno diarrhea.Activitiesincluded frequent hikes,andshe swaminfreshwater1weekbeforeherdeparture.

• YouareconcernedaboutallofthefollowingEXCEPT

Case#8:

A. MalariaB. TyphoidC. Rickettsial infectionD. Acuteschistosomiasis (Katayamafever)

TravelMedicine

• Returned travelerwith afever– Shortincubationperiod(<14days):

• Malaria(especiallyfalciparum)• Dengue• Chikungunya• Zika• Typhoidfever

–Also,non-tropicaldiseases– Incubationperiod>14days

• Malaria:falciparum(~1month)andnon-falciparum• Typhoidfever(3weeks;rarelyupto60days)• Hepatitis,especiallyAandE

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TravelMedicine

• Workupforfever–Right away

• Malaria smears• Bloodcultures(typhoid,meningococcus)• Other,directedappropriateevaluation:e.g.CXRforrespiratorysymptoms

TravelMedicine

• Other teststoconsider– Eosinophilcount– Stoolstudies(diarrheaorelevatedeosinophils)– PCR(dengue,chikungunya,Zika)– Serologies(hepatitis,dengue,chikungunya,Zika,leptospirosis,helminthicinfections)

– HIV– Occasionally,bloodsmearsand/orskinsnips(microfilariae)

TravelMedicine

• Initial therapy– Ideally,etiologydirected– Supportive– Ifvery ill,antibiotics(e.g.ceftriaxone,fluoroquinolone)pendingdiagnosis

– Considerempiricaltherapyifcharacteristicsyndrome• Rickettsialdisease• Leptospirosis

TravelMedicine• Immunizations

– HepatitisA,typhoid– Ifnotup-to-date:tetanus-diphtheria(+/- pertussis),measles

– Dependingondestinationandactivities:hepatitisB,Japaneseencephalitis,yellowfever,polio,meningococcus,rabies

• Diarrhea:– Loperamidetotreatifnon-inflammatory– Considerbismuthsubsalicylateprophylaxis– Okaytogivefluoroquinoloneifsymptomsdevelop

• Alternatives:azithromycinorrifaximin

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Case#9:

• A60year-oldmanwithahistoryofmultiplemyelomaisbroughtinbyhisfamilytotheEmergencyDepartment. Hisfamilyreports1dayofheadache,fever,andconfusion.Thepatientislethargicandunabletoanswerquestions.LumbarpuncturerevealsaWBCcountof800cells/µL,glucose30mg/dL,andprotein150mg/dL.GramstainshowsmanyWBC,noorganisms.

• Whichoneofthefollowinginitialregimensisappropriate?

Case#9:

A. Ceftriaxone, vancomycin,ampicillin, anddexamethasone

B. Ceftriaxone, vancomycin,anddexamethasone

C. Ceftriaxone andvancomycinD. Ceftriaxone, vancomycin,and ciprofloxacin

BacterialMeningitis

• Very serious disease– Morbidityandmortalityremainhigh– Fatalwithoutantibiotics– emphasisonrapiddelivery

– SteroidsindicatedinadultsgivenbenefitforStreptococcuspneumoniae;givebefore—oratleastwith—firstdoseantibiotics

deGans NEJM2002

BacterialMeningitis

• Organisms– Neonates:S.agalactiae,E.coli,L.monocytogenes– Children:N.meningitidis,S.pneumoniae,(H.influenzae)

– Youngeradults(healthy):S.pneumoniae,N.meningitidis

– Olderadults(underlyingdisease):S.pneumoniae,L.monocytogenes

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BacterialMeningitis

• General indications for CTbefore LPwhenmeningitis suspected– Age(>60years)– Immunocompromise– HistoryofCNSdisease(e.g.masslesion)– Recentseizure– Neurologicabnormalities

• Includingfocaldeficitandabnormallevelofconsciousness

– Papilledema

BacterialMeningitis

• Empirical antibiotic therapy– Youngeradults:broad-spectrumcephalosporin(highdose),oftenplusvancomycin– whenatleastmoderatesuspicionpneumococcus

– Olderadults/underlyingillness:asabove+ampicillinortmp/smx(penicillinallergy)

• ProphylaxisforclosecontactsonlyifN.meningitidisandsomecasesH.influenzae

Encephalitis

• Herpessimplexencephalitis– Mostcommontreatableencephalitis– Lowthresholdtoaddacyclovir

• WestNileVirus:3formsneuroinvasive– ageisbiggestriskfactor– Meningitis– favorableoutcome– Encephalitis– alteredlevelofconsciousnessand/orpersonalitychange+CNSinflammation

– Acuteflaccidparalysis– worst

Case#10• An85year-oldwomanisadmittedinJanuarywithfeverandshortnessofbreathfor36hours.Sheliveswithherdaughterandgrandchildren.CXRshowsapatchylowerlobeconsolidation.Sheisintubatedforrespiratorydistressandhypoxemia.TrachealaspirateGramstainshowsPMNsbutnoorganisms.ArapidantigentestisnegativeforinfluenzaAandB.

• Whichmedicationswouldyoustart?

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Case#10:

A. Levofloxacin +azithromycinB. Metronidazole +azithromycinC. Vancomycin +ceftriaxone +rimantidineD. Vancomycin +piperacillin/tazobactamE. Ceftriaxone +azithromycin +oseltamivir

Influenza

• Twotypesofclinical importance: AandB• InfluenzaA

– Infectsanimals;causeofpandemicinfluenza– Previouslywassusceptibletoadamantanesandneuraminidaseinhibitors• Circulatingstrainsresistanttoadamantanes

– Typedbysurfaceglycoproteinshemagglutininandneuraminidase

• Influenza B– notsusceptible toadamantanes

Influenza

• Neuraminidase inhibitors - block cleavagefromhost cellsurface– Oseltamivir– oral– Zanamivir– inhaled– Peramivir– IV

Influenza

• Insusceptible influenza, alldrugsreduceclinical illnessbyabout 1daywhen startedwithin 48hrs.ofsymptoms– Likelyefficaciousforprophylaxis

• Observational datashowmortality benefit forhospitalized patients treated with oseltamivir,evenoutside 48hr.window

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Influenza

• Influenzavaccine recommended foreveryone>6months ofage,unless there isacontraindication (rare)– Starting2016-17,eggallergynolongeracontraindication

InfectionControl

Type of Precaution

Conditions Examples

Contact DiarrheaWoundsVesicular rashesSome resp infections

C. difficile, chickenpox, smallpox, scabies, lice, viral conjunctivitis, drug resistant organisms

Droplet MeningitisSome resp infections

Meningococcus, pertussis

Airborne Some resp infections TB, chickenpox, measles, smallpox, SARS

Case#11:

• A35year-oldmanwhorecentlyreturnedfromHawaii(thebigisland)complainsoffever,myalgia,andheadache.Conjunctivalsuffusionisnoted.Hereportsthatheswaminafreshwaterpond,althoughtherewasasignpostedthatswimmingwasnotadvisable.Hewondersifthiscouldhaveanythingtodowithhiscurrentillness.

• Whattherapyisnowappropriate?

Case#11:

A. CephalexinB. ChloramphenicolC. PenicillinD. Gentamicin

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Potpourri

• Leptospirosis– Biphasicillness(renal/hepaticinvolvementsecondphase)– Jarisch-Herxheimerreactionpossible

• Lymedisease– Borreliabergdorferi spreadbydeertick(nymphal)– Prolongedattachment(48-72hrs)– Clinicaldiagnosis:erythemamigrans– PEPwithdoxycyclineiseffectivebutonlyindicatedifsubstantialrisk

– ProlongedIVtherapyforchronicsxsineffective

Potpourri

• Other Borrelia– Tick-bornerelapsingfever

• BorreliahermsiithoughttobemostcommoncauseinU.S.

– Outdoorexposure,westernU.S.• Linkedtosleepinginrusticcabins

– Examinebloodsmearduringfeverforspirochetes– Treatwithdoxycycline(Jarisch-Herxheimerrxncommon)

Potpourri

• RecognizeRockyMountainspottedfever• Transmittedbyticks(mostlyDermacentor– dogandwoodticks);latespringandsummer– EspeciallySouthAtlanticandEastSouthCentralstates

• AgentisRickettsiarickettsii• Classicpetechialrashnotinallpatients,notalwaysonpalmsandsoles– Maynotappearuntil3-5daysafterfever

• Treatwithdoxycycline– lowthreshold• Diagnosisusuallyconfirmedretrospectivelywithserology

Potpourri• EhrlichiosisandAnaplasmosis

– EhrlichiachaffeensisandE.ewingiitransmittedbylonestartickinsoutheasternandsouthcentralU.S.• Mayseerash

– AnaplasmaphagocytophilumtransmittedbyIxodes (deer)tickinuppermidwest,northeast,northernCA• Morelikelytoseemorulae(inclusions)• Rashuncommon

– Fever,headache,myalgia;leukopenia,thrombocytopenia,elevatedAST/ALT

– Diagnosedbasedonantibodytiters– Treatwithdoxycycline

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Potpourri

• Differential diagnosis ofnodularlymphangitis– Sporothrixschenckii– Mycobacteriummarinum– Nocardiabrasiliensis– Othermycobacteriaandotherorganisms(rarely)

– Don’tforget:GroupAstreptococcus,especiallyifmoreacute;S.aureus

Potpourri

• Erysipelothrix– Grampositiverod– “Fishhandler’sdisease”– Treatwithpenicillin(manyotherantibiotics)

• Vibrio vulnificus– Sepsisandcutaneouslesionsinimmunocompromisedhost(esp.cirrhosis)aftereatingoysters

– Cellulitisafterexposuretoseawater– Antibioticsmayincludeceftazidime,doxycycline,ciprofloxacin

Potpourri

• Anthrax– Severe illness– Widenedmediastinum,meningitis,earlypositivebloodcultures

– UlcerafteranimalcontactorBTscenario

Potpourri

• Tularemia– Ticks/bitingflies;animalcontact(e.g.skinning);airbornetransmission

– Rabbitsandothersmallmammalsarereservoir– Presentationoftendependsonmodeoftransmission:e.g.glandular/ulceroglandularfromtickbite,pneumonicfrombrushcutting,alsotyphoidalform

– Notifylabifsupected– canbetransmittedfromculture– Rx:streptomycin(preferred),gentamicinalternate;fluoroquinolonesactive;tetracyclinescanbeusedwithmilderillness• Chloramphenicolusedformeningitis– maybedifficulttoobtaininU.S.

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Potpourri

• Babesia– Tick-borne,intraerythrocyticprotozoa– Symptomaticwithsplenectomy,immunecompromise,olderage

– Canbeco-transmittedwithLyme– “Maltesecross”(tetrads)– Treatment withatovaquone+azithromycinorquinine+clindamycin

Miscellaneous Tips:

• Withuncommondiseases,classicpresentation• Considerdoxycyclinedeficiency• Chloramphenicol:notlikelytheanswer• Reviewtick-borneillnesses• Reviewsyphilis• Typically,limitedHIV• Nothingcontroversialorbrandnew