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Flashcards in Infectious disease Deck (370):


rocephin 250mg IM or cefixime 400mg po one dose

Alternate: cefpodoxime 400mg po x 1 or
azithromycin 2 gm po x 1



doxycycline 100mg bid x 7 days or azithromycin 1 gm po x 1

Alternate: emycin 500mg po QID or
levofloxin 500mg daily x 7 days


syphilis <1 year

benzathine PCN 2.4 MU IM one dose
Alternative: doxycycline 100mg BID x 14 days


syphilis > 1 year

benzathine PCN 2.4 MU IM weekly x 3 weeks

Alternate: doxycycline 100mg BID x 30 days



aqueous PCN G 3-4MU IV every 4 hours or 24 MU continuous IV x 10-14 days

alternate: ceftriaxone 2 gm IV daily x 10-14 days


PID *outpatient

rocephin 250mg IM x 1 plus doxycycline 100mg BID x 14days, +/- flagyl 500mg BID x 14 days


PID *inpatient

cefoxitin or cefotetan IV plus doxy 100mg BID po X 14 days

alternate: amp/sulb IV plus doxy as above



rocephin 250mg IM x 1 plus doxy 100mg BID x 10 days

alternative:ofloxacin 300mg po BID x 10days or
levofloxacin 500mg daily x 10 days


screening for chlamydia

best test: DNA/RNA test by PCR on urine

all sexually active female 1 sex partner
*inconsistent use of barrier contraception


chlamydia tx in pregnancy

azithromycin 1 gm po x 1


GC tx in pregnancy

rocephin and azith, if PCN allergy-azith 2gm po x 1


syphilis tx in pregnancy

benzathine PCN
**if PCN allergy-desensitize to PCN and tx with PCN!!


tx herpes in pregnancy

acyclovir for acute and suppressive therapy
*last month of pregnancy to prevent recur and need for c section


diagnostic criteria for PID

*lower abd pain
*cervical motion tenderness, adnexal tenderness
*absence of other diagnosis
*mucopurulent cervicitis


complications of PID

*ectopic pregnancy


organisms involved in PID

*GC, chlamydia
*M,genitalium, M. hominis


primary syphilis symptoms and diagnosis

symptoms: single painless,indurated lesion, painless inguinal adenopathy
Dx:dark field exam, VDRL is negative


secondary syphilis, symptoms

*rash, arthritis, hepatitis, nephrotic syndrome
*condylomata lats, aseptic meningitis, generalized lymphadenopathy


latent syphilis

positive serology but no clinical manifestations


tertiary syphilis

CV:aortitis, AR,aneuysm, coronary ostial stenosis
CNS:CVA, encephalitis;general paresis (20yr infection)-personality, affect, intellect, speech;Tabes dorsalis (25-30yr)-ataxia,wide base gait,paresthesia, areflexia,AR pupil, demyelination etc


syphilis serology

*RPR,VRDL:screening or quant. of serum antibody,follow titer after treatment
*treponemal tests: FTA-ABS
TPPA-used to confirm , remain positive after treatment


indications for lumbar puncture w suspect syphilis

*neuro s/s
*RPR or VRDL titer >1:32
*tx failure
*HIV+ w CD4 <350


CSF findings in syphilis

Increased:protein, lymphocytes
Positive:VDRL, FTA-ABS


negative FTA-ABS on CSF

rules out neurosyphilis


if VRDL is + and FTA-ABS is - then

false + VDRL


HSV 1&2 are

double stranded DNA virus that either can cause oral or genital infection


More common cause of herpes labialis



more common cause of genital herpes



HSV initial episode may have these S/S

*fever, headache, malaise, myalgia, pain
*dysuria, vaginal and urethral discharge
*tender inguinal lymphadenopathy
*aseptic meningitis


Diagnosis of HSV

viral culture or PCR
*type specific serology testing-only useful for diagnosing chronic
*PCR on CSF-best to dx herpes encephalitis


Tx first episode of HSV

acyclovir 400mg TID
famciclovir 250mg TID
valacyclovir 1 gm BID
* all for 7-10 days


Tx recurrent HSV

acyclovir 400mg TID X 3-5days
famciclovir 250mg TID X 7-10days
valacyclovir 1gm BID X 7-10days


suppression of HSV

acyclovir 400mg BID
famciclovir 125mg BID
valacyclovir 500mg daily


Tx severe HSV or herpes encephalitis

IV acyclovir


other herpes simples virus syndromes

*herpetic whitlow
*Bells palsy


HPV-human papillomavirus

double stranded DNA


HPV types assoc with anogenital warts

6 & 11


HPV virus assoc with cervical cancer

16, 18, 31, 33, 45


HPV quadravalent vaccine is approved for males and females ages 9-26 are

6, 11, 16, 18



yellow, frothy discharge
pH >or= 4.5
dysuria, strawberry cervix
*Dx: wet mount or culture, OSOM rapid test
*TX:flagyl or tinidazole 2gm single dose


bacterial vaginosis (gardnerella)

*thin whitish dischg,odor. pH>4.5, amine odor w KOH
*clue cells on wet mount(culture not needed), rapid tests
*tx:flagyl 500mg BID x 7days or vaginal clindamycin cream 2% nightly x 7 days



*thick curd dischg vaginal erythema,pruritis, dysuria,pH<4.5
*TX: fluconaxone 150mg x 1, miconazole 100mg vaginal tablet. or clotrimazole 100mg vaginal tablet once daily x 7 days


atrophic vaginitis

*watery, yellow discharge, dyspareunia, vagina thin and pale
*wet mount:numerous WBC, no bacteria, negative KOH
*tx; topical estrogen


HIV + class 1

asymptomatic HIV infection or low viral load <1500RNA copies


HIV+ class II

symptomatic HIV infection, AIDS, acute seroconversion or high viral load >1500 RNA copies


prophylaxis against HIV after percutaneous injury, LOW RISK exposure

*class 1: 2 drugs x 4 weeks
*class II: 3 drugs x 4 weeks
*unknown status: no tx or 2 drugs x 4 wks if risk factors for HIV


prophylaxis against HIV infection after percutaneous injury with HIGH RISK exposure

class 1 & class II & unknown status ALL:3 drugs X 4 weeks


HIV low risk exposure

injury caused by solid needles, superficial injuries


HIV high risk exposure

injury by large bore hollow needle, deep puncture, device visible contaminated with blood, needle used in a patient artery or vein


HIV 2 drug regimen for prophylaxis



HIV prophylaxis 3 drug regimen

*ritonavir plus atazanavir
*ritonavir plus darunavir


risk of HIV transmission from sexual exposure

*receptive anal intercourse: 1-30%
*insertive anal or receptive vaginal: 0.1-10%
*insertive vaginal intercourse: 0.1-1%
Risk is lower with oral intercourse


Indications for Postexposure prophylaxis HIV:
*persons exposed to known HIV+ source patients
*persons exposed to select high risk population with unknown HIV status
*men who have sex w men or both men and women

*commercial sex workers, perpetrators of sexual assault
*IVDU, persons with hx of incarceration
*persons from country where sero+ of HIV is >/= 1%
*persons having sex with someone in one of these groups


greatest benefit of HIV prophylaxis medications

*when started within 36 hours after exposure


Evaluation of HIV+ patient
*PPD5mm=INH x 9 months)
*hepatitis A,B,C serology, toxoplasma & CMV serology
*Vaccines: Hep A&B,influenza, pneumococcal, H. inf type b
*PAP baseline, 6 mo then yearly if normal

*anal screen for HPV
*CD4 cell count,genotype for antiretroviral drug resist., G6PD
*RNA viral load


start antiretroviral tx in HIV+ when CD4 count



start pneumocystis prophylaxis in HIV+ patient when CD4 count



HIV+ patient with +toxoplasma antibody, start prophylaxis when CD4 count


*Bactrum, or dapsone + pyrimethamine + leucovorin


HIV+ patient start prophylaxis for M. avium when CD4 count



Best predictor of prognosis in HIV

HIV RNA viral load


Pregnancy and HIV infection

*all start on 3 drug tx regardless of CD4 count to prevent mother to fetal transmission
*Preferred regimen:Zidovudine + laivudine + lopinavir/retonavir


diseases seen in HIV+ patient with CD4 count >500

vulvovaginal candidiasis


diseases seen in HIV+ patient with CD4 counts 200-500

*hairy leukoplakia, oral candidiasis, recur HSV, varicella-zoster,seborrheic dermatitis, recur bacterial infections, TB, kaposi sarcoma, peripheral B cell non-hodgkins lymphoma


disease in HIV+ patient with CD4 counts 50-200



diseases seen in HIV+ patient with CD4 counts <50

*MAC, cryptococcosis, CMV, cryptosporidiosis
*histoplasmosis, toxoplasmosis, multifocal leukoencephalopathy
*CNS lymphoma


Acute (HIV) retroviral syndrome

*s/s:skin rash, mouth ulcers,pharyngitis, gen. lymphadenopathy, oral candida

*mono like S/S 2-6wks after initial exposure
*dx confirmed: HIV RNA usually >50,000 copies or P24 antigen
*Rx: HAART x 6 months


early initiation of antiretroviral therapy reduces

*the sexual transmission of HIV
*the rate of disease progression


Indications for antiretroviral therapy

*CD4 <500, symptomatic HIV dz w any CD4 or HIV RNA
*acute retroviral syndrome (6 months)
*pt w hx of AIDS defining illness, HIV assoc nephropathy
*pregnant, active coinfection w Hep B or C
*after high risk exposure-4 weeks


most important test to follow after start of antiretroviral therapy for HIV

viral load


therapy for HIV

*2 nuclosides + 1 protease inhibitor or 1 nonnucleoside
*2 nuclosides + 2 protease inhibitors


recommended antiretroviral therapy

*efavirenz + (lamivudine or emtricitabine) + (zidovudine or tenofovir)
*(lopinavir + ritonavir) + (lamivudine or emtricitabine) + zidovudine


indications for changing antiretroviral therapy :

*failure to achieve HIV viral load

*3 fold or > increase from the nadir not attributed to intercurrent infections
*detection of viral isolate resistant to a drug
*drug toxicity, clinical progression of disease


in treating HIV patient, if see treatment failure

do viral resistance testing


IRIS-immune reconstitution inflammatory syndrome
*can see usually in pt with advanced HIV disease
*presents within 4 weeks of starting HAART
*present with odd presentations, inclluding infections

*see viral load decrease, CD4 decrease
*due to rapid expansion and dysregulation of antigen specific T cell response


indications for prophylaxis for pneumocystis
*CD4 <14
*prior PCP or persistent fever
*hx oropharyngeal candidiasis

*primary or secondary prophylaxis can be discontinued if CD4 count is >200 for >3 months
*pt not HIV but are on immunosuppressive meds or have underlying acquired or inherited immunodeficiency


tx options for pneumocystis prophylaxis

*bactrim ds one a day
*dapsone 100mg daily
*atovaquone 1500mg daily
combo of dapsone,pyrimethamine, leucovorin
pentamidine 300mg aerosol daily


Pneumocystis Jerovecii pneumonia-clinical features and diagnosis

*gradual onset of cough, fever, dyspnea
*CXR-bilateral intersitial infiltrates +/- pneumothorax
*Dx: sputum w direct staining
BAL, transbronchial biopsy


tx choice for pneumocystis Jerovecii pneumonia

TMP/SMX 15-20mg/kg oral or IV


CNS disease in AIDS:
*toxoplasmosis-mult ring enhancing lesions
*brain abscess-single or mult ring enhancing lesions
*CNS lymphoma-CD4<50, **Epstein Barr antibody + in 100%

*AIDS dementia-MRI=atrophy
*vasc.myelopathy-weakness, spastic, hyperreflexia
*multifocal leukoencephalopathy_JC virus
*radiculopathy, myopathy (HIV virus or AZT)
*peripheral neuropathy(HIV,HIV meds can cause)


cryptococcal meningitis

*most common cause of meningitis in HIV patients
*headache may be only symptom

Dx: India ink on spinal fluid in 75%, crypt antigen on blood,CSF
Tx:amphotericin B +/- flucytosine
serial spinal taps to decrease pressure if incr neuro signs
fluconazole prophylaxis after tx of acute infection


Histoplasmosis in HIV

*fever,hepatosplenomegaly, lung infiltr., splenic calcification
*dx: serum and urine H capsulatum antigen
*tx: amphotericin B for 7-14 days then itraconaole prophylaxis


diarrhea in AIDS

*bacterial: salmonella,shigella,campylobacter, M. avium
*viral: CMV, HSV, HIV

*drugs: DDI, protease inhibitors
*Protozoa: cryptosporidium, giardia, E. histolytica


CMV infection in AIDS

*features: retinitis, esophagitis, colitis
*Tx: ganciclovir or foscarnet IV, valganciclovir orally


Hepatitis C coinfection with HIV

*increased rate of progression to cirrhosis and HCC
*tx; 48 weeks regardless of genotype
*NO ribovirin if on AZT or DDI


Hepatitis B coinfection with HIV

*increased risk of chronic infection and cirrhosis
*long term tx
* if HIV needs tx, tx with 2 drugs that are also active against HBV (lavivudine, tenofovir, emtricitabine)
*if only need tx HBV, dont use above


clinical presentation of endocarditis

*fever, wt loss, myalgia, arthralgia, back pain , splenomegaly
*heart murmur, clubbing, petechiae, subungual hemorrhages
*Osler's nodes
*roth spots
*janeway lesions


common organism with native valve endocarditis

*streptococcus, staph. aureus
*HACEK: haemophilus, actinobacillus, cardiobacterium, eikenella, kingella


common organisms in IV drug users with endocarditis

*staph aureus
*streptococcus, enterococcus
*gram (-)


common organisms with prosthetic valve endocarditis

*staph epidermidis, staph aureus
*gram (-)


empiric tx of endocarditis

vanco and gent, see specific valve type


indications for surgery in endocarditis

*persistent positive blood cultures
*moderate to severe CHF due to valve dysfunction
*recurrent emboli

*myocardial or valve ring abscess (heart block)
*large vegetation >10mm
*fungal or brucella endocarditis
*relapse of prosthetic valve endocarditis p optimal treatment


catheter related Intravascular infection prevention

*chlorhexidine for skin decontamination
*antibiotic coated catheter
*catheter care teams
*no need to routinely replace central catheters


diagnosis of catheter related intravascular infections

*isolate pathogen from peripheral blood culture AND either blood culture specimen from central line or culture of catheter tip


treatment of catheter related intravascular infections

*vanco + gent or 3rd gen cephalosporin
*remove catheter if: severe sepsis, suppurative thrombophlebitis, endocarditis, osteomyelitis, tunnel infection or infections due to: s. aureus, gram (-), fungus.


staph. aureus bacteremia

treat for 2 week if TEE (-), 4 weeks if +


empiric tx of bacterial meningitis with nondiagnostic gram stain

age 3 months to age 60:ceftriaxone + vancomycin

age > 60: ampicillin + ceftriaxone + vanco

* ceftriaxone or cefotaxime for both above


tx bacterial meningitis based on gram stain

*gram (+) cocci: vanco + ceftiaxone or cefotaxime
*gram (-) cocci: ceftriaxone or cefotaxime
*gram (+) bacilli: amp + gent
*gram (-) bacilli: ceftriaxone or cefotaxime or ceftazidime + gent


prophylaxis for meningococcal meningitis

* household contacts, day care contacts
*others with prolonged contact >8 hours in close proximity (3 feet) in the week before onset of patient symptoms

*any one exposed to patients oral secretions
*rifampin 600mg BID X 2days
*meningococcal vaccine to household contacts


predisposing conditions for brain abscess

*otitis media,mastoiditis, sinusitis
*pyogenic infections in chest or other body sites


brain abscess clinical features

headache, fever, focal neurological deficit


brain abscess dx & tx

Dx: MRI-ring enhancing lesion,stereotactic needle aspiration for gram stain and culture
Tx empiric: *head trauma or neurosurg-vanco + ceftiaxone, *hematogenous-vanco and flagyl, *oral focus-flagyl + PCN G, *ear or sinus-flagyl and ceftriaxone


clinical presentation of TB

*primary-infiltrates middle/lower lungs w ipsilateral hilar adenopathy
*reactivation- upper lobe infiltr, freq w cavitation
*extra pulm-l. nodes, pleura, bone,joints, GU, CNS


Dx of TB

*latent infection-tuberculin skin test
-interferon gamma release assay-no cross react w BCG-more specific than tuberculin skin test

*active TB-imaging, AFB smear & culture, histopath of bx sample, NAA-provide dx in 2 days,


Tx of TB

INH + Rifampin + PZA + ethambutol X 2 months then
INH + Rifampin X 4 more months


latent TB testing-PPD, positive if >/+ 5mm in:

*HIV +
recent contact with an active case
CXR consistent with old TB


PPD >/= 10mm positive in:

*IVDU,alcoholic, homeless, medically underserved (low income)
*immigrant(<5yrs) from high prevalence area
*has disease assoc with high risk of TB
*health care workers, resident/staff long term care facility
*recent conversion


diseases assoc with high risk of TB

*silicosis, diabetes, CRF, gastrectomy, malnutrition, leukemia, lymphoma, wt loss >10%, jejunoileal bypass, cancer of head or neck


indications for TB prophylaxis

*all pt with + ppd
*high risk exposure even if ppd negative:
recent close contact for at least 12 hours w infectious TB within 3 months esp if contact is young child or immunocompronised
*repeat ppd 3 mo after contact ended, if ppd-,stop tx, + cont tx


tx for TB prophylaxis, one of regimens below

*INH for 9 months
*rifampin x 4 months
*INH + rifampin X 3 months


PPD testing in nursing home

*test all admitted to NH,if negative, repeat in 1 week.
*if + (>/= 10mm) INH prophylaxis


Interpretation of ppd test in patient with prior BCG

interpret same way as someone without this exposure if BCG was given > 10 years ago

*interferon-gamma release assays (Quantiferon-TB gold) results are not affected by prior BCG


cystitis : s/s, tx

s/s:dysuris, urgency, freq, suprapubic pain, hematuria (no fever)
Tx: 3 day sulfa, 5 day nitrofurantoin, single dose fosfomycin
*pregnancy: 7 day augm nitrofurantoin, cephalosporin, 3gm single dose fosfomycin



*fever,chills,flank pain
*do gm stain, C&S, U/S bladder,renal
*outpt:cipro/levoflox x 7 days
*inpt-see other-IV levaq,rocephin etc


asymptomatic bacteriuria

*tx only in pregnancy, neutropenia, renal transplant pt, urinary obstruction,and prior to invasive urological procedures


urinary catheter related infections

culture only if symptomatic
*keep urine collection bag below level of bladder best way to prevent urinary infections


acute prostatitis

*fever, chills, lbp or perineal pain, dysuria, freq.,urgency
*edematous tender prostate
bactrim is tx of choice, alt fluoroquinolone. tx 4-6 weeks


chronic prostatitis

*s/s recurrent UTI w isolation of same organism from urine
*prostate NOT tender of enlarged
*culture urine BEFORE & AFTER prostate massage, test for chlamydia
*TX: quinolone for at least 6 weeks, bactrim alternative


recurrent UTI (>3/year) in women

*related to coitus-postcoital prophylaxis
*not related to coitus- daily or 3x/wk tx with TMP or bactrim or nitrofurantoin or cipro etc


Lyme disease
*Borrelia bergdorferi
*spread tick Ixodes species
*must be attached >36 hrs to transmit disease

*stage 1: 3-30days p bite:fever, erythema migrans >5cm w central clearing
S.2:fever fatigue,arthralgia,mult annular lesions, neuro sympt
S.3:arthritis (#1knees),encephalopathy,spenomegaly, gen, adenopathy,acrodermatitis-red violaceous ->sclerotic/atrophic


Dx Lyme disease
*serology: ELISA+ then confirm by western blot
IGM western blot + if 2 of 3 bands +
IGG western blot + if 5 of 10 bands +
*after tx IG titers fall slow and may persist many years

*in prev tx patient, a +IGM titer is not indication to retreat unless typical features are present
*culture of skin lesion
*spirochete DNA by PCR on joint fluid or CSF


Post Lyme disease syndrome

*persistent fatigue, myalgias, arthralgias or cognitive difficulties
*no clinical benefit from further treatment


Tx Lyme disease-erythema migrans
first degree AV block
facial paralysis

doxy 100mg BID or
amox 500mg TID or
cefuroxime 500mg BID
*tx 14-21 days all except tx arthritis for 28 days


tx Lyme disease-neurologic disease
high degree AV block with PR interval >.3s
persistant or recurrent arthritis

*IV ceftriaxone 2gm/day or cefotaxime 2gm every 8 hours for 14-28 days


prophylaxis after tick bite

*doxycycline 200mg single dose within 72 hr of tick removal
*indicated if tick attached >36 hours and is adult or nymphal tick (larvae ticks do not transmit disease)
*prophylaxis reduces risk of acquiring dz by 85%


Rocky Mountain spotted fever
*R. rickettsii
*incubation period 2-14 days
*s/s:fever,headache,myalgias, N/V, macular rash wrists/ankles by day 3-becomes petechial in few days

Dx: confirm immunohistologic exam of skin bx
serology (IFA) positive by 7-10 days
TX: doxy 100mg BID, po or IV, chloramphenicol in pregnancy
*complicaions:hypotension, noncardiac pulm. edema,meningoencephalitis


Ehrlichiosis (Human Granulocytic Anaplasmosis)

*fever,chills,vomiting,diarrhea, confusion,shock
*leukopenia, thrombocytopenia, incr AST/ALT
*peripheral smear: morulae in neutrophils, PCR, IFA
*tx:doxycycline, rifampin in pregnant


*B. microti-NE coast US
*incubation :1-4 wk after bite, 1-9 wk after transfusion
*deer tick-ioxdes scapularis
*severe illness in immunocompromised

*protozoa invades RBCs and produce malaria like illness-fever, HA, myalgia,hepatosplenomegaly, retinal infarct, thrombocytopenia, hemolytic anemia-low haptoglobin
Dx:blood smear-pleomorphic ring forms, do PCR
tx-azitro and atovaquone tx of choice


*hematogenous-long bones, vertebrae-s.aureus, gram-ve
*contiguous infection-tibia,femur,skull, mandible-mixed organisms
*vasc. insufficiency-feet-mixed organisms

DX: best for early dx-MRI or three phase bone scan
plain xrays negative up to 2 weeks
diabetic foot ulcers-probe of ulcer touches bone suggests it
*clavicular osteo-after subclavian vein catheter
*sternoclavicular or sacroiliac bone osteo-think IV drug user


toxic shock syndrome assoc with these organisms



staphylococci toxic shock syndrome causes

*non-menstruating-wound infection, skin & soft tissue infections, infected implants


clinical features of toxic shock syndrome

*diffuse sunburn type rash


tx of osteomyelitis

*remove offending items-tampons, catheters, packing,implant
*IV fluids
*IV vanco and clindamycin +/- immunoglobulin


complications of osteomyelitis

*multi system organ failure


parvovirus B19 infection

*erythema infectiosum (slap cheek appearance)
*aplastic crisis in chronic hemolytic anemias
*red cell aplasia in HIV+
*hydrops fetalis or fetal death


*5 major species of parasite Plasmodium
*transmission-bite of female anopheles mosquito
*P. falciparum, P.vivax, P.ovale,P.malariae, I.knowlesi

Clinical features:
*headache,fatigue,myalgia followed by fever and chills


malarias that cause febrile paroxysms at regular intervals

*P. ovale


severe falciparum malaria often see

*impaired consciousness, seizures
*severe hemolytic anemia
*ARDS,renal failure, pulmonary edema and shock


dx and tx of malaria

*thick and thin smears of blood
tx: chloroquine sensitive- chloroquine or amodiaquine
*P. falciparum-artesunate +/-amodiaquine or atovaquone-proguanil or quinine + doxycycline
*primaquine x 14days-prevents relapse in P. vivax & ovale



*bacillus anthracis-gram+ spore forming rod
*cutaneous or inhalation types


inhalation anthrax

*tx:cipro or doxycycline + clindamycin and/or rifampin X 60days
*s/s:fever,dyspnea,hypoxia,hypotension,hemorrhagic mediastinitis (symmetrical mediastinal widening), pleural effusion


cutaneous anthrax

*ulcer surrounded by non-pitting brawny edema
*tx:cipro po 7-10 days, 60 days if related to bioterrorism-alternte tx-doxy or amox if susceptible


post exposure to antrax prophylaxis

cipro or doxy po for 60 days + vaccine (amox can be used if sensitive)


anthrax vaccine

live attenuated vaccine
*5 dose primary vaccine at day 0, week 4, 6mo,12mo,18mo
*booster -single dose at 1 year interval in persons who remain at risk


typical cellulitis, organism and treatment

gram + cocci
*IV cefaolin,nafcillin, ceftriaxone
*po dicloxacillin,cepphalexin...


tx cellulitis in diabetes and likely organisms

*gram + and - , anerobes
*amp/sulb, clinda & quinolone


organism and tx of buccal cellulitis

*H. influenzae


organism and tx of dog or cat bite cellulitis

*P.multocida, anaerobes, capnocytophagia
*moxifloxacin + clindamycin


organism and tx of human bite celllulitis

*strep, staph, anaerobes, Eikenella
*pcn and cephalosporin


organism and tx of cellulitis from injury in SALT water

*IV doxycycline


organism and tx of cellulitis from injury in FRESH water

*IV cipro or cefazidime and gent


organism and tx of cellulitis from working as butcher, fish/clam handler, veterinarian

*erysipelotrix rhusioparhiae-severe infection or endocarditis
*amox po for mild
*Pen G for severe or endocarditis
*alternate: cipro, cefotaxime, imipenem


community acquired MRSA
*clinical: abscess, necrotizing fascitis, sepsis, pneumonia
*risk factors:gay men,HIV, IVDU,children, athletes in contact sport
*Tx: I&D may be sufficient if abscess

Necrotizing fascitis
*cellulitis w dusky discoloration of skin & vesicles w bluish fluid
*marked pain and tenderness that EXTENDS beyond the erythema
*tx: surg debide, IV amp/sulb plus clindamycin


West Nile virus
*virus initially infects birds (esp crows)>mosquitoes>humans
*s/s: aseptic meningitis, encephalitis, axonal polyneuropathy
*dx:IgM capture enzyme linked immunosorbent assay of CSF or serum

Tx-no vaccine, no antiviral for tx or prophylaxis
*prevention-removing standing water, stay indoors at dusk,dawn, wear protective clothing, insect repellant


dx and tx of influenza

Dx: best-rRT-PCR, the rapid antigen tests IFA antibody tests-help confirm influ but negative test does not exclude the dx
Tx-oseltamivir or zanamivir X 5 days


Dengue Fever
* mosquito of genus Aedes
*incubation 3-14 days
*most asia, americas africa

*s/s:fever, severe HA+retro-orbital pain,muscle pain>severe lumbar pain>"break-bone fever" maculopapular rash, petechiae, purpura, leukopenia, thrombocytopenia
*Dx: IgM antibody + 4-5 days, IgG + 7 days,culture virus or PCR
*Tx: supportive, monitor CBC daily


otitis externa organism and tx

*strep, staph, pseudomonas
*tx: topical antibiotic ear drops


Malignant otitis externa

*usually due to pseudomonas in diabetic
*ear lobe/canal is red,swollen,purulent discharge
*tx: IV antibiotic to cover pseudomonas, debridement


otitis media

*strep pneumoniae, H. influenzae, moraxella
*tx high dose amox, if no response amox/clav or bactrim, cefuroxime, azithromycin


22 y/o male found +HIV on routine testing, asymptomatic and normal exam. Initial assessment?

*CD4 lymphocyte count
*Hep B serology
*PPD skin test
*pneumococcal and H. flu type b vaccines


30 y/o male on tx for acute lymphocytic leukemia is admit for fever, leukocyte count 330.exam-no obvious source of fever. start on ticarcillin, tobra + vanco p bld cultures. after 7 days still fever/chills and bld cultures are negative. CXR -. recommend?

add amphotericin B


24 y/o male w 2 week hx vacation on Long Island, now fever and headache. exam: mild nuchal rigidity and left side facial palsy. diagnosis?

Lyme disease


20 y/o male has girlfriend dx gonorrhea, no symptoms. exam normal, cultures obtained. recommend?

ceftriaxone then doxycycline


24 y/o female w 3 wk malodorous vaginal discharge. exam: homogenous, whitish discharge,smoothly coats vaginal mucosa. Vag pH 5.6, 10% KOH-fishy odor and +clue cells on wet mount. dx & tx

dx bacterial vaginosis
tx oral or vaginal metronidazole or clindamycin


28 y/o bitten by bat. bat not captured. no prior rabies vaccine. recommendaton

*rabies vaccine and rabies immune globulin


28 y/o HIV+ male admit w fever,lethargy, headache, confusion. CT head w contrast is negative. LP: WBC 80-95% lymph,5%neutr.,glucose 20, protein 110. what is likely organism?

cryptococcus neoformans


70y/o male admit w 2 wk hx low fever,weak,noc sweats, arthralgia, LBP. 5 wk ago cystoscopy done for hematuria. T101, ejection murmur aortic area w radiation to carotids. 3 set blood culture + enteococcus. hx severe anaphylaxis to PCN. Tx?

vanco + gent for 4-6 weeks


26 y/o homosexual male admit w fever, dry cough, SOA, for 2 days. T 102, crackles b/l lung bases. WBC 6.5k, hgb 11.5, plt 62k. LDH 400, ABG:7.44/36/60. CXR:b/l infiltrates, sputum:methenamine silver stain +, + pneumocystis carinii cysts. tx?

ceftriaxone and doxycycline


22 y/o female w many sex partners c/o urinary freq and dysuria. UA: leukocytes-many, bacteria negative. Tx?



20y/o sexually active female w fever, dysuria, sorethroat and multiple sex partner hx. exam:mucopurulent cervicitis and pharyngitis. tx?

ceftiaxone IM then doxycycline


16y/o male admit x 6 in past 6 mo c meningococcal meningitis. tx with IV Pen G. What to check to see cause of recurrent meningitis?

serum total hemolytic complement (CH50)


70 y/o to ER w abrupt onset of fever, stiff neck,severe HA, confusion and photophobia. LP-WBC 1800 (95% neutrophils), glucose 18, protein 80. gram stain + lancet shaped gm + cocci in pairs. tx

IV ceftriaxone, vanco and dexamethasone


35 y/o female hx mental confusion, fever, skin rash, diarrhea x 3 days. recent dx breast cancer s/p radical mastectomy w silicone implant 5 days ago. VS: 90/60, Hr 110, T 101, diffuse erythematous rash entire body. bld culture (-).albumin 4.2,ca++7.5, wbc 8.5, hgb 13.5 now recommend?

IV vanco and clindamycin
remove implant


26 y/o male HIV+, fever, marked weak X 5 days. CD4 350 6mo ago and started AZT 500mg daily. Hct 3 mo ago 36%. exam:140/76-100, marked pallor, stool - for blood. Hgb5, MCV 95, WBC 3.5, plt 250K , retic index 1%, CD4 320. CXR neg, bone marrow-red cell aplasia. likely dx?

parvovirus infection


55 y/o male admit w fever,chills,on chemo for abdominal lymphoma and has hickman catheter x 2 weeks. site some erythema and tenderness. no tunneling infection, best tx after blood cultures are obtained?

vanco and gent


19 y/o male with fever, mult skin abscess and hx prior abscess and cervical lymph node enlarged w drainage since childhood, mult tx w abx in past. brother w similar hx. diagnostic test to likely reveal cause?

blood nitroblue tetrazolium test


32 y/o HIV male admit w right side weakness, fever, headache. CT head: 2 ring enhancing lesions. CD4 30. recommend?

tx sulfadiazine and pyrinmethamine. repeat CT in 2 weeks


30 y/o male admit w first episode of endocarditis. small vegetation on tricuspid valve, blood culture +MRSA. appropriate treatment?

2 wk nafcillin and gent


70y/o male w BPH having difficulty urinating. foley cath placement unsuccessful and suprapubic cath is placed. 2 days later fever, chills, gram stain urine gm+ cocci and gm - rods. what antibiotic to use?



40 y/o male fight at party punches several people in the mouth. 2 days later hand pain, knuckle red and swollen. best initial antibiotic tx?

amox/clavulanate (augmentin)


24 y/o male HIV + Ab test. CD4 25, VRDL neg, toxoplasma neg. Hep B serology neg. PPD is 6mm, CXR neg. besides Hep B, pneumococcal, influenza, H. influenza type b vaccines, what else for tx?



47 y/o homeless person admit w active pulmonary TB. started on INH, rifampin, pyrazinamide, ethambutol. one month later shows sensitivity to all drugs and his sputum is now negative for AFB. what to recommend?

discontinue etham and pyrazin. after one month
continue INH and rifampin for 4 more months


20 y/o male presents with acute epididymitis. most common cause?



22 y/o female to ER w 1 day hx high fever, sorethroat, and difficulty swallowing. T102, drooling oral secretions, erythema of tonsils and pharynx. xray neck normal. recommend?

admit ICU
IV ceftriaxone
stat ENT consult for fiberoptic nasopharyngoscopy


22 y/o female w 6 mo hx fatigue, arthralgia, gen aches & pains. tx doxycycline x 21 days for early Lyme disease 1 year ago. western blot: + 2 of 3 bands IgM and 6 of 10 bands + for IgG. what tx now?

no tx


28 y/o IVDU admit fever, right pleuritic CP, cough and hemoptysis exam: engorged neck veins w prominent V waves, rales/rub right lung base. 1/6 holosyst. murmur LLSB incr w inspiration. CXR-mult nodular densities b/l w some cavitation. started Nafcillin &gent,4d later new densities CXR. bld&sputum +MRSA. now what

surgical consult


70 y/o w cellulitis left foot after scratched while walking outside barefoot in her rock garden. not diabetic and no other complaints than skin slightly red without oozing or other changes. afebrile, no hx MRSA. likely dx and tx

dx likely meth sensitive staph aureus
*only cefazolin reliably covers S. aureus


female with 2 day hx of diarrhea, works at petting zoo and other workers have diarrhea. she has some blood in stool and low grade fever.many animals at zoo incl snakes, iguanas,alot more. if her diarrhea is due to bacteria, what is most likely?

salmonella- many reptiles transmitt it


19 y/o from arkansas, studying animal husbandry-cattle, sheep,goats. presents with 3 day hx of fever and swollen inguinal lymph node. also he hunts and in rural woods of there state on freq basis with removal of multiple ticks. one tick bite was at site of new ulceration. likely orgnism?

he has Francisella tularensis

*key words: arkansas, tick bite, lymphadenopathy


38y/o male from rural missouri w 4 day of fever, mild sorethroat,fatigue. he hikes in ozarks, no known tick bites but has seen on his dog. he also swims in local pond with his rash. exam neg except mild hepatosplenomegaly WBC 1.5, 60% lymph, hgb 10, plt 55K best test for dx?

*acute & convalescent antibody titers
Dx is ehrlichiosis
* think in outdoor person in Missouri w fever, fatigue, pancytopenia without significant lymphadenopathy


40 y/o in milwaukee has non bloody diarrhea for 3 days, multiple people w same and health dept reports wide spread similar cases. routine stool cultures on many of these have been negative and stool O&P results are pending. what test is likely positive and give clue to etiology of the outbreak?

*acid-fast stain of the stool
dx-cryptosporidium- is a parasite so wouldnt be seen on stool culture.


60 y/o female with poorly controlled DM has 2 day hx of nasal stuffiness and freq nosebleeds. sinus tender on exam, and when look in nasal cavity you see a small black nectrotic area on the nasal turbinate. what organism would you be most worried about

*Mucor species
* this is with high morbidity and mortality as this organism likes to "grow back" into the brain
* think this in DM not controlled & palatal or sinus disease


20 y/o female had splenectomy in 2000 p MVA. she had pneumococcus and H. influenza vaccines. she has been visiting Massachusetts and develops fever 105, shaking chills, and rigors. she is pale and lab shows severe hemolytic anemia. you suspect a parasite, whats best way to dx her infection?

*thick and thin blood smears
*she has Babesia microti infection.
* see in NE US and presents like malaria. hemolytic anemia is common and is more severe in splenectomized . tx is clindamycin, and quinine or atovaquone and azithromycin


29 y/o female from Brownsville tx had been found to have a liver abscess that is likely due to Entamoeba histolytica. best way to dx?

serology testing is best way to dx amebic liver abscesses


60 y/o female with new dx of herpes zoster, on scapula and several dermatomes involves. she is not immunocompromised and is a RN in outpt clinic. what can you tell her about her zoster infection

*Tsank smear would be positive but this is not HSV
*may return to work with area covered by clothing, as long as not direct contact with immunocompromised people.
*there is no respiratory spread of this form


18 y/o in Lyme conneticut presents with 2 day of fever, cough, runny nose and conjunctivitis. thought was cold as friend had same 2 wk ago. last night got rash started back of neck and spread downward, denies tick bite and not sexually active. exam: maculopapular rash hairline> back, oral mucosa white spots with red base

*dx is measles
*immunize all immunocompetent people born in or after 1957 with a live virus vaccine if cant document 2 prior vaccinations.
* egg allergy is no longer a contraindication to the vaccine
* asymptomatic HIV+ can get the vaccine if needed


35 y/o female has 5 yr old son who 2 wk ago had slapped cheek infection and rash on his extremities. she now has mild rash and arthritis of her hands, most in wrist and PCP joints.

*dx is Parvovirus B19, common in childhood.
*adult rash and arthritis are common, esp in females
*those w hemolytic anemia, esp sickle cell may get aplastic anemia/crisis
*once the rash appears in child they are no longer contagious


25 y/o woman w new dx of HIV. her CD4 is 165. viral load is 100,000copies. she is asymptomatic. what tx do you recommend?

*start antiretrovirals (CD4<200)


50 y/o IVDU presents with fever and new murmur. blood cultures are positive for staph aureus in 4 bottles. whats most common cause of cardiac death in people w her dx?

*congestive heart failure
*she has endocarditis


30 y/o female that works at daycare, comes to ER with stiff neck, fever and severe HA. exposure to usual colds in kids at daycare.exam: meningismus and positive Kernig sign. marked photophobia, no focal neuro signs. what tx?

*she has bacterial meningitis until proven otherwise
*attempt quick lumbar puncture then immed give IV vanco and IV rocephin
*vanco given as there is incr risk of resistant pneumococcus esp in daycare setting


60 y/o alcoholic male visits gulf coast Texas frequently and eats raw oysters and large amts of beer. he rented house on beach and wades out daily to fish in gulf. he presents with 30 minute hx of weakness and passing out. skin lesions on his legs, BP76/20, HR 120 presumed septic shock, likely organism?

*vibrio vulnificus
*look for septic alcoholic male, gulf coast, exposure to oysters, gulf water or both. leg lesions common and look like boils or bullous lesions.


60 y/o on cruise ship for first time, after several days at sea he and many others develop explosive diarrhea. whats likely dx?

Norovirus (aka Norwalk virus)
*infected employee usually infects others, fecal-oral route and is fast spreading.
*self limiting but can get severe dehydration


associated with children and daycare outbreaks of diarrhea



diarrhea assoc with pet exposure, esp puppies



cyclospora is assoc with ingestion of

infected raspberries


18 y/o female with severe swollen left ankle. developed fever that day and bumps on her leg. sexually active and says only w boyfriend who was virgin like her. Menses started yesterday and is normal. exam:marked swollen left ankle w frank arthritis and palpable edema. 2 sm pustules above ankle area. DX?

Neisseria gonorrhoeae
*classic skin lesion, exposure, dz started w menses. also think in young person w arthritis


28 y/o male w chicken pox presents in shock bp 70/50. rash on palms/soles and lower extremities. lab creatinine 3.5,ALT 400, AST 450, PT 16,platelets 80K, mucous membrane changes and diarrhea. blood culture grows what organism likely?

streptococcus pyogenes
*toxic shock syndrome due to group A strep- blood cultures usually positive (with staph aureus-blood cult usually negative)
**hx of chickenpox is classic for group A strep superinfection


21 y/o college student presents with new onset hearing loss gradually over past 2 weeks. 6 mo ago had rash on extremities and mild fever. works daycare, one sex partner of 2 years, monogamous. no tick bites, 2 dogs, lives in Georgia. DX?

*treponema pallidum-neurosyphilis

** young person with hearing loss** think syphilis


36 y/o lives in arkansas, last week getting firewood notices tick embeded in right leg, removes tick, 3 days later has marked irritation and swelling in groin. then has fever and severe malase that night. she puts on poultice of sprouts, cayenne pepper and tasco sauce & no better. exam ulcer area at bite and 3x5inguinal lymph node. t103,poor dentition. Dx?

*endemic to Arkansas, Missouri, Oklahoma
*6 forms:ulcer/glandular (this case), glandular,oropharyngeal, oculoglandular (hunter cleaning game), pneumonia, typoidal(bacteremia without gland involvement)


antibiotic that is effective for gram negative killing even after the drug has fallen below the MIC

*post antibiotic effect" this is why once a day dosing is so effective with the aminoglycosides


45 y/o female w AML on chemo. severe neutropenia has fever of 102. you start initial rule out sepsis work up and want to start antibiotics. you find no focus for her fever. what antibiotics?

ceftazidime-covers gram negative organisms and pseudomonas ( rocephin does not cover pseudomonas reliably!)


#1 cause of bacterial meningitis in the US

strep pneumoniae- 10% are resistant to rocephin so use rocephin and vancomycin


when suspect meningitis and no indication of increased intracranial pressure

do LP if can and immed start rocephin and vanco


antibiotic that should not be used in pregnant woman

cipro-any quinolone and tetracycline are contraindicated in pregnancy


only drug that is effective for influenza B


*it will also be effective some strains inf. A


70 y/o male w chronic renal insuf on chronic hemodialysis 3x week.yesterday developed fever, temp now 101.5, graft site looks fine and no other complaints when he comes for dialysis. exam is unremarkable. blood cultures are takn and at 24 hours are growing what likely organism?

methicillin resistant staph epidermidis- as he has fever but is not that ill in appearance of symptoms. this is common organism infection in pt w indwelling catheters and prosthetic material


3 week old presents to ER with signs of sepsis. what antibiotic?

ampicillin-cover enterococcus, listeria and group B strep
plus cefotaxime to cover gram negative.
*must know how to treat baby with meningitis


a man from Arizona presents with an inguinal lymphadenopathy and fever. he is a hunter and lives in the desert. what is likely dx?

plague-remember arizona


pasteurella is assoc with

cat and dog bites


cat scratch is assoc with

bartonella henselae



is only positive in about 50% of neurosyphilis, so cant rule out with negative VDRL on CSF


38 y/o male w AIDS (CD4 20) presents w fever/chills several days. no antivirals as says they make him sick.he is also very weak and cant walk flight stairs without SOA. exam:hepatosplenomegaly, palatal ulcer. lab:pancytopenia, WBC 1.5, hgb 7, plt 110K whats likely opportunistic infection present?

histoplasma capsulatum
*also this is more likely as he lives in Indiana (Mississippi river valley) is also clue to this


65 y/0 male is at dentist and he notices a black growth in the patients nose and sends him immed to his doctor who notes the painless black ulcer in the nasal septum. DX?

mucormycosis-immed hospital and stat ENT-aggressive debride and antifungals-grows back into brain, poor prognosis


a man from Arizona presents with inguinal adenopathy and fever. he is a hunter and lives in the desert. what is likely dx?



30 y/o lives in Houston and buys fresh produce at local stand. after eating from her selection she develops severe diarrhea as well as her family of 7. she is diagnosed with organism Cyclospora. what is likely source?



27 y/o that travels frequently is asking about going to Southeast Asia for mission trip and wants to know about prophylaxis for various diseases. what should they take for malaria prophylaxis?

*atovaquone/proguanil (Malarone) newer agent thats effective against chloroquine-resistant malaria which is likely in this area.
*primaquine- also taken as Plasmodium ovale/vivax malaria is also in this area. this drug is taken near the end of prophylaxis w malarone


40 y/o male w AML is admitted with fever. WBC is 900 with 10% neutrophils. he is started on cefepime. he continues to have fever, his ANC - absolute neutrophil count-today on hospital day 7 is now 40. what agent should be started now?

*liposomal amphotericin B should be added fro antifungal coverage at 5-7 days of fever and neutropenia.


nurse on the HIV unit is drawing blood on HIV+ patient and accidentally sticks himself with the needle he used to draw the blood. he quickly washes his hands and goes to employee health. what next?

start ZDV,3TC, and lopinavir/ritonavir

*this is high risk exposure, start prophylaxis as soon as possible


30 y/o former IVDU had a prosthetic aortic valve placed 1 month ago. woke yesterday w fever and chills and presents today w fever and no other, exam only shows Janeway lesions. blood cultures drawn, what is likely etiology of his endocarditis?

staph epidermidis, methicillin resistant **this is likely organism less than 2 months from his surgery. he will likely need surgery, mortality is high, tx vanco, gent and rifampin


40 y/o from Rhode Island presents with isolated Bell's palsy that started yesterday . she hikes in area but no known tick bite. no other symptoms. dx?

Lyme disease -classic presentation
*most dont have a history of tick bite or erythema migrans
*tx is doxycycline


25 y/o develops diarrhea after traveling to a water park in Georgia. ate hamburgers and played in kiddy pool. diarrhea bloody this morning and has fever, some abd cramping. exam normal except grossly positive heme on rectal exam. cultures reveal enterohemorrhagic E.coli, what tx?

no antibiotic this is E. coli 0157:H7 use of antibiotics increases the risk of hemolytic uremic syndrome


80 y/o male NH resident has been hosp three times in past 3 years for urosepsis. he has chronic indwelling catheter due to incontinence after prostate surgery. he now has T103, flank pain, chills and appears ill.

vanco and ceftazidime to cover gram negative and MRSA and pseudomonas


70 y/o female visiting countryside in Colorado , takes off shoes for walk in field and steps on dirty nail. she hobbles to sit down but steps in cow manure, then her dog licks the injured foot.. she goes to ER for tetanus immunization, she has had >3 tetanus in past, most recent 4 yrs ago. what do u recommend?

no tetanus needed today.
*dirty wound, 3 and most recent


woman complains of head hurting, not being herself for 3 hours. temp 102 and says has drooping of her left face and now has double vision. what tx?

*acute meningitis and has focal neurologic signs-so give IV antibiotics, do CT scan before LP to determine if safe to do LP as she has focal neuro symptoms must do CT first but dont wait on giving antibiotic


40 y/o female on chemo for AML has a one day hx intermittent fever 103 and chills, exam normal except mucositis, pallor and tachycardia. lab: WBC 0.6 without neutrophils or bands. CXR and UA are normal, blood cultures and urine cultures are taken. what antibiotic?

*vanco and cefepime (febrile neutropenic pt need to cover pseudomonas and gram negatives very well)


guidelines for when or when not to use vancomycin

*No vanco for intial treatment unless:

Use vanco for initial tx if:
*hypotension/ cardiovascular compromise
*suspected IV catheter-related infection
*known colonization with MRSA or resistant pneumococcus


28 y/o steps on dirty nail in cow pasture and pet iguana licks wound. last Td 6 years ago. had all her immunizations as a child. what does she need today?

Tdap only


18 y/o presents with hx stepping on nail that went thru his tennis shoe 4 days ago. last night got severe pain and swelling and unable to bear weight on his foot. admitted and culture taken in the operating room gram stain shows gram negative rods. likely organism?

*pseudomonas aeruginosa- **tennis shoe puncture
he has pseudomonas osteomyelitis


infections that are a contraindication for breast feeding

*active, untreated TB
*maternal HIV infection


neutropenia occurs in:
*bone marrow transplant
*metastasis to bone marrow

*overwhelming sepsis, gram (+):s.aureus, s.epi, streptococcus; gram (-): pseudomonas and other
*fungi impt pathogens:candida, aspergillus, fusarium


fungal infection in neutropenia thats especially deadly



febile neutropenia exam

*they dont have enough neutrophils so they may lack localizing signs of inflammation
*upper airway mucosa, teeth, eye and rectum impt to exam
*any rash or skin ulcer/swelling is potentially impt


antifungal NOT used in empiric tx of febrile neutropenia thought due to fungus


*it is ineffective against aspergillus


if pt w pulmonary presentation and could be invasive pulmonary aspergillosis, tx with

Liposomal amphotericin B or voriconazole


Humoral deficiencies-Inherited-usually present childhood. dx with measure of IgG, IgA, IgM

*x linked agammaglobulinemia
*common variable immunodeficiency
*IgA deficiency


Humoral deficiency-Acquired



IgA deficiency

*#1 inherited deficiency
*most no symptoms, but if symptoms they usually present :

*recurrent sinopulmonary disease from:encapsulated organism, recurrent giardia, food and respiratory allergies
*often have autoimmune dz: Hashimoto, celiac dz, SLE, pernicious anemia, rheumatoid arthritis


**female with IgA deficiency know these important facts

*they can have a false + UCG
*if given blood transfusion they are at very increased risk of ANAPHYLAXIS-they have anti-IgA antibody and if transfuse IgA they get rxn. -not contraindicated but avoid if able
*IVIG is contraindicated for same reason as blood transfusion


if see adult with recurent giardiasis x 3 think

IgA deficiency


complement deficiency puts person at increased risk of

*infection-recur sinopulmonary infection +/- otitis media with encapsulated bacteria: *pneumococcus, H. influenza, neisseria
*auto immune disease-esp development of SLE at an early age
*C2 is most common


C3 deficiency is assoc with

severe infections with pneumococcus and H influenza from infancy


C5-C9 complement deficiency is assoc with

**recurrent Neisseria infections: N. gonococcus, N. meningococcus


screening for complement deficiency

**deficiency causes UNDETECTABLE CH50 titer, so if see that, look for each individual complement level. start with C2 as it is most common


solid organ transplantation

*can reactivate infections they had previously controlled with their immune system
*3 time periods post transplant and type of greatest risk:

*Month 1: infection from donor and nosocomial infection
*Months 2-6:immunosuppresent rx takes effect-opportunistic infections
*Month >6:community acquired infections


PCN initially developed for WWII wounds and had good gram + skin flora coverage,but staph rapidly developed resistance by penicillinase that destroys the drug with this beta lactamase enzyme. to deal with this :

semi synthetic PCN was produced for these organisms that are labeled "methicillin sensitive" today we use drugs nafcillin and dicloxacillin.
*these drugs can cause tubulointerstitial nephritis-fever, rash, eosinophilia


only PCN effective against Pseudomonas aeruginosa and acinetobacter

*Zosyn-piperacillin & tazo


only drugs effective for SERIOUS infections due to MRSA and MRSE



1st generation cephalosporins

*cover most staph, strep
*NO anaerobic coverage


2nd generation cephalosporins


not used much as most now use 3rd gen


3rd generation cephalosporin



great pneumococcus drugs
*use in combo w vanco for tx pneumococcal meningitis
*DO NOT COVER: staph or anaerobes
*only ceftazidime covers pseudomonas in this class of drugs


vancomycin effective against

*most gram +


vancomycin Red Man Syndrome

*tachycardia, flushing,occassionally see angioedema, pruritis
*prevent by slowing infusion rate or pretreat with antihistamines (Not treated with H2 blockers)


2nd generation quinolones-Cipro

*covers mostly aerobic gm - rods:E.coli, pseudomonas, salmonella, shigella, campylobacter,yersinia enterocolitica
*prophylaxis adult, non pregnant, close contacts N. Meningitis
*alternative in TB treatment
*NOT good tx of pneumonia


Levofloxacin (3rd generation quinolone) "Respiratory "

preferred drug in tx of: community acquired pneumonia
H. influenza


4th generation quinolones


good aerobic, anaerobic gram - rod coverage


only drug effective against all schistosoma



staph aureus often etiology of

*bacteremia IVDU and dialysis patient
*TSS-toxic shock syndr
*scalded skin syndrome
*furuncle, carbunkle



*nasal colonization difficult to eradicate-intranasal or under nails, tx bactroban oint and wash hibiclens

MRSA bacteremia-first line is vancomycin and also drug of choice on boards for skin and soft tissue infections as well as invasive MRSA


TSS-toxic shock syndrome, usual organisms

*staph- ** blood cultures usually negative
*strep pyogenes/strep- blood cultures usually positive



*red skin


TSS associated

*menses and use of tampons
*any postop TSS- must remove any implanted device immediately
*strep pyogenes TSS-usually from progressive skin infection and especially post op and with CHICKEN POX


staph epi

*coagulase negative staph
*almost always meth resistant
*#1 cause of catheter related bacteremia and post op w implant or device
*tx vanco +/- rifampin


streptococcus pneumoniae
*need functioning spleen to make antibodies to defend against this encapsulated organism and H. influenza
*sepsis can be rapidly fatal=flu s/s, purpura, DIC

both strep pneum and H influenzae seen more commonly in:
*splenectomized patients
*sickle cell, CML, multiple myeloma,agammaglobulinemia
*very young and old patients


pneumococcal pneumonia

*almost all beta lactams achieve high conc. in the lungs
*tx: PCN or 3rd gen. cephalosporin


empiric tx of pneumococcal meningitis

vanco and 3rd gen cephalosporin


bacteria assoc with 30% cases of colon neoplasm

*strep bovis


suspect this organism if get sepsis or endocarditis after genitourinary manipulation


*tx-gent plus one of these:vanco, ampicillin, PCN G



*assoc w decr cellular immunity-AIDS, lymphoma, leukemia
neonates, elderly, pregnancy

**resistant to ALL cephalosporins
Tx: mild to moderate-PCN or amp
serious-add aminoglycoside
Listeria meningitis-aminoglycoside and very high dose PCN or ampicillin


Corynebacterium diphtheriae

*diptheria-upper respiratory infection
**gray-white pharyngeal membrane, sorethroat, low fever <101
*tx: diphtheria antitoxin always given with #1 choice emycin or alternate PCN


Bacillus anthracis

*contaminated hides, wool, terrorism
*large gram (+) RODS
*not contageous


3 clinical manifestations of anthrax

1. cutaneous -95%, PAINLESS papules>vesicles>ulcer>black eschar with nonpitting induration
2. inhalation-pulmonic (woolsorters disease) **dx clue: mediastinal widening.
3.pharyngeal and GI: eat undercooked contam. meat


anthrax treatment

*quinolone-tx and prophylaxis in terrorism

*usually also sensitive to : PCN,Emcin, TCN


B. cereus

*assoc with FRIED RICE
*gastroenteritis symptoms, self limiting usually, if serious tx with vancomycin
*contact lens wearer occ see after traumatic eye injury



alpha toxin

strict anaerobic gram + ROD


clostridium difficile

antibiotic assoc colitis


clostridium botulism

**most potent known
*blocks presynaptic acetylcholine release


clostridium perfringens

one of most common food poisonings ,24 hour onset diarrhea
*contaminated meat or gravy


those with sepsis from this organism often have an associated GI MALIGNANCY

clostridium septicum


clostridium tetani

*acute antibiotic tx is now flagyl
*give tetanus toxoid and immunoglobulin


Nisseria gonorrhoeae

*gram (-) diplococci


Neisseria meningitidis (meningococcus)

*gram (-) cocci
*people w complement deficiency are prone
*s/s:fever, hypotension,DIC, purpuritic lesions-diffuse


N Meningitis-treat empirically

*3rd gen cephalosporin and vanco for meningitis
*chloramphenicol is used if PCN allergy
*with tx, mortality is 10%


N meningitis-prophylaxis

*to close contacts - to eradicate the carrier state in anterior nasopharynx
*live in house with patient, contacts at daycare, exposed to pts oral secretions-ie person thats intubated
*Not all healthcare workers w patient


N meningitis rx for prophylaxis:
*non pregnant adult-fluoroquinolone- Cipro not used in MN or North Dakota due to some resistance in those states
*child and non pregnant adult-rifampin

*ceftriaxone-pregnant and child < age 15
*pts with the disease tx w PCN also need to be tx w prophylaxis drug to eradicate the carrier state


Pseudomonas aeruginosa
*gram (-) rod- single flagellum
*assoc w nail puncture tennis shoe, IVDU, acute or chronic OM, otitis externa, severe in diabetes

*erthyma gangrenosum-round indurated black lesions w cental ulceration, see in pseudomonas bacteremia
*hot tub rash-self limiting


Pseudomonas treatment

*serious infection-tx with 2 antipseudomonal rx's until susceptibilities are back

Cipro , aminoglycoside, Pcn and beta lactam, cabapenems, aztreonam, cefepime, cefbzidime



*gram - bacilli-motile
*common cause diarrhea from food-chicken, milk,eggs; animals-baby chickens, iguanas, baby turtles


salmonella typhi
*non motile and encapsulated
*causes typhoid fever
*contaminated food, milk , water
*adults-are more likely carriers it seeds the gallstones

*leukopenia, "rose spots" on trunk 1 week after fever starts looks like 2-3mm angiomas
*typhoid vaccine > age 2 if outside tourist areas in asia, africa and Latin America
*tx:quinolone, 3rd gen ceph., amp, bactrim, chloramphenical


Yersinia pestis
*gram (-) coccobacillus
Plague-reservoir wild rodeents transmit by fleas or direct contact with amimal ie when skin them-high mortality

*bubonic plague-large localized "buboes" that suppurates,if not tx leads to sepsis and death.
*pneumonic form-rapid transmit via cough to bystanders
**like tularemia w adenopathy after hunting but location is desert SW. tx:streptomycin or TCN or quinolone


Legionella pneumonia
*aerobic gram (-) bacilllus
*culture media:charcoal yeast extract
*contained in water, transmission #1 aspiration, mult others

*multisystem dz is clue to dx:diarrhea, headache, confusion, pneumonia
*tx: azithromycin or quinolone
if severe add rifampin


Francisella tularensis

*small gram (-) pleomorphic bacillus
*tularemia "rabbit fever"
*dx:hx, s/s, serologic test

*transmission: tick & blood sucking flies
*location : Oklahoma, Missouri, Arkansas
*s/s:sudden fever,chill,malagia, arthralgia, then irreg. ulcer at site,regional adenitis,necrosis
*Tx: streptomycin or gent..TCN if not severely ill


Bartonella henselae
*cat scratch disease

Tx:rifampin plus gent or azithromycin
treat lymphadenitis due to this w azith.


Helicobactor pylori

*gram (-) spiral flagellated bacillus
*causes gastritis and PUD
*is a risk factor for adenocarcinoma of the stomach


Rickettsia rickettsii

*Rocky mountain spotted fever
*gram (-) coccobacillus
*classic s/s:

*rash-distal extremities progresses, maculopapular>petechial
*fever, headache,arthralgias, some diarrhea/abd pain
*recent hx tick exposure
*dx:immunofluor. stain on bx skin lesion
*tx:empiric-TCN,doxycycline or chloramphenicol


Q fever-Coxiella burnetii
*transmission_inhale aerosol released by infected animals-see in slaughter house workers

*tx: usually self limited, if severe-doxycycline


Ehrlichia-erhlichiosis "spotless" Rocky Mountain fever
*areas-2 types: Missouri & arkansas, other type in NE & upper Midwest

s/s: NO RASH
*fever, HA,leukopenia, may have thrombocytopenia
**if hx of tick bite & pancytopenia -think erhlichiosis!
Tx: doxy/TCN


Mycobacteria marinum
*fish tank " bacillus
*non healing skin ulcers in people w fish tanks

*often looks like "string" of lesions along the lymph channel
*tx: ethambutol + rifampin or clarithromycin + rifampin


Treponema pallidum-syphilis
*Primary-3-40days occurs and lasts 2-6 wks and resolves, painless chancre w regional lymphadenopathy,female often no s/s
*secondary-2 months after primary and gen.lymphadenopathy, constitutional s/s,mucosal +/- skin lesions "great imitator"

*lesions palms + soles "nickle + dime" lesions. s/s resolve 3-12 weeks and goes latent
*Tertiary-occurs 1-10 years or more after initial untreated infection
causes GUMMAS-soft granulomas , can cause aortitis, CNS dz


Neurosyphilis can present as :
*tabes dorsalis:foot slap, wide-based gait
*general PARESIS:
P=defect personality
A=reduced affect

R=abnormal reflexes
E=eyes-Agyll-Robertson pupil
S=defect sensorium
I=defect intellect
S=defect speech


Argyll Robertson pupil

*miotic and irregular
**constricts normally to accommodation but NOT to LIGHT


Dx syphilis
*serologic tests
(antibodies to B burgdorfi-lyme-cross react and may cause false positive MHA or FTA results, but no false VDRL or RPR)

*VDRL, RPR-after tx these usually go back to negative
*Treponemal (MHA-TP + FTA-ABS) -these stay + for life
*20-30% of patients will be negative for either test in primary dz
*nearly 100% positive either test in 2ndary or 3tertiary syphilis


Tx syphilis

all (except neurosyphilis) is tx with Benzathine PCN G or doxycycline, neurosyphilis is tx only with PCN G IV 10-14 days


Tx of pregnant and newborn with syphilis

only with PCN!

if allergic to PCN-desensitize them then tx w PCN



*spirochete disease
*Clue-contact with dog or rat urine

*dx: after 10 days of illness-culture urine and blood for anti-leptospira IgM
*tx: PCN or doxycycline


Lyme disease
*Ixodes scapularis tick, most transmitted nymph stage fetal infection and death

*stage 1: 90% serology will be negative, if see erythema migrans, just treat-dont need to confirm with testing
*no prophylaxis for just outdoor activities
*if hx outdoor in endemic area or tick bites -do serology-high false (+)ELISA so need to confirm with Western Blot


Tx Lyme disease

*early dz and Bell palsy: doxy or amox for 10-21 days
*isolated lyme arthritis: doxy or amox for 28 days

*cardiac or neuro disease from lyme: ceftriaxone or PCN G IV x 21 days
*no role long term antibiotic tx in "chronic lyme dz"



*blood culture showing candida is NEVER a contaminant
*TX: in non neutropenic patient-fluconazole
in neutropenic patient-casofungin- also use if resistant



*old pigeon droppings
*usually self limiting and mild symptoms

*crypto.pneumonia-cavitary lesions common and peripheral "cannon ball" skin lesions
*disseminated and crypto meningitis- any type of immunocompromised patient


Cryptococcal Meningitis
**LP findings :**CSF opening pressure>200mm Hg-pt at high risk blindness if pressure not handled properly- repeat LP daily, some need shunts

Dx: serum or CSF cryptococal antigen test
Tx: ampho B plus flucytosine when stable change to fluconazole


*only see in immunocompromised host
*mold spores in soil SW and northern Mexico "valley fever"
*once inhale, cocci convert to yeast

*flu like self limiting illness, arthralgia, erythema multiforme and or erythema nodosum
*often presents with pulmonary "coin lesions"
**think in pt w sarcoid like s/s and from Arizona
*Tx: usually none, if severe-amphoB


*Mississippi and Ohio river valleys
*bat & bird droppings
*healthy pt-mild flu like and self limited

*immunocompromised-disseminated >blood and bone marrow>rapid sepsis and multiorgan s/s-tx ampho B


Zygomycosis (prev. called mucormycosis)
**strong assoc w diabete and hemochromatosis

**invasive rhinocerebral mucormycosis-starts necrotic nose or paranasal sinuses and extends intracranially-poor px!!
Tx-debride and ampho B


Toxoplasma gondii
*cat feces
*pregnant female-can cause fetal mental retardation and necrotizing chorioretinitis-mom usually asymptomatic . fetus incr risk in 3rd trimester

*ocular toxo-retinal lesions "yellow-white cotton patches" (disseminated candida see "white cotton wool patches")
*tx: pyrimethamine & sulfonamide x 3 weeks


primaquine- malaria tx-can cause hemolytic anenia if

pt has G6PD deficiency so must screen for this before its use


disease assoc w "maltese cross" in RBC pear shapes



Giardia lamblia
*see in : campers, travelers, daycare, HIV/gay men, IgA deficiency, hypogammaglobulinemia
*infects duodenum, 75% asymptomatic

*chronic dz:flatulence, soft stools, sulfuric belching
*dx;3 fresh stool or giardia antigen on 1 stool, string test
*tx: flagyl or tinidazole


Tryoabisinuasus brucei

*sleeping sickness-Africa
*tsetse fly


illness assoc with eating bear meat-Canada

Trichinella spiralis larvae "trichinosis"


Only helminth organism that replicates in the body

Strongyloides stercoralis


Toxocara canis

Host-dogs-transmit by soil contaminated with dog feces and is ingested
*causes visceral larva migrans


think this if see new onset seizure of Mexican immigrant or household contact

Taenia solium-pork tapeworm
*tx: albendazole, seizure med , steroids
*egg of tapeworm in food ingested(animal or human feces )-eggs hatch and oncospheres into blood and cause cysticerci in CNS & eyes-cysts do nothing until organism dies



*infects the BLADDER=> urine symptoms

Schistosoma-acute s/s:
*fever, lymphadenopathy, diarrhea, hepatosplenomegaly, marked eosinophilia
**most serious complications: CIRRHOSIS W ESOPH. VARICES
*TX: one day of praziquantel (all flukes)


clues to herpes encephalitis

*temporal lobe seizures
*abnormal behavior
*Tx: IV acyclovir


Recommendations for pregnant woman exposed to chicken pox

**give Vari ZIG-zoster immune globulin within 4 days of exposure
**NEVER VARIVAX-this is live virus=birth defect esp wks 8-20 gestation


varicella-zoster virus tx that will decrease the incidence of post herpetic neuralgia

*famciclovir & valacyclovir



post herpetic/zoster pain control

*TCA, gabapentin, lidocaine - some efficacy
*narcotics-effective and under used
*capsaicin cream- helpful AFTER lesions have healed


Epstein Barr virus-EBV
*incubation 1-2 months
*s/s:pharyngitis/tonsillitis, fever, lymphadenopathy, abnl liver fxn,50% splenomegaly

*chronic fatigue assoc has never been proven due to EBV
*assoc w: nasopharyngeal carcinoma, Burkitt lymphoma
*most with mono develop macular rash if given ampicillin


Measles - Rubeola
*incubation 10 days
*s/s: 3 C's: cough,coryza,conjunctivitis
*Koplik spots-whitish spots on erythematous base on buccal mucosa BEFORE onset of skin rash

*skin rash-starts hairline and spreads downward-lasts approx 5 days, and resolves in same way it appears


*bats, racoon, skunk, fox,dog, cat,ferret...
*NOT in squirrels
*1-3 months after exposure: viral syndrome>encephalitis, Guillian Barre mimic or neuropathic pain +/- sensorimotor deficits

*encephalopathy-classic rabies symptoms:hydrophobia,choking,delirium
*dx:eval of several specimens:saliva,skin,CSF, brain biopsy


Rabies preventative vaccine indicated for

*cave explorers
*animal control workers
*anyone handles bats


Tx potentially rabid animal

*rabies immune globulin-inject around wound
*contact CDC for need of post exposure vaccine
*person previously vaccinated-only need booster after bite, NOY immune globulin


*winter-early spring most common

*unilateral or bilateral parotitis
*aseptic meningitis or encephalitis
*20% post puberty males-epididymoorcititis-usualy unilateral orchitis-sterility is rare


another cause of enlarged parotids

Bulemia-due to frequent vomiting


Parvovirus B19
*Fifth disease-"slap cheeks"-erythema infectiosum
*aplastic anemia- in AIDS pt or person with chronic hemolytic anemia-bone marrow shows giant pronormoblasts

Dx:acute and convalescent IgG & IgM titers-look for 4 fold rise



*hantavirus pulmonary syndrome:starts w severe myalgia,fever.headache,cough and quickly progresses>ARDS>death in 50%

*primary reservoir: deer mouse
*east coast and SE-main reservoir-cotton rat
*inhale excreta,saliva or break in skin.NO person to person. NO rash. CLUE: young person w severe hemorrhagic pneumonia w decreased platelets and increased hematocrit


HPV viruses assoc w cervical cancer

HPV 16, 18, 31


Creutzfeldt Jakob disease
*prion disease-lack nucleic acid
*most common prion disease
*incubation -18 months

*see dementia-severe and myoclonus
*death approx 5 months
*no treatment


infection assoc with marijuana use



Subacute diffuse encephalitis in AIDS patient

common and is caused directly by HIV virus[


native valve endocarditis
*more common left side heart
*usually on regurgitant AV valve

#1 staph aureus-more likely to die and develop emboli with this

#2 viridans strep


Prosthetic valve endocarditis

*early (2 mo)-often invades the annulus and surgery is required-most due to staph epidermidis


classic stigmata of infective endocarditis:
*conjunctival hemorrhages
*petechiae #1 skin finding
*splinter hemorrhages

*Janeway lesions-blanching,painless,reddish lesions on hand/feet
*Osler nodes-painful,purple lesions on fingers & toes
*Roth spots-retinal hemorrhages


PID-pelvic inflammatory disease
*causes: N. gonorrhea, chlamydia, normal vaginal flora
*risk of infertility, also can get Fitz-Hugh-Curtis syndr:perihepatitis

*outpatient: rocephin 250mg IM then doxy 100mg and flagyl 500mg both BID X 14 days
*inpatient: cefotetan& doxy or clinda & gent
*retest for cure of chlamydia in 3 weeks


Gonococcemia-disseminated gonorrhea

s/s: fever, arthralgia, occ oligoarthritis (knee or ankle common)
tenosynovitis-asymmetric, muscle aches and rash w few lesionsare papular w hemorrhage into the papules

*dx: swab all orifices
tx: 3rd gen cephalosporin and azithromycin 1gm or doxycycline



*prepuberty boys and men > age 35: usually E. coli

*sexually active male < age 35: usually chlamydia, C. trachomatis


Bacterial vaginosis
*miilky discharge, foul smelling, "fishy" and Clue cells
*tx flagyl po or intravaginal

**pregnant: NO CREAMS
treat flagyl 500mg bid x 7 days or 250 mg tid x 7 days
or clindamycin 300mg bid x 7 days
**tx is ORAL due to higher risk of preterm labor and delivery with intravaginal creams***


vaginal candida tx in pregnant

only tx with azole cream for 7 days

*if recurrent candida consider HIV testing


Trichomonas vaginalis
*men usually asymptomatic
*7-30 day incubation
*frothy yellow-green discharge,odor, strawberry cervix,vaginal erythema

*flagellated organism on wet mount
*vaginal pH >5.0
*tx: flagyl 2 gm single dose or tinidazole 2 gm po dose


*urine culture no longer needed if young female w acute UTI
*if no complicating factors, pyuria alone is indication to tx
*U/S kidneys only if persistant fever or clinical symptoms after 48-72hrs of antibiotics

Tx: routine UTI bactrim x 3 days
uncomplicated pyelonephritis-cipro or levaquin 5-10 days
complicated pyelo. -see abx 2 given IV


UTI tx in pregnancy
*treat asymptomatic bacteriuria-1/3 go to pyelonephritis
*always admit and tx pregnant patient with pyelonephritis and treat as if complicated pyelo

as above


otitis externa - swimmers ear
*tx with antibiotic ear drops

malignant otitis externa-canal and subcutaneous tissues involved
*pseudomonas common
*suspect in diabetic, immunocompromised patient
*tx: early cipro, late IV


usual impetigo bacteria

strep pyogenes
staph aureus


*staph aureus
*pseudomonas think if IVDU especially if vertebrae or pelvic
*salmonella in sickle cell patient
*blood culture + in approx 2/3

*negative pyrophosphate bone scan excludes osteomyelitis
*spinal osteomyelitis-needle biopsy is first diagnostic procedure
*must remove necrotic bone before a chronic osteomyelitis can be cured with antibiotic


prosthetic joint infection
*staph epi most common
*1% get infected
*usually chronic

*xrays-bony changes
*do joint aspiration for C & S


nosocomial (hospital acquired) pneumonia
*usually gram (-) bacteria, if not gm(-) then staph aureus
*highest mortality rate

*if ICU acquired, likely transmission from HANDS of ICU worker


nosocomial catheter related infection

3types, all can cause bacteremia/fungicemia

*septic thrombophlebitis


nosocomial secondary endocarditis
*more in patient w catheters that extend into the heart
*IV lines become infected after about 3 days
*metal needles less likely than plastic to become infected
*IV catheter infection usually staph epi or aureus

*remove catheter
*antibiotic x 2 weeks - vanco
*if Hickman/Broviac and gram (+) bacteremia-no need to remove it and tx 2-4 wks, use vanco until cultures back for sensitivity


LIVE vaccines-NOT given to pregnant & immunocompromised

*yellow fever
*intranasal influenza


KILLED vaccines -safe preg and immunocompromised
*Td, Tdap

*trivalent influenza



if born AFTER 1956-2 doses needed


Meningococcal vaccine
*give conjugated vaccine if 56
*except for college students, booster vaccine after 5 years if continue to be in high risk group:

*asplenic or complement deficiency
*freshman in college dorm
*military recruits
*travel to meningitis belt-sub sahara Africa
*lab workers who work w neisseria