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Infectious Diseases for the Medicine Boards

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Title: Infectious Diseases for the Medicine Boards


1
Infectious Diseases for the Medicine Boards
  • Christopher Hurt, MD
  • Division of Infectious Diseases
  • June 2010

2
What is sure to be on the boards
ABIM Exam Blueprint, http//www.abim.org/pdf/bluep
rint/im_cert.pdf
3
What may be on the boards
ABIM Exam Blueprint, http//www.abim.org/pdf/bluep
rint/im_cert.pdf
4
What wont be on the boards
  • Dosages of antimicrobials
  • Emerging pathogens
  • 2009 H1N1 unlikely, but oseltamivir-resistant flu
    A could be
  • Topics that are controversial or which have no
    consensus guideline, such as
  • Treatment of multidrug-resistant TB or HIV
  • Probably wont ask you for second- or third-line
    antimicrobial selections
  • (thats special torture reserved for ID boards)
  • Bioterrorism
  • (at least recognize wide mediastinum of
    inhalation anthrax)

5
Lets go!
6
Critical care ID - 1
  • SIRS 2 or more of fever or hypotherm
    tachycardia tachypnea/hypocarbia leukocytosis
    or leukopenia
  • NOT necessarily due to an infection
  • Sepsis SIRS plus micro-confirmed or observable
    infxn
  • Severe sepsis sepsis plus at least one sign of
    organ hypoperfusion
  • Mottled skin, delayed cap refill, decr UOP,
    lactatemia, AMS, abnl EEG, thrombocyto, DIC,
    ALI/ARDS, cardiac dysfunction
  • Septic shock severe sepsis plus low MAP and/or
    pressor requirement

7
Critical care ID - 2
  • Drotrecogin alpha (Xigris)
  • PROWESS 96h infusion w/in 24h of presenting
  • 28d mortality rate lower with drotrecogin
  • Increased bleeding with drotrecogin
  • Post-hoc analysis of greatest benefit to most
    severely ill, with APACHE II scores 25 or MSOF
  • Lower incidence of MSOF among treated patients,
    and they also had more rapid recovery of
    cardiopulm function

8
Critical care ID - 3
  • Who should NOT get drotrecogin alpha (Xigris)
  • Preggers or breast-feeding
  • Severe thrombocytopenia (lt30K)
  • ANY invasive procedure within 12h of starting
    drug
  • Spinal epidural anaesthesia is a favorite trivia
    bit
  • Head trauma, intracranial surg, or CVA w/in 3mos
  • Known hypercoagulable condition
  • Patient not expected to live 28d post-infusion
  • Acute pancreatitis with no identified source of
    infxn

9
Critical care ID - 4
  • Lines and bloodstream infections (BSIs)
  • Yank all intravascular catheters as soon as
    feasible
  • Dirtiness femoral gt IJ (drool!) gt SCL
  • If the line is okay, leave the damn thing alone
    no evidence that scheduled (q3-5d) line changes
    help reduce nosocomial BSIs
  • For site prep, use chlorhexidine gluconate (CHG)
    over povidone/iodine (Betadine), if given a choice

10
CNS Infections - 1
  • Meningitis pain, headache, lethargy, function
    OK
  • Aseptic (viral or non-infectious) or bacterial
  • Encephalitis brain abnormalities
  • Hemiparesis, AMS, flaccid paralysis,
    paraesthesias
  • Distinctions usu based on CSF viral dzs have
    lower WBC counts, only modest protein elev,
    near-normal glucose
  • Dont hang your hat on lymphs vs PMNs to help!
    You can see lymphs in early or partially txd
    bacterial meningitis
  • Meningoencephalitis elements of both syndromes

11
CNS Infections - 2
  • Encephalitis
  • Viral neuronal involvement by MRI
  • Measles, VZV, CMV, influenza, arboviruses
  • HSV-1 is responsible for most deaths in
    encephalitis
  • West Nile is like polio or Guillain-Barré
    flaccid ascending paralysis
  • Post-infectious aka acute dissem.
    encephalomyelitis (ADEM) neuronal sparing,
    perivascular inflamm w/ demyelination (often an
    incidentaloma on MRI)

12
CNS Infections - 3
  • Meningitis Viral and Noninfectious
  • Viral enteroviruses, HSV, HIV, WNV, VZV, mumps
  • PCR is diagnostic tool, esp for entero and
    HSV/VZV
  • Acute HIV can present with mono-like illness
    meningitis
  • HSV more likely culprit if pt presenting with 1
    genital lesion
  • Recurrent HSV-2 associated meningitis episodes
    Mollarets
  • Other bugs RMSF (Rickettsia), Ehrlichia, Lyme
    (Borrelia)
  • Non-infectious causes
  • Malignancy (breast, lung, melanoma, GI, unk
    primaries)
  • Drug-induced (NSAIDs, TMP/SMX, IVIG, OKT3
    immsupp)

13
CNS Infections - 4
  • Meningitis Bacterial
  • Access CNS either through contiguous spread
    (e.g., parameningeal focus, sinus/middle ear) or
    hematogenous
  • Bugs in adult bacterial meningitis (up to age 60)
  • Streptococcus pneumoniae 60
  • Neisseria meningitidis 20
  • Haemophilus influenzae 10
  • Listeria monocytogenes 6
  • Group B Streptococcus (agalactiae) 4
  • Over age 60, 70 S.pneumo and 20 Listeria

14
CNS Infections - 5
  • Meningitis Bacterial
  • Listeriosis has more seizures and focal neuro
    deficits, presenting as rhomboencephalitis
    (ataxia, CN palsies, nystagmus) think this in
    an elderly meningitis vignette
  • Gram stain buzzwords
  • Gram-positive, lancet-shaped diplococci
    S.pneumo
  • Gram-negative diplococci N.meningitidis
    (meningococcus)
  • Gram-negative coccobacilli H.flu
  • Gram-positive rods or coccobacilli Listeria

15
CNS Infections - 6
  • Meningitis Bacterial TREATMENT
  • DO NOT DELAY if the Q frames pt languishing in
    ER for hours before you see him, give abx before
    doing the LP
  • Look for papilledema in lieu of getting a head CT
  • If ß-lactam is an option, use it cidal,
    penetrates the BBB
  • Empirical therapy hi-dose ceftriaxone
    vancomycin
  • Ceftriax 2gm q12 meningococcus PCN-sensitive
    S.pneumo
  • Vancomycin PCN-resistant S.pneumo
  • IF OVER AGE 50, add ampicillin (gent) for
    Listeria
  • Only scenario for adjunctive dexamethasone is
    highly suspected (or confirmed) pneumococcal
    meningitis

16
CNS Infections - 7
  • Rhinocerebral zygomycosis not mucormycosis
  • Hyperglycemic diabetic patient in HHS/HONK or DKA
  • Acute sinusitis with fever, purulent nasal d/c,
    HA
  • Periorbital or facial swelling proptosis
  • Invasion of cavernous sinus leads to CN palsies
    (63, 4/5)
  • Rhizopus spp. are most common culprits
  • Not everyones favorite go-to fungus, Aspergillus
  • These fungi are vaso-invasive, so on PEx you may
    see black mucosal patches its not the mould
    youre seeing, its infarcted tissue
  • Treatment is with surgery FIRST and adjunctive
    amphoB

17
Endocarditis - 1
  • 2007 Modified Duke criteria 1 major 1 minor,
    or 3 minors

18
Endocarditis 2
  • Indications for surgical intervention in IE
  • Vegetations persistent after systemic
    embolization, anterior mitral leaflet veggies,
    embolic events in first 2 weeks of abx, increase
    in veggie size despite abx
  • Valvular dysfunction acute AI or MR with signs
    of ventricular failure, CHF unresponsive to
    medical tx, valve rupture
  • Perivalvular extension valvular
    dehiscence/rupture/fistula, new heart block,
    large abscess

19
Endocarditis 3
  • Native valves
  • PCN-susceptible Viridans streptococci and S.
    bovis MIC0.12
  • Penicillin G or ceftriaxone, or vanc x 4 wks
  • PenG or ceftriaxone PLUS gentamicin x 2 wks
    (synergy)
  • PCN-intermediate Viridans strep and S. bovis
    MICgt0.12, 0.5
  • PenG or ceftriaxone x 4 wks with gent for FIRST 2
    wks
  • Vanc x 4 wks
  • Staphylococcus aureus
  • NafcillinOSSA, oxacillinOSSA, or vancomycinORSA x
    6 wks
  • Enterococcus gentamicin ENTIRE TIME
  • Amp gent x 4-6 wks, vanc gent x 4-6 wks

20
Endocarditis 4
  • Prosthetic valves
  • PCN-susceptible Viridans streptococci and S.
    bovis MIC0.12
  • Penicillin G or ceftriaxone, x 6 wks, gent x
    FIRST 2
  • Vanc x 6 wks
  • PCN-int or resistant Viridans strep and S. bovis
    MICgt0.12
  • PenG or ceftriaxone x 6 wks with gent for all 6
    wks
  • Vanc x 6 wks
  • Staphylococcus aureus
  • Naf/oxOSSA or vancORSA PLUS rifampin x 6 wks,
    w/gent FIRST 2
  • Enterococcus gentamicin ENTIRE TIME
  • Amp gent x 6 wks, vanc gent x 6 wks

21
Endocarditis 5
  • TAKE-HOME MESSAGES FOR ENDOCARDITIS
  • Dont memorize the Duke criteria its intuitive
  • Gentamicin shortens the course for weak bugs
    (Low-PCN MIC Viridans group strep and S.bovis)
  • If Enterococcus is present, must use gent entire
    course
  • Prosthetic valve treatment is always 6 wks,
    sometimes with adjunctive abx (e.g., rifampin,
    gent) depending on bug
  • Staphylococcus treatment is always 6 wks

22
Intravascular infections 1
  • Staphylococcus aureus and Salmonella are
    associated with vascular (esp aortic) aneurysms
  • Think about this dx if high-grade (persistent)
    bacteremia in pt without endovascular material
  • Syphilis (Treponema pallidum) was once a major
    cause of aortitis late presentation of dz
  • Thoracic aortic dilatation with aortic
    regurgitation

23
Intravascular infections 2
  • Rocky Mountain spotted fever
  • Southeastern US (tick belt from Arkansas NC
    FL)
  • Rickettsia ricketsii attach to vascular
    endothelium leak
  • Fever, severe HA, rash in 90 (beware pts of
    color!), myalgias, focal neuro signs,
    thrombocyto, ARF, hypoNa
  • Doxycycline ASAP treat empirically no good
    acute dx tool

24
Lower respiratory tract infections - 1
  • Community-Acquired Pneumonia
  • Bugs Strep pneumo, Mycoplasma pneumoniae, H.flu,
    Chlamhydophila pneumoniae, respiratory viruses,
    Legionella
  • Outpatient tx
  • Previously healthy, no abx w/in 3 mos? Macrolide
    or doxy
  • Comorbidities? Respiratory FQ OR ß-lactam
    macrolide
  • Inpatient, non-ICU resp FQ OR ß-lactam
    macrolide
  • Inpatient, ICU ß-lactam PLUS resp FQ or
    azithro
  • ß-lactam choices cefotaxime, ceftriaxone,
    amp/sulbactam
  • Pseudomonas? pip/tazo, cefepime, imi/mero
    aminoglycoside
  • MRSA/ORSA? ADD vancomycin or linezolid

25
Lower respiratory tract infections - 2
  • Healthcare and Ventilator-Acquired Pneumonias
  • Bugs Pseudomonas, E.coli, Klebsiella,
    Acinetobacter, S.aureus
  • Increased risk for multidrug resistant (MDR)
    bugs?
  • Abx w/in 90d, current hospitalization 5d,
    high-freq of abx resistance in unit, risk factor
    for HCAP (hospitalization x2d in prior 90d,
    nursing home resident, home infusion, dialysis,
    close contact)
  • HAP/VAP if no known risk factors for MDR-bug
    (realistically, very rare)
  • Ceftriaxone or levoflox/moxi or amp/sulbactam or
    ertapenem
  • High risk for MDR-organisms or presenting with
    late-onset dz
  • Antipseudomonal ß-lactam cefepime, ceftaz, imi,
    mero, or pip/tazo AND cipro, levo, amikacin,
    gent, or tobra
  • If MRSA concern, ADD linezolid or vancomycin NOT
    daptomycin

26
Lower respiratory tract infections - 3
  • BMT and SOT recipients
  • Nocardia spp. if in lung, think of brain, too!
  • Beaded, branching, filamentous bacteria,
    acid-fast
  • Incidence has dropped due to TMP/SMX prophy use
    post-xp
  • TMP/SMX or imipenem empirical tx, awaiting
    susceptibilities
  • Get a CT of the head looking for ring-enhancing
    lesions
  • Aspergillus spp.
  • Marijuana smoking post-xp is a risk factor
  • Crescent sign on chest CT is buzzword
  • Vasoinvasive and tissue destructive
  • AmphoB, echinocandin (caspo/mica/anidula), or
    vori/posa

27
Lower respiratory tract infections - 4
  • Pneumocystis jiroveci (still called PCP)
  • CD4 200-250
  • HIV and transplant pts fludarabine (CD4-penic)
  • Nonproductive cough, fever, insidious SOB
  • Steroids if PaO2 lt70
  • Tx IV TMP/SMX or IV pentamidine
  • Inhaled only for prophy

28
Lower respiratory tract infections - 5
  • Mycobacterium tuberculosis
  • TST/PPD is a crappy test, but dont use anergy
    panel
  • KNOW THE THRESHOLDS FOR POSITIVE TST/PPD!!!

29
Lower respiratory tract infections - 6
  • Mycobacterium tuberculosis
  • Treatment always initiated with four drug RIPE
    regimen, at weight-based dosing
  • Isoniazid hepatotoxicity, anion gap acidosis (I
    in MUDPILES)
  • Rifampin inducer of metabolism of other drugs,
    orange body fluids, hepatotoxicity
  • Ethambutol optic neuritis (color blindness)
  • Pyrazinamide hepatotoxicity, nausea-inducing
  • Pulmonary TB total of 6 months treatment ALL ON
    DOT
  • First 8 weeks on RIPE if fully susceptible and
    smear negative at 2 month recheck, then OK to
    narrow to just INH Rifampin

30
Lower respiratory tract infections - 7
  • Histoplasma, Coccidioides, Cryptococcus
  • All gain entry through inhalation, then
    disseminate
  • Histoplasma Mississippi-Ohio River Valley,
    interstitial pneumonia, mucocutaneous ulcers,
    splenomegaly, marrow suppression, fibrosing
    mediastinitis, coin lesion in HIV
  • Coccidioides Desert SW (Mexican immigrants and
    eco-tourists), hilar adenopathy, arthralgias,
    erythema nodosum (can be mistaken for
    sarcoidosis)
  • Cryptococcus pneumonitis is usually
    subclinical, may have cryptococcomas of lung, can
    be normal hosts but if compromised (HIV,
    steroids, transplant) need LP

31
Enteric infections - 1
  • Norovirus
  • Rapid-onset explosive outbreak with quick
    resolution
  • Child exposures, cruise ships, congregate living
    facilities
  • Low infectious inoculum, highly transmissible
  • Vomiting precedes abd cramping, fever (lt50),
    watery diarrhea, constitutional sxs (HA, chills,
    myalgias) x 2-3d
  • Can cause deaths among the elderly
  • Treatment oral rehydration, supportive care
  • Antimotility and antisecretory drugs are okay to
    use

32
Enteric infections - 2
  • Dysentery bloody stools 4 main causes in US
  • Shiga toxin-producing E.coli (60 are O157H7)
  • Watery diarrhea becomes bloody in 1-5d abd
    cramps, no fever
  • Causes hemolytic-uremic syndrome if toxin reaches
    kidneys
  • Shigella (outbreaks uncommon more in developing
    world)
  • Campylobacter poultry, unpasteurized milk
    Guillain-Barré
  • Non-typhoid Salmonella poultry, pet reptiles
    and turtles
  • Treatments
  • Shiga toxin-producing E.coli Abx not
    recommended
  • Shigellosis, salmonellosis ciproflox, levoflox,
    azithro
  • Campylobacter jejuni azithro

33
Enteric infections - 3
  • Clostridium difficile diarrhea
  • Toxin assay for diagnosis, but dont attempt
    test-of-cure
  • Initial episode, mild-to-moderate
  • Metronidazole 500mg PO (not IV) q8h x10-14d
  • Initial episode, severe (WBC 15, Cr 1.5x
    premorbid level)
  • Vancomycin 125mg PO (not IV) q6h x 10-14d
  • Initial episode, severe and complicated by shock,
    megacolon
  • Vancomycin 500mg PO or pNGT PLUS metronidazole
    500 q8
  • If complete ileus, consideration for intrarectal
    vancomycin
  • First recurrence same as initial episode
  • Second recurrence vancomycin taper

34
HIV and AIDS - 1
  • HIV-1 predominates
  • HIV-2 limited to W. Africa
  • ssRNA retrovirus
  • AIDS is defined by
  • CD4 lt 200 cells/µL
  • CD4 lt 14
  • Presence of AIDS-defining illness at any CD4

35
HIV and AIDS - 2
  • ELISA highly sensitive
  • Better to have FP than miss a TP!
  • Western blot highly specific
  • Indeterminate Western blots are rare but can be
    caused by
  • Neoplasms, dialysis, thyroid dz, bilirubinemia,
    SLE, pregnancy, immunizations (tetanus,
    HIV) nephrotic-range proteinuria

36
HIV and AIDS - 3
  • Acute retroviral syndrome is a mononucleosis-like
    illness
  • Fever
  • Maculopapular rashThink syphilis, too!
  • Mucocutaneous ulcers
  • Pharyngitis tonsillar enlargement
  • Lymphadenopathy
  • Meningitis (infrequent)
  • DIAGNOSIS OF ACUTE HIV IS BY RNA, NOT Ab!!!

37
HIV and AIDS - 4
  • Initial mgmt Prophylaxis
  • CD4 gt 200, no prophylaxis necessary
  • CD4 lt 200
  • Pneumocystis jiroveci and Toxoplasmosis
  • TMP/SMX gt dapsone gt atovaquone
  • Aerosolized pentamidine prevents ONLY
    Pneumocystis
  • Do NOT need fluconazole for thrush prophylaxis
  • CD4 lt 50
  • Mycobacterium avium complex (MAI doesnt
    exist!)
  • Azithromycin 1200mg once weekly

38
HIV and AIDS - 5
  • Initial mgmt Antiretrovirals
  • For CD4 lt 200 or if AIDS-defining illness,
    everyone should get on ARVs
  • Recent (2009, so NOT on boards yet) evidence
    suggests starting ARVs during some acute OIs
    reduces mortality
  • For now, ABIM would say to start after
    stabilization, etc.
  • Btw 200-350, recommended to start
  • Over 350, decision btw pt and provider

39
HIV and AIDS - 6
  • Initial mgmt Antiretrovirals
  • Current testable recommendations are probably
    slightly out-of-date (circa 2008) field moving
    rapidly

40
HIV and AIDS - 7
  • Cryptococcal meningitis
  • Malaise, headache, N/V, low-grade fevers, without
    much meningismus or AMS
  • Think of dx also in ALL, Hodgkins, or recent
    steroid use
  • Get serum crypto Ag India ink is rarely used
  • Morbidity/mortality comes from increased ICP, so
    get opening pressure on LP and perform serial
    LPs
  • Can also place lumbar drain or ventricular drain,
    if needed
  • Amphotericin B flucytosine x14d for CNS disease
  • THEN switch to oral fluconazole and stay on it
    until CD4 gt 200

41
HIV and AIDS - 8
  • Antiretroviral side effects
  • ddI, d4T/stavudine, AZT/zidovudineNRTIs - lactic
    acidosis
  • TenofovirNRTI - Fanconi-like syndrome
    w/creatinine creep
  • AbacavirNRTI hypersensitivity rxn (if HLA
    B5701 present)
  • EfavirenzNNRTI - teratogenic, causes vivid dreams
  • NevirapineNNRTI - hepatotoxic if started with
    high CD4s, SO AVOID USING NEVIRAPINE IN PEP
    REGIMENS
  • IndinavirPI - nephrolithiasis
  • RitonavirPI - booster agent, tons of drug-drug
    interactions
  • AtazanavirPI - Gilbert-like syndrome of hyperbili
    jaundice

42
Antimicrobial adverse effects
  • Sulfa drugs rash, AIN/ARF, kernicterus in
    neonates
  • TMP hyperkalemia (decr renal tubular excretion)
  • ß-lactams marrow, seizures, AIN/ARF
  • Daptomycin rhabdomyolysis
  • Metronidazole disulfiram-like reaction with
    EtOH
  • Oxacillin hepatitis/transaminitis
  • Pentamidine pancreatitis, hypoglycemia
  • Amphotericin renal failure, rigors (meperidine)
  • Vancomycin red man (histamine release),
    nephro/ototox (??)
  • Aminoglycosides ototoxicity, c/i in myasthenia
    gravis
  • Linezolid marrow toxicity, MAOI activity
    (serotonin syndrome)

43
Infectious/septic arthritis - 1
  • Diagnosis
  • Arthrocentesis to eval for crystalline
    arthropathy
  • Generally gt50K cells/µL as threshold for septic
    joint
  • Look for Gram-positives 1 cause is S.aureus,
    followed by streptococci

44
Infectious/septic arthritis - 2
  • Monoarticular joint presentations
  • Late Lyme arthritis (Borrelia burgdorferi)
  • Knee gt shoulder gt ankle gt elbow gt TMJ gt wrist gt
    hip
  • Effusion is greater than the pain
  • Fluid can meet WBC criteria for septic joint, but
    uncommon
  • Diagnosis relies on serologies
  • Gonorrhea
  • Triad of migratory polyarthralgia, dermatologic
    lesions (macules, papules/pustules),
    tenosynovitis
  • Dx is by confirming genital or extragenital GC
    infection

45
STIs and GU tract infections - 1
  • Gonorrhea (Neisseria gonorrhoeae)
  • Gram-negative intracellular diplococcus
  • Purulent urethritis or cervicitis
  • Most cases resolve spontaneously treat to
    prevent disseminated gonococcal infection (DGI)
  • Fevers, asymmetric mono/oligoarticular arthritis
    (knee, ankle) or
  • Tenosynovitis - muscle pain overlying papules
    w/hemorrhage
  • Uncomplicated GU dz IM ceftriaxone or PO
    cefixime, x1
  • Extragenital dz or DGI IM ceftriaxone, x1
  • ALWAYS co-treat for Chlamydia with 1gm azithro,
    x1
  • NEVER use a quinolone for an STI on the boards!

46
STIs and GU tract infections - 2
  • Chlamydia trachomatis (and the catch-all, NGU)
  • Includes Ureaplasma urealyticum, Mycoplasma
    genitalium
  • Incubation period is longer for CT (1-4wks) than
    GC (2-6d)
  • Clear (non-purulent) discharge Gm stain WBC,
    no bugs
  • Treat with 1gm azithromycin PO, x1 or doxy 100
    q12 x7d
  • Pelvic inflammatory disease
  • Can be from GC or CT, sometimes vaginal anaerobes
  • Fitz-Hugh-Curtis purulent perihepatitis with
    mild LFT chgs
  • If pregnant, must admit the patient
  • Tx w/ceftriaxone x1, doxy and metronidazole x14d

47
STIs and GU tract infections - 3
  • Syphilis RPRnon-treponemal, confirmtreponemal
    MHA-TP, TP-PA
  • 1 painless chancre, 21d after contact,
    lasting 3-6 wks
  • 2 non-pruritic skin rash and mucous membrane
    lesions
  • Rough, red or brownish spots on trunk, palms and
    soles
  • Systemic symptoms with fever, LAD, sore throat,
    hair loss
  • Syphilitic hepatitis (1 2) cholestatic, but
    alk phos gtgt bili
  • Latent seroreactivity without e/o disease
  • Early latent if acquired syphilis within the
    prior year
  • Late latent unknown acquisition date
  • 3/Late evidence of end-organ damage PCN x 3
    wks
  • Neurosyphilis IV PCN x14d, desensitize in ICU
    if needed

PCN x1 PCN x1 PCN x1 PCN x3 wks
48
STIs and GU tract infections - 4
  • Herpes
  • Painful ulcerations of genital mucosa, usually
    from HSV-2
  • Remember primary genital lesion assoc w/ HSV
    meningitis
  • First episode ACV, famciclovir, or vACV x
    7-10d
  • Suppressive therapy does reduce viral shedding
    and prevent recurrent episodes
  • ACV 400 q12, famciclovir 250 q12, or vACV 500 q24

49
STIs and GU tract infections - 5
  • Trichomoniasis
  • If its moving fast on a wet prep, its
    Trichomonas vaginalis
  • Frothy, thin, foul-smelling d/c for women men
    often w/o sxs
  • Kill it with metronidazole 2gm po, x1 unless
    pregnant, then use metronidazole 500 q12h x7d.
    AVOID EtOH (disulfiram)
  • Bacterial vaginosis NOT an STI
  • Salt-and-pepper covered clue cell
  • Fishy odor, pH gt 5.0
  • Metro 500 q12h x7d

Clue cells Normal
50
Hepatic infections - 1
  • Hepatitis B
  • dsDNA virus
  • Blood and body fluids are source
  • Majority (95) of normal hosts will clear virus
  • Strong assoc w/HCC, esp among Asians who were
    vertically infected

51
Order after acute infection sAg ?
sAg,(anti)HBcIgM ? sAb. Because sAg drops
before sAb detectable, only way to confirm HBV
at that point is cIgM
52
Prevention of infectious diseases - 1
  • Endocarditis prophylaxis
  • 2007 ACC / IDSA guidelines changed this radically
  • Cardiac abnormalities for which prophylaxis is
    reasonable
  • Prosthetic valve or prosthetic material used for
    valve repair
  • Prior history of infective endocarditis
  • Congenital heart disease repaired or unrepaired
  • Cardiac transplant recipients with valvulopathy
  • Dental any manipulation of gingival tissue or
    periapical region of teeth, or perforation of
    oral mucosa
  • Amoxicillin 2gm 30-60 minutes before procedure
  • GI and GU tract procedures dont get prophylaxed
    for IE

53
Prevention of infectious diseases - 2
  • Malaria prophylaxis
  • Big question is, can chloroquine (CQ) be used or
    not?
  • Sensitive Mexico ? Costa Rica Argentina
    Turkey ? Iraq
  • Resistant All of Africa all of Asia Panama ?
    Argentina
  • If CQ sensitive Chloroquine or
    hydroxychloroquine
  • Start 1-2 wks before travel, take once weekly and
    x4 wks after
  • If CQ resistant (in general order of preference)
  • Atovaquone/proguanil 1-2d before travel, daily,
    x7d after home
  • Doxycycline 1-2d before travel, daily, x4 wks
    after home
  • Mefloquine 2 wks before travel, weekly, x4 wks
    after home
  • Psychotic episodes, szs, mental status changes
    with mefloquine

54
Prevention of infectious diseases - 3
  • Immunizations
  • NEVER give live virus vaccine to pregnant women
    or HIV-infected patients with CD4 lt 200
  • Live attenuated influenza, varicella, zoster,
    MMR, yellow fever (can be given in pregnancy if _at_
    risk)
  • Tetanus toxoid (as Td) and inactivated influenza
    are okay in pregnancy, preferably after 1st
    trimester
  • HAV HBV, pneumococcal meningococcal conjugate
    vaccines are prob safe in pregnancy no data

55
Prevention of infectious diseases - 4
  • Hospital precautions
  • Airborne varicella (incl zoster/shingles), TB,
    measles
  • Droplet H.flu, meningococcus, diphtheria,
    pertussis, Strep pharyngitis, adenovirus,
    influenza, RSV
  • Contact C.diff, norovirus, RSV, pediculosis
    (crabs), scabies, ORSA/MRSA, VZV
  • Shingles can come off airborne contact once
    dry, crusted
  • Handwashing is required for C.difficile
    infections alcohol-based sanitizers dont kill
    the spores

56
Prevention of infectious diseases - 5
  • Influenza remember drift
    year-to-year shift pandemics
  • Moving target unlikely pandemic H1N1 will appear
    on ABIM
  • Prophylaxing close contacts is appropriate use
    OST or ZNV based on what the question stem tells
    you about strain

57
Prevention of infectious diseases - 6
  • Meningococcus
  • Vaccine covers serogroups A, C, Y, W-135 but
    misses B, the major cause in the US (not included
    in any vaccine)
  • Everyone in the pts room will want
    treatment/prophylaxis (and we often prophylax
    many more than need it)
  • For the boards, its close contacts to
    respiratory droplets
  • Anyone with prolonged exposure (8h or more) w/in
    3 feet
  • Dorm roommate, but not classmates or other casual
    contacts
  • Anyone directly exposed to oral secretions w/in 1
    wk of dx
  • Boyfriend/girlfriend, anyone doing CPR or
    intubating pt
  • Rifampin 600 q12 x2d, ciproflox 500 x1, ceftriax
    250 x1

58
Prevention of infectious diseases - 7
  • Prevention of VAP
  • Use orotracheal intubation, vs nasotracheal/assist
    ed
  • Avoid NGTs use OGTs
  • Continuous aspiration of subglottic secretions,
    if available
  • Maintain adequate ETT cuff pressure, to occlude
    trachea and prevent leakage into the lower
    respiratory tract
  • Extubate as early as possible (minimize vent
    time)
  • Keep patient in semirecumbent position (30-45),
    esp when receiving an enteral feeding
  • Oral decontamination with chlorhexidine gluconate
    ( data)
  • Avoid sedation regimens that depress cough
    reflexes

59
Prevention of infectious diseases - 8
  • HIV PEP
  • Two different guidelines exist occupational and
    non
  • Start ARVs within 72h, ideally within first 20
    mins
  • Risk increases with the gauge of the needle
  • Hollow-bore needle gt scalpel gt suture needle
  • Data support using dual NRTI therapy by itself,
    but recommendation is to give the patient HAART
  • Combivir (zidovudine/lamivudine) or Truvada
    (tenofovir/emtricitabine) PLUS Kaletra
    (lopinavir/ritonavir) or efavirenz
  • AVOID NEVIRAPINE DUE TO RISK OF HEPATOTOXICITY AT
    HIGH CD4 COUNTS

60
Lightning round!
61
Streptococcus pneumoniae, an encapsulated
(halos) Gram diplococcus Strep pairs and
chains Staph clusters
62
Shingles from varicella-zoster virus in a young
male patient receiving chemotherapy
Ramsay-Hunt syndrome facial nerve paralysis,
ear pain, and loss of taste sensation in
anterior 2/3 of tongue, from VZV reactivation in
geniculate ganglion
63
Proper technique for measuring TST/PPD
(left) Scar from Bacille-Calmette Guerin (BCG)
vaccine (right)
64
Purpuric skin lesions of disseminated
meningococcemia Waterhouse-Friderichsen syndrome
is adrenal hemorrhage from N.meningitidis
65
Disseminated primary varicella in adults shows
multiple stages of healing, sometimes pustular
(left image) smallpox has all lesions at same
stage
66
Multiply parasitized RBCs with characteristic
headphone form (arrow) of Plasmodium
falciparum malaria
67
Nodular, hyperpigmented, sometimes violaceous
lesions of Kaposi sarcoma, caused by human
herpesvirus 8 (aka KS-HV)
68
Painless genital ulcer (chancre) of primary
syphilis
69
Slightly umbilicated papules of molluscum
contagiosum (a poxvirus) in an HIV-infected
patient.
70
Cellulitis from Streptococcus pyogenes. Using
adjunctive clindamycin for the first 72h is
reasonable, to shut of toxin production if
concern for TSS.
71
Plaques of thrush from Candida albicans in an
HIV-infected patient.
72
Thin, frothy cervical discharge from Trichomonas
vaginalis.
73
Lymphangitic spread of Sporothrix schenckii, a
thermal dimorphic mould. Rose gardening is the
buzzword. If fresh or brackish water exposure,
think Mycobacterium marinum.
74
Tinea versicolor from Malassezia furfur. Can also
cause sepsis in critically ill patients receiving
TPN.
75
Widened mediastinum from Bacillus anthracis
inhalation. Ciprofloxacin.
76
Ring-enhancing lesions of cerebral toxoplasmosis
in an AIDS patient. No reliable way to
radiographically distinguish toxo from CNS
lymphoma.
77
Pruritic skin lesions in webspaces, from the
scabes mite (Sarcoptes scabei).
78
Vaginal candidiasis. Single dose of fluconazole
150 or 200.
79
Cryptococcus neoformans on India ink prep. Halos
are the organisms polysaccharide capsule.
80
Measles exanthem but could also be a
morbilliform (measles-like) drug eruption.
81
Epidemiology - 1
Sensitivity probability of positive test in
those with disease TP / (TPFN) TP /
D Specificity probability of negative test in
those without disease TN / (TNFP) TN / D
82
Epidemiology - 2
PPV probability of having disease in those who
test positive TP / (TPFP) TP / T NPV
probability of not having disease in those who
test negative TN / (TNFN) TN / T
83
Prevalence what proportion has the disease right
now? _____________ cases____________ all those
with dz PLUS at risk for dz
84
Incidence what proportion develop the disease
over time? __________ new cases__________ all
those with dz PLUS at risk for dz
over time t
85
Epidemiology - 5
  • PPV and NPV depend on prevalence
  • Tests perform better when used in a higher
    prevalence group
  • This is why we dont test for influenza (usually)
    in the off-season

0 --------------------gt 2
Figure from Bill Miller
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