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Infectious Disease Board Review


Infectious Disease Board Review Jennifer Rogers 6/20/08 A 35 yo woman w/ HIV comes to f/u office visit. HIV was diagnosed 2 yrs ago when she presented w/ weight loss ... – PowerPoint PPT presentation

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Title: Infectious Disease Board Review

Infectious DiseaseBoard Review
  • Jennifer Rogers
  • 6/20/08

  • Meningitis
  • Actinomyces
  • Urinary Tract Infections
  • Secondary syphilis
  • Malignant otitis externa
  • HIV questions

Bacterial Meningitis
  • Strep. Pneumoniae is most common cause of
    bacterial meningitis 47, associated w/ 19-26
  • May occur in conjunction with pna, otitis,
    mastoiditis, sinusitis, endocarditis, s/p head
  • Often presents with fever, headache, nuchal
  • Neurologic complications including focal
    deficits, seizures, papilledema

  • Neisseria meningitidis is 2nd most common w/
    3-13 mortality
  • Meningococcal disease can manifest as three
    syndromes often with varying presentations from
    febrile illness to fulminant disease and death
    w/in a few hours
  • -Meningitis
  • -Meningitis with accompanying meningococcemia
  • -Meningococcemia without clinical evidence of

  • Predisposed in pts w/ C5-C9 deficient pt and
    those with dysfunctional properdin
  • Presents w/ acute onset headache, fevers, nausea,
    confusion, myalgias
  • 50 pts presents with petechial rash
  • Can progress to shock, DIC, purpura fulminans,
  • Focal neurological signs and seizures are less
    common compared to Strep pneumo.
  • Cardiac involvement myocarditis, pulm edema,
    heart failure is common in roughly 50 cases

Purpura Fulminans
  • Listeria monocytogenes GI portal of entry raw
    veggies, mild, cheese, meats. Associated w/
    extremes of age and immunosuppressed patients
  • Group B strep neonates and immunosuppressed
  • Gram Negative bacilli including Klebsiella,
    E.coli, Serratia, Pseudomonas following NSG
    procedures and as co-infection in pts w/
    disseminated strongyloidiasis hyperinfection
  • H. influenza type b- now rare given vaccination
  • Staph aureus- post surgical or following head

  • Indication for CT scan prior to LP seizure,
    papilledema, AMS, focal neurological deficit, h/o
    CNS dz, immunocompromised
  • CSF analysis

Bacterial Viral TB Crytpo
WBC count 1000-5000 50-1000 50-300 20-500
Diff PMN Lymph Lymph Lymph
Glu lt40 gt45 lt45 lt40
Pro 100-500 lt200 50-300 gt45
Empiric Therapy
  • If gram stain is negative or LP delayed, start
    empiric abx based on age and underlying condition
  • If gram stain is positive, target abx
  • Adjunctive dexamethasone should be considered in
    pts w/ acute bacterial meningitis, give before or
    with 1st dose of abx

Empiric Abx
Age 2-50 S. pneumo, N. meningitidis Vanc 3rd gen cephalosporin
Age gt50 S. pneumo, N. men, Listeria, GN bacilli Vanc 3rd gen cephalosporin ampicillin
Basillar skull fracture S. pneumo, H.influ, group A strep Vanc 3rd gen cephalosporin
Post-NSG or trauma Staph, Gram negative Pseudomonas Vanc either ceftaz, cefepime, or meropenem
CSF shunt Staph aurues, CONS, GNR Vanc either ceftaz, cefepime, or meropenem
  • 1. A 45 yo woman who has a 3-day h/o progressive
    earache and fever is hospitalized after becoming
    unresponsive. Medical history is unremarkable
    she has no allergies and she takes no
    medications. On physical exam on admission,
    temperature is 40oC, pulse is 120/min,
    respiration rate is 32/min, and blood pressure is
    80/50 mm Hg. The patient is obtunded and had
    meningismus. The leukocyte count is 25,000 uL w/
    25 band forms, and the platelet count is
    20,000/uL. Lumbar puncture is performed CSF
    fluid exam shows Appearance cloudy, WBC
    2500, 99 PMNs, glucose 20mg/dL, protein
    240mg/dL. A gram stain of unspun CSF fluid shows
  • Which empiric treatment regimen should be
  • PCN dexamethasone
  • Ceftriaxone dexamethasone
  • Vanc dexamethasone
  • Vanc ceftriaxone dexamethasone
  • Vanc ceftriaxone

  • 2. A 24 yo woman is brought to the ED
    because of fever, photophobia, and a stiff neck.
    On physical exam, the patient is irritable. Temp
    is 40oC. There is nuchal rigidity and a purpuric
    rash is seen on dependent areas of the body.
    While in the ED, the patient develops respiratory
    distress and requires intubation. She is
    subsequently admitted to the ICU.
  • During transfer, the patient is isolated
    with droplet precautions, and all health care
    workers wear masks and use the appropriate
    barriers. Lumbar puncture is done in the ICU,
    and CSF exam shows gram negative diplococci.
  • Which of the following health care workers
    requires antibiotic prophylaxis?
  • All staff who were present in the ED and ICU when
    the patient was in these areas.
  • All staff who examined the patient in the ED and
  • The resident who intubated the patient in the ED.
  • Prophylaxis is not required for any staff.

  • A 26-yo man comes to the ED w/ 5 days of HA,
    stiff neck, fatigue, N/V, myalgias, and weakness.
    He has just returned from a vacation in Jamaica,
    where he spent most of the day on the beach and
    much of each evening socializing in bars. He did
    not have any sexual contact on the trip. Medical
    history is unremarkable.
  • On PE, temp is 38oC, pulse 78/min, RR 18/min, BP
    118/72. There is marked pain on flexion of the
    neck and moderate nuchal rigidity.
    Cardiopulmonary and abd exam are nml. The
    extremities are nml. There is mod photophobia.
    The CN are intact. Motor strength appears
    unimpaired, but the pt develops muscle pain
    during strenuous activity. Reflexes are
    symmetric and slightly hyperactive.
  • Labs Hg 15.1 g/dL, Hct 47, WBC 9800/uL w/ 72
    PMN, 11 lymph, 13 eos, 4 monos. Plt
    288,000/uL, BUN 14, CR 0.8, electrolytes nml,
    LFTs nml.
  • LP is performed. Opening pressure is 240cm H20.
    CSF WBC is 290/uL w/ 70 lymphs, 21 eos, 9
  • Which of the following is the most likely
  • Angiostrongylus cantonensis
  • Trichinella spirilis
  • Strongyloides stercoralis
  • Entamoeba histolytica
  • Treponema pallidum

  • A 35yo woman is hospitalized b/c of fever, HA,
    ataxia, confusion, and loose stools. The pt
    underwent cadaveric kidney transplant 12 mo ago
    for ESRD. Current meds are prednisone and
    azathioprine. She is allergic to penicillin,
    which causes anaphylactic shock. However, she
    has received cephalexin in the past w/o a
  • On PE, temp is 39.4oC, pulse 100/min, RR is
    30/min, and BP 90/60. The pt is confused and is
    oriented to person but not to place or time. Her
    neck is supple. The plantar response is extensor
  • The WBC count is 18,500/uL w/ 20 bands. LP is
    performed and CSF shows WBC 1500/ul w/ 50 PMN
    and 50 lymphs, glucose 30 mg/dl, protein
    300mg/dl, gram stain negative.
  • In addition to vancomycin, which of the following
    antibiotics should be initiated?
  • Ceftriaxone
  • Ceftriaxone plus trimethoprim-sulfamethoxazole
  • Ceftriaxone plus levofloxacin
  • Ceftriaxone plus azithromycin

  • A 30 yo woman is hospitalized following the
    sudden onset of severe HA, stiff neck, and
    vomiting. Evaluation reveals a subarachnoid
    hemorrhage secondary to a leaking aneurysm. The
    aneurysm is repaired surgically and a
    ventriculostomy tube is placed to drain CSF.
  • Four days postoperatively, the pt develops
    fever, worsening headache, and confusion. On PE,
    her temp is 39.4oC, pulse 100/min, RR is 24/min,
    BP is 120/70. The ventriculostomy tube is
    draining clear CSF. All surgical sites are clean.
  • The leukocyte count is 15,000/uL w/o a left
    shift. U/A and CXR are nml. CSF analysis is WBC
    300/ul w/ 90 PMN, WBC 900/ul, glucose 30 mg/dl,
    protein 150mg/dL, gram stain negative, culture
  • Which of the following empiric antibiotics should
    be initiated?
  • Vancomycin
  • Vanc rifampin
  • Vanc ceftriaxone
  • Vanc cefepime
  • No therapy is indicated

  • Subacute-to-chronic infection caused by
    filamentous, gram-positive, non-acid fast,
    anaerobic bacteria.
  • Part of normal oral flora
  • Infection is characterized by suppurative and
    granulomatous inflammation with abscess and sinus
    tract formation with sulfur granules
  • Most often results in cervicofacial infection 50
  • Presents in pts predisposed to facial infection
  • - dential caries, gingivitis, tooth
  • -underlying DM, immunosuppression, oral
    malignancies or radiation

Cervicofacial actinomyces
  • Most common manifestation, 50-70 of cases
  • Presents as slow growing, non-tender indurated
  • Progresses to multiple abscess and fistula
    formation with pain, trismus, and yellow purulent
    discharge (sulfur granules)
  • Usually involves the mandible, but can infect
    any structure including cheek, chin, submaxillary

Thoracic and Abdominal
  • Thoracic actinomyces 20 of cases is usually due
    to aspiration.
  • Also occurs via hematogenous spread or after
    esphageal perforation
  • Presents as pulmonary mass or infiltrate on
  • Abdominal actinomyces often presents as slow
    growing mass/tumor often in ileocecum following
    in pts w/ h/o bowel surgery or foreign body
  • Pelvic infection can occur in women with
    long-standing IUCD

Diagnosis and Treatment
  • Culture, monoclonal antibody stain
  • Treatment
  • Mild infections treat w/ oral Penicillin V
    2-4g/day divided q6hrs for 2-6 months
  • Serious infections Penicillin G IV 2-4g/day
    divided q6hrs x 4-6 weeks, followed by oral PCN V
  • Surgical excision required for complicated
    abscesses and fistulas

Urinary Tract Infections
  • Asymptomatic UTI in pregnancy treat w/ 3-7 days
    of sulfisoxazole, amoxicillin, or nitrofurantoin
    or single dose of fosfomycin. Obtain f/u culture
  • Symptomatic UTI in pregnancy treat w/ 7 days of
    amoxicillin, nitrofurantoin, or cephalexin
  • Catheter associated UTI Treat if symptomatic
    based on culture results, replace catheter.
  • Asymptomatic candiduria do not treat unless
    neutropenic or recent urinary tract surgery
  • Symptomatic candiduria treat based on culture.
    Fluconazole, flucytosine, or IV amphotericin.
    Bladder irrigation not recommended.

Recurrent UTIs
  • Common infection representing re-infection, not
  • Risk factors include sexual intercourse,
    spermicides, diaphragm use, and postmenopausal
  • Treatment tailored for the individual patient
  • Options include
  • Daily low-dose antibiotic prophylaxis
  • Postcoital prophylaxis
  • Patient initated antibiotic treatment

  • 4. A 32-year old sexually active woman w/ type 1
    DM is evaluated b/c of recurrent UTIs. She has
    had three episodes this year. The most recent
    episode occurred 2 weeks ago.
  • Physical exam, including vital signs, is nml.
    U/A is nml except for the microscopic exam which
    sows 4bacteria.
  • Which of the following management strategies is
    the most appropriate at this time?
  • Patient-initiated empiric antibiotic therapy
  • Continuous standard-dose antibiotics
  • U/A and culture at the onset of dysuria
  • Post-coital empiric antibiotic therapy

Malignant Otitis Externa
  • An invasive infection of the external auditory
    canal and skull base
  • Often occurs in elderly patients with diabetes
    mellitus or immunodeficiency.
  • Pseudomonas aeruginosa is the usual pathogen, but
    can also include staph aureus, proteus,
    klebsiella, and candida

Malignant Otitis
  • Clinically presents with otalgia and otorrhea
    that is not responsive to topical antibiotics
  • Severe, often nocturnal pain
  • Can progress to osteomyelitis of TM w/ CN palsies
  • Diagnosis Obtain CT or MRI, culture, and
    consider biopsy to r/o malignancy

Malignant Otitis Treatment
  • Treatment directed at anti-pseudomonal
  • Ciprofloxacin 400mg IV q8hrs until clinical
    improvement then PO Cipro for 6-8 weeks
  • No role for topical antibiotics
  • If aspergillus, treat with liposomal amphotericin
    B for gt12 weeks.

Primary Syphilis
  • Primary syphilis presents as a painless
    ulcerative chancre approx 3 weeks after exposure
    to Treponema pallidum
  • Primary lesion usually resolves and progresses to
    secondary syphilis 2-8 weeks later
  • Secondary syphilis is characterized by
    hematogenous dissemination in the skin, liver,
    lymph nodes usually resolves and progresses to
    latent, tertiary or neurosyphilis
  • Latent syphilis is asymptomatic infection with
    positive serology
  • Tertiary syphilis includes CNS, cardiovascular
    and gummatous disease involving skin, soft
    tissues, bones, and internal organs.
  • Neurosyphilis now most often seen w/ HIV,
    involves CNS, meninges, vascular sxs w/
    meningitis, CN palsies, tabes dorsalis

Secondary Syphilis
Diagnosing Syphilis
  • Darkfield microscopy
  • Nonspecific tests rapid plasma reagin (RPR) and
    Veneral Disease Research Laboratory (VDRL) used
    as screening tests, reported as titer and
    followed for response to tx
  • Specific treponemal tests fluorescent treponemal
    antibody absorption (FTA-ABS) assay and the
    microhemaglutination assay (MHA-TP) used as
    confirmatory tests
  • False positive nonspecific and treponemal tests.
    FP treponemal tests SLE, HIV, ESLD, IVDU
  • False negative occur prior to development of abs

  • 1. Primary, secondary or early latent (less than
  • -Benzathine PCN G 2.4million units IM x1
  • -PCN allergic, nonpregnant doxycycline 100mg
    bid x14 days
  • -In pregnancy, PCN desensitization
  • 2. Late latent, tertiary or unknown duration
  • -Benz PCN G, 2.4 million units IM q week x3 weeks
  • -PCN allergic doxycycline 100mg bid x4 weeks
  • 3. Neurosyphilis
  • -PCN G 3-4 million units IV q4hrs x10-14 days

  • A 24-yo woman who is 4 months pregnant has an
    abnormal rapid plasma reagin test for syphilis
    (titer of 1128) and a reactive fluorescent
    treponemal antibody absorption (FTA-ABS) assay.
    She is asymptomatic and has no h/o of STDs. Her
    pregnancy has been uncomplicated, and her only
    medication is a prenatal vitamin. Physical exam,
    including pelvic exam, is nml for her stage of
  • The patient developed hives when taking
    amoxicillin 4 yrs ago. At that time, she had a
    sore throat, fatigue, and enlarged cervical lymph
    nodes. Symptoms lasted for more than 1 month and
    did not respond to the course of amox.
  • Which of the following is the most appropriate at
    this time?
  • Perform skin test for PCN allergy
  • Begin PCN now
  • Desensitize, then begin PCN
  • Begin ceftriaxone now
  • Begin doxycycline now

  • A 40yo man w/ AIDS has a 2 week h/o of headache
    and subtle mental status changes. General exam,
    including a detailed neurologic exam is
    unremarkable. A CT scan of the brain is nml. LP
    is performed CSF shows WBC 40/ul w/ 80
    lymphocytes, glucose nml, protein nml, VDRL
  • The patient had a documented episode of
    angioedema after a penicillin injection 1 year
  • Which of the following is the most appropriate
    management at this time?
  • Obtain radioallergosorbent tests for the major
    penicillin determinant
  • Hospitalize for desensitization in preparation
    for PCN therapy
  • Begin doxycyline now
  • Begin ceftriaxone now

  • A 35 yo woman w/ HIV comes to f/u office visit.
    HIV was diagnosed 2 yrs ago when she presented w/
    weight loss, Pneumocystis jiroveci pneumonia, a
    CD4 count of 92/uL, and HIV RNA viral load of
    105,000 copies/ml. The pna was treated
    successfully, and highly active antiretrovial
    therapy zidovudine, lamivudine, and efavirenz
    was begun. The pt adhered to her medication
    regimen and had an excellent response. Her CD4
    cell count increased to 323/uL and her plasma HIV
    RNA viral load became undetectable w/in 6 mo.
  • Approximately 1 yr ago, she began missing
    appointments. At a follow-up 4 mo ago, her viral
    load increased to 878 copies/ml and at todays
    visit the viral load is 5375 copies/ml. Her CD4
    count remains stable at 300/uL and she continues
    to be asymptomatic. She now acknowledges
    occasionally missing medication doses.
  • Which of the following is the appropriate
    management at this time?
  • Continue the current regimen
  • Substitute nevirapine for efavirenz
  • Add nevirapine to the current regimen
  • Ordern an HIV genotype reistance assay
  • Recommend a drug holiday until she becomes

  • A 38yo nurse is evaluated b/c of an abnormal
    ELISA for HIV discovered when she attempted to
    donate blood. A follow-up western blot had an
    indeterminate result.
  • The patient is asymptomatic. She has worked on a
    medical/surgical hospital floor for 12 years, has
    been married for 16 yrs, and has 3 children. Her
    husband and children are well. She and her
    husband have a monogamous sexual relationship and
    neither spouse has ever used ilicit drugs. The
    patient has never received a transfusion. She
    had a needle-stick injury 8 years ago from an HIV
    negative source and did not receive
    antiretroviral post-exposure prophylaxis.
  • On PE, she appears anxious but well. Exam is
    nml. Her CD4 count is nml, but her plasma HIV RNA
    viral load is slightly elevated at 82 copies/ml
    (nml lt75)
  • Which of the following is the most appropriate
  • Recheck the plasma HIV RNA viral load now
  • Recheck the HIV serologic study in 3 months and 6
  • Begin highly active antiretroviral therapy now
  • Begin highly active antiretroviral therapy if her
    CD4 count decreases to less than 350/uL or she
    becomes symptomatic.

  • A 42yo man w/ HIV infection is evaluated b/c
    of a 5 week h/o of night sweats and weight loss
    of 2.2kg. He moved to NYC from his home in the
    Dominican Republic 3 mo ago, when he started
    HAART. His CD4 count before starting HAART was
    240/ul. Following treatment, his CD4 count rose
    to 350/ul and his HIV RNA VL fell from 500,000
    copies to an undetectable level. The pt takes no
    other medications.
  • PE is nml except for an enlarged right
    cervical lymph node. A CXR is nml. A lymph node
    is subsequently excised and stains positive for
    acid-fast bacilli.
  • Which of the following is the most likely
  • Mycobacterium avium complex
  • Mycobacterium marinum infection
  • Mycobacterium kansaii
  • Mycobacterium tuberculosis
  • Immune reconstitution inflammatory syndrome

  • A 35yo man is evaluated b/c of a lesion on his
    right arm that he noticed 2 weeks ago. The pt has
    a 4yr h/o of HIV, most likely acquired after
    having sex w/ another man. He has been
    asymptomatic until now and has never received
    HAART. His lowest CD4 count was 382/uL and his
    plasma HIV RNA vl has ranged from 15,000 to
    20,000 copies.
  • On PE, he appears well. Vitals are nml. There is
    a small, raised, nontender violaceous lesion on
    his right arm. Exam of the skin and mucous
    membranes is nml. There is no lymphadenopathy or
    peripheral edema. Abd and rectal exam are nml. A
    stool specimen is negative for blood.
  • WBC nml, CD4 count 402, HIV RNA VL 14,000, LFTs
    nml, Cr nml, CXR nml. Path exam of the biopsy
    specimen shows spindle cells c/w Kaposis
  • Which of the following is the most appropriate
  • Begin HAART and systemic chemotherapy for
    Kaposis sarcoma
  • Begin HAART, defer chemo until HIV infection is
  • Begin HAART, defer chemo unless visceral or
    extensive skin involvement develops
  • Begin system chemotherapy, defer HART until after
    chemo is completed
  • Defer both HAART and chemo until the pt becomes

  • A 44yo man w/ HIV is hospitalized b/c of 1 week
    of progressive left lower extremity weakness and
    inability to walk. For the past 3 months, he has
    had rapid weight loss, night sweats, and
    low-grade fever. Although HIV infection was
    diagnosed 2 yrs ago, the pt never returned for
    f/u. His CD4 count at that time was 88.
  • On PE, he appears cachectic and chronically ill.
    Temp is 38.1oC. He has oral thrush, mild
    splenomegaly, bilateral LE weakness and
  • Labs Hg 11.8 g/dL, HCT 34, WBC 2800/ul, plt
    98,000/ul, LFTs nml.
  • MRI of the brain
  • LP is performed, CSF OP nml, WBC 21/ul 98
    lymph, 2 PMN, WBC 1/ul, protein 85, glu 66,
    india ink neg, crypto ag neg. PCR positive for
    polyomavirus JC and negative EBV.
  • Which of the following is the most appropriate
  • IV cidofovir
  • IV acyclovir
  • IV dexamethasone and radiation therapy

  • A 25yo woman, who is 8 wks pregnant, is referred
    by her OB for management of newly diagnosed HIV
    found during routine prenatal screening. This is
    her first pregnancy. She had never been tested
    for HIV before and does not know how long she has
    been infected.
  • On PE, she appears well. Vitals and exam are nml
    except for thrush.
  • Labs Hg 10.2, Hct 31, WBC 3900/ul, LFTs nml, Cr
    nml, CD4 72/ul, HIV RNA VL 39,900 copies/ml.
  • Which of the following is the most appropriate
    for treatment of HIV infection?
  • Begin zidovudine, lamivudine, and nelfinavir now
  • Begin lamivudine, tenofovir, and efavirenz now
  • Defer HAART until the end of her 1st trimester
  • Defer HAART until the end of her 2nd trimester