1. September 18, 2013
Anna Kaltsas MD MS
Assistant Attending Physician
Infectious Diseases Service

2.  Consults x7535
 Green team: attending only
service
◦ Solid tumors, Ortho, GU,
Neurology
 Blue team: attendings + ID
fellows
◦ Leukemia, lymphoma, ICU,
Pediatrics
 Pharmacists – Antibiotic
Approval bpr 1100
 Infection control – x7814
 MSKCC guidelines on
intranet (“Reference manuals
and tutorials”)

3.  Draw blood cultures first!!!
◦ Don’t forget UA, urine culture, CXR, C. difficile, LP if
indicated
◦ Work up for other source: ultrasound r/o DVT
◦ Not all fevers need empiric antibiotics!
 Consider contact/respiratory isolation needs
 Previous culture results
 Allergies
 What types of bacteria?
◦ Anatomic site
 Oral/GI: mixed, anaerobes
 Skin: GPC, ?viral
 Lung: atypical, GPC;
 HAP: GNR, anaerobes (aspiration)
 Urine: GNR

4.  Penicillin
◦ Most commonly reported
medication allergy – 10% of all
patients
◦ Anaphylaxis: 1-4 episodes/10,000
doses
◦ 85-90% found not to be truly
allergic (IgE mediated)
 History of PCN “allergy”: only 0.17-
8.4% will react to cephalosporins
 PCN allergy by skin test: 2% will react
to cephalosporins
 Imipenem: 0-11% cross reactive
 Aztreonam, quinolones: 0 cross
reactivity
 Vancomycin/red man syndrome:
◦ histamine-mediated; rate
dependent infusion reaction.
◦ Not a true allergy!
Angioedema.
http://www.wellsphere.com/chronic-
pain-article/i-am-a-professional-
patient-part-two/624311
Drug rash.
http://www.riversideonline.com/source/ima
ges/image_popup/r7_drugrash.jpg

5.  250,000 cases
annually/80,000 in ICU
 High hospital cost, patient
morbidity, 12-25% mortality
 Suspect if tunnel/exit site
erythematous, has discharge,
or pt has fever without a
source.
 CVC + PICC > tunneled
catheters and implanted ports
 Sources for infection:
◦ Skin flora (extraluminal)
◦ Contamination from hubs/access
ports (intraluminal)
◦ Hematogenous/Infusion related
http://www.executivehm.com/article/Improve-
CRBSI-Prevention-Target-Intraluminal-Risks/
http://www.moffitt.org/moffittapps/ccj/v3n5/
dept6.html

6.  Gram stain with GPC: Vancomycin
◦ Recent history of VRE: Linezolid
 Gram stain with GNR: Zosyn or Cefepime
◦ Narrow to cephalosporin or oral quinolone when sensitivities are
back and repeat cultures are negative.
 MSSA: oxacillin, nafcillin, cefazolin superior to
Vancomycin.
 Yeast/Candida: Micafungin
◦ Pull line
◦ Optho consult (rule out endophthalmitis), TEE
 Repeat blood cultures daily until negative x72 hours.
◦ If repeated cultures positive after 72 hours of appropriate
antibiotics, consider pulling line.
◦ If patient is sick/septic, consider pulling line.
 Ok to replace central line/PICC when blood cultures clear
x72 hours.

7. O’Grady NP et al. Guidelines for the
prevention of intravascular catheter-
related infections. CID 2011:52.
Mermel LA et al. Clinical practice
guidelines for the diagnosis and
management of intravascular catheter-
related infections: 2009 update by the
Infectious Diseases Society of
America. CID 2009:49

8.  Skin flora are common
contaminants
 Coagulase-negative staphylococci
(S. epidermidis)
 C. jeikeium, Bacillus, diptheroids
(gram positive bacilli)
 Suspect contamination if single
culture from one lumen positive.
◦ All peripheral cx and other lumens
negative
◦ Pt/catheter looks well and has other
source for fever.
◦ Blood cx were drawn before
antibiotics.
 S. aureus and Candida spp are
almost never contaminants!
Scanning EM; Bacteria
underneath human toenail.
http://resident-alien.blogspot.com/2007/07/humans-
wear-diverse-wardrobe-of-skin.html

9.  UTI = most common nosocomial infection.
◦ 10-30% of catheterized patients develop bacteriuria.
 10-25% of those with bacteriuria develop UTIs
 Up to 80% of patients with cutaneous diversion of
urine through conduits develop bacteriuria and
chronic colonization.
◦ Stomal mucus, nephrostomy tubes, stents, catheters allow
for biofilm formation and propagation of bacterial growth.
◦ UTI/pyelonephritis can occur from stasis of urine, reflux of
urine, self catheterization techniques.
◦ PCN/stent obstruction or dislodgement:
 Temporary blockage of the flow of (colonized urine) can result
in ascending infection, fever, bacteremia.
 Symptoms: fever >38oC, suprapubic/CVA tenderness, SIRS
 Diagnosis: urine cx >105 cfu/mL OR urine cx >103 cfu/mL with
pyuria on UA + above symptoms – on repeat specimen AFTER
changing foley
Warren J. Catheter-associated urinary tract infections.
Infect Dis Clin; 1997. 11(3):609-22.
Bruce AW et al. Bacterial adherence in the human ileal
conduit: a morphological and bacteriological study. J Urol.
1984 Jul;132(1):184-8.

10.  UAs are unreliable in patients with
foley catheters, PCNs, ileal conduits.
◦ Change foley and repeat UA/urine culture
 Ceftazidime, Cefepime, Zosyn
empirically
◦ Narrow once antibiotic sensitivities are
known
◦ Target initial antibiotics to past urine
culture results.
◦ High rate of GNR resistance to quinolones!
 Enterococcus, CN staph, Candida are
often contaminants (perineal flora,
colonization of catheters).
 Asymptomatic bacteriuria does not
have to be treated except in
pregnancy or before GU procedures.
 In patients with GU hardware –
persistent fever/UTI sx despite
appropriate antibiotics is an indication
to replace stent/PCN!
http://www.theurologygroup.cc/images/Bladde
Replacement-7.gif

11.  8-15 cases/1,000 persons per year
 Highest in winter months,
extremes of age
 S. pneumoniae most common
world-wide
 Suspect if: cough (productive),
fever, pleuritic chest pain, dyspnea
 Following viral illness
 High risk: >65, smokers, recent
chemo, neutropenia, intubated,
HIV/AIDS;
 Post-obstructive PNA: lung
mass/met obstructing bronchus
 Aspiration pneumonia:
◦ head and neck surgery
◦ speech/swallowing difficulties
◦ mental status changes
◦ Tube feeds/aspiration event! Right middle lobe pneumonia.
http://www.med-
ed.virginia.edu/courses/rad/cxr/pathology3ch
est.html

12.  Does the patient need
respiratory isolation (viral,
TB)?
 Work up:
◦ Chest Xray/CT Chest (non
contrast)
◦ Sputum cultures/deep tracheal
cultures if intubated
◦ Blood cultures
◦ If CAP: Legionella urine antigen,
S. pneumoniae urine antigen
◦ Viral nasal swab (automatic
droplet precautions)
◦ To rule out TB: sputum for AFB
x2, 24 hours apart
Gram positive diplococci on sputum gram stain.
http://drugster.info/img/ail/268_269_3.jpg

13.  Inpatient, non ICU, CAP:
◦ Ceftriaxone 1gm IV daily x7d + Azithromycin 500
mg IV/po daily x5d
 Aspiration PNA:
◦ Unasyn or Ceftriaxone + Flagyl
 ICU, Hospital-acquired PNA, nursing home
resident:
◦ Zosyn 4.5 gm IV Q6h + Cefepime 2 gm IV Q12h
+/- Azithromycin 500 mg IV daily +/- Vancomycin
IV x5-7 days
◦ PCN allergy: Aztreonam + Flagyl; Imipenem

14.  Infection extending beyond the
hollow viscus into previously
sterile peritoneal space.
◦ Cholecystitis, diverticulitis, bowel
anastomosis/surgery, typhlitis,
bowel obstruction…
 >1000 species of gut bacteria;
more than 10 times the number
of cells in the human body!
◦ Abscess formation
◦ Peritonitis
 Second most common cause of
infectious mortality in ICUs.
 Appendicitis alone: 300,000
patients/year
Solomkin et al. Diagnosis and Management of Complicated
Intraabdominal Infections in Adults and Children: Guidelines by the
Surgical Infection Society and the Infectious Disease Society of
America. CID 2010:50
Free air.
http://www.wjgnet.com/1007-9327/full/v14/i24/WJG-
14-3922-g001.htm

15.  Diagnosis: Physical exam, CT scan (po and IV contrast),
ultrasound (gall bladder).
◦ Signs of sepsis may be minimal in elderly or those on high-dose
steroids.
 Draw blood cultures
 Start appropriate antibiotics
◦ Cover GI flora: GNR, anaerobes, enterococcus, +/- Pseudomonas,
+/- Candida
◦ Cover organisms previously isolated in abscess drainages
◦ Culturing fluid in JP drains is low yield
 Surgical or IR consult
◦ Mainstay of treatment for intra-abdominal abscess is surgical
drainage + antibiotics!
◦ Biliary stent change
◦ Treat for 10-14 days post drainage or until abscess resolved on
follow up imaging.

16.  Unasyn, Zosyn, and Imipenem have anaerobic
coverage!
 Spontaneous Bacterial Peritonitis
◦ Ceftriaxone 2gm IV daily
 Bowel Perforation, Intraperitoneal abscess
◦ Include Pseudomonas coverage!
◦ Zosyn or Cefepime/Flagyl OR Cipro/Flagyl +/- Vancomycin
 Diverticulitis
◦ Unasyn Or Cipro/Flagyl
 Neutropenic Enterocolitis (Typhlitis)
◦ Include Pseudomonas coverage!
◦ Zosyn + Amikacin
 Gall bladder (biliary sepsis, cholangitis, cholecystitis)
◦ Unasyn OR Ceftriaxone/Flagyl OR Ciprofloxacin/Flagyl

17.  Gram positive anaerobic
bacillus; toxin producing.
 Most common cause of
antibiotic-associated diarrhea in
the hospital.
◦ Diarrhea; colitis; toxic megacolon;
sepsis
 20-30% recurrence rate; 1-2.5%
overall mortality; 25% mortality
in elderly or very infirm.
 Cepheid GeneXpert PCR
platform 96%
sensitivity/specificity
 Do not use as “test of cure” –
false positives
http://www.google.com/imgres?imgurl=http://www.health-
writings.com/img/uf/pseudomembranous-colitis-
symptoms/imgCdifficile4.jpg&imgrefurl

18.  Initial episode, mild/moderate:
WBC <15, Cr <1.5:
◦ Flagyl 500 mg po Q8h
 Initial episode, moderate or
severe, sepsis: WBC >15, Cr
>1.5
◦ Vancomycin 125 mg po Q6h
 Unable to take po, ileus, toxic
megacolon:
 Flagyl 500 mg IV Q8h + Vancomycin
po/PR
 Second episode:
 Same as initial therapy x14 days
 Third or more episodes:
◦ Consider ID consult; prolonged
Vancomycin po taper
Toxic megacolon.
http://cueflash.com/decks/Pathology_Chapter_17_and_19_I
mages*

19.  Commonly seen at MSK
 Risk factors include
lymphadenectomies (axillary
LND – upper extremity
lymphedema; pelvic LND – lower
extremities), diabetes, PVD,
DVTs, chemotherapy, radiation
 Beware venous stasis dermatitis!
 Abscesses require I&D
 Culture anything that’s draining
 Blood cultures low yield unless
systemically ill
 Antibiotics: Ancef 1gm IV q8h
◦ Vancomycin if PCN allergic or high
suspicion for MRSA
 po options:
◦ Skin flora: Keflex, Cefadroxil
◦ MRSA: Clindamycin, Doxycycline,
Bactrim; Linezolid
Cellulitis in setting of
lymphedema.
http://www.acols.com/lymphedematoday/
Left leg cellulitis
http://odlarmed.com/wp-
content/uploads/2009/01/cellulitis_left_leg.jpg

20.  Women with lymphedema have
10 times the risk of cellulitis
 (Brewer et al, Risk factor analysis for breast cellulitis complicating breast
conservation therapy; Clin Infect Dis. (2000) 31 (3): 654-659.)
 Skin flora, ?gram
negatives in seromas
 Ancef -> po Cefadroxil
 Vancomycin if PCN allergic
 Consider adding
quinolone for gram
negative coverage if no
improvement, evidence for
infected seroma
 Repeated infections or
history of S. aureus: may
need to remove
expander/implant.
Cellulitis with tissue expander.
http://www.realself.com/question/tissue-expander-
infection

21.  “flesh eating disease;” can spread
through tissue at a rate of 3
cm/hour
 25% mortality
 Needs IMMEDIATE surgical
debridement
 Polymicrobial; Group A strep
 Bacteria introduced by minor
trauma
◦ Minor erythema, “pain out of
proportion to exam”
◦ Deep tissue infection, sepsis, shock
 Fournier’s gangrene: NF of pelvic
area
 ABX: Unasyn or Zosyn +
Vancomycin +/- Clindamycin
http://www.jyi.org/features/ft.php?id=463

22.  Mortality 8-10% per episode
◦ Higher with liquid tumors, advanced age, multiple co-
morbidities
◦ Higher mortality: Gram negative bacteremia > gram
positive bacteremia
 “GI” or “oral” source – mucositis, translocation of
bacteria across mucosa
 Invasive fungal infections with prolonged neutropenia
 Work up: Physical exam, CBC, chemistry, CXR or CT
Chest, blood cultures x2, UA/urine culture
 MSKCC guidelines:
◦ Zosyn or Cefepime; OR Aztreonam + Vancomycin
◦ After 72 hours: add Vancomycin
◦ After 5-7 days add Ambisome
◦ Await count recovery!!
Kuderer et al. Mortality, morbidity, and
cost associated with febrile
neutropenia in adult cancer patients.
Cancer; 2006. 106(10):2258.