ID Flashcards
What is staph epi associated with
Catheters
Prosthetic valves
Dialysis
Bacteria covered by amoxicillin
H. influenzae E. coli Listeria Proteus Salmonella
What are the B-lactams
PCNs
Cephs
Carbapenems
Aztreonam
What PCNs the best initial therapy for
Otitis media Dental infection/Endocarditis PPx Lyme limited to rash, joints, CN VII UTI in pregnancy L. monocytogenes Enterococci
What are Ox/clox/diclox/naf used for
Skin infections
Staph Endocarditis/Meningitis/Bacteremia
Sensitive osteomylitis and septic arthritis
Anti-pseudomonal PCNs are best initial therapy for
Bacteremia
Febrile neutropenia
Cholecystitis
HAVP
Ascending cholangitis
Pyelonephritis
What do all cephalosporins cover
Grp A, B, C strep Viridans E. coli Klebsiella P. mirabilis
What is resistant to all cephalosporins
Listeria
MRSA
Entercoccus
Rash to PCN then use
Cephalosporin
Anaphylaxis to PCN then use
Non-beta lactam ABX
Cephalosporin covering MRSA
Ceftaroline
AE Cefotetan, Cefoxitin
Deplete prothrombin
Increase bleeding risk
AE Ceftriaxone
Inadequate biliary metabolism
What doesn’t ertapenem cover
Pseudomonas
What is Aztreonam for
G- bacilli including pseudomonas
AE quinolones
Bone growth abnormalities
Tendonitis (achilles)
What is Doxy for
Chlamydia
Richettsia
Lyme
What is TMP/SMX for
Uncomplicated cystitis
PCP
First choice mouth and GI abscess
Beta lactam/Beta-lactamase combinations
Best initial therapy staph and strep
Ox/Clox/Diclox/Naf
Cephazolin, Cephalexin (PCN rash)
Fluoroquinolones
Macrolides (PCN anaphylaxis)
What does clindamycin cover
Anaerobes, staph, strep
What doesn’t clindamycin cover
Mycoplasma
Legionella
Best Rx MRSA
Vanco Linezolid Dapto Tigecycline Ceftaroline
AE Linezolid
Reversible BM toxicity
AE Daptomycin
Elevated CPK
Coverage for Tigecycline
G-
Anaerobes
MRSA
Minor MRSA skin infections are treated with
TMP/SMX
Clindamycin
Doxy
Linezolid
Anaerobe coverage above diaphragm
Clindamycin = #1 PCN Carbapenems Cefoxitin Cefotetan
Anaerobe coverage in ABD/GI
Metro
Beta lactam/Beta-lactamase combinations
G- bacilli coverage
Quinolones Aminoglycosides Carbapenems Pipercillin, Ticarcillin Aztreonam Cephalosporines 3rd/4th
All 80-90% effective
Main G- bacilli (Anaerobes)
E. coli Klebsiella Proteus Pseudomonas Enterobacter Citrobacter Morganella Serratia
What do all CNS infections present with
HA
Fever
N/V
All can give seizures
Most likely Dx stiff neck, photophobia, meningismus
Meningitis
Most likely Dx confusion w/ HA/Fever
Encephalitis
Most likely Dx focal neuro signs w/ HA/Fever
Abscess
MC organism in meningitis
S. pneumo
MC organism in meningitis in adolescents
N. meningitides
First step in suspected meningitis pt w/ confusion/focal deficits
CT before LP
Most accurate test meningitis
CSF Cx via LP
Most sensitive test meningitis
CSF protein
Best initial test for meningitis
LP
What says whether or not to treat in meningitis
CSF cell count
Organism in meningitis w/ AIDS
Cryptococcus
Organism in meningitis w/ hiker, target rash
Lyme
Organism in meningitis w/ hiker moving rash
RMSF
Organism in meningitis w/ pulm TB
TB
Organism in meningitis w/ adolescent, petechial rash
Neisseria
Rx cryptococcal meningitis
Amphoteracin B until Ag decreases
Fluconazole for life if T cells don’t rise
Rx Lyme meningitis
Ceftriaxone
Rx RMSF meningitis
Doxy
Rx TB meningitis
Rifampin
Isoniazid
Pyrazinamide
Ethambutol
Plus steroids
Defining CSF feature bacterial meningitis
Cell count in 1000s w/ neutrophils
Defining CSF feature TB meningitis
Tons of protein
Neonatal meningitis etiology
S. galactiae
Neurosurg meningitis etiology
S. aureus
When is Head CT better than LP for initial test
Possibility of space-occupying lesion causing herniation
What sx mean do head CT before LP in meningitis
Papilledema
Seizures
Focal neuro deficits
Confusion
Meningitis management when there is contraindication to LP
ABX immediately
When do you do bacterial Ag detection test
When ABX is given before LP so Cx may be falsely -ve
Dx test for TB meningitis
Acid fast stain and Cx on 3 high volume LPs
Dx test for Lyme and Rickettsia meningitis
Serology
ELISA
Western blot
PCR
Dx test for Cryptococcal meningitis
India ink
Crypt Ag
Dx test for Viral meningitis
Dx of exclusion
No Rx
Best initial Rx bacterial meningitis
Ceftriaxone
Vanco
Steroids
When to add ampicillin to bacterial meningitis regimen
Immunocompromised for Listeria
Risk factors for Listeria meningitis
Elderly Neonates Immunicompromised - Alcoholism - Steroids - HIV/AIDS - Pregnancy
Most important step in N. meningitidis management
Respiratory Isolation
Close contact ABX for N. meningitidis
Rifampin
Cipro
Ceftriaxone
What is “close contact”
Dorms
Barracks
No spleen
Steroids
Most common neuro defect in untreated bacterial meningitis
CN VIII deficit (deafness)
MCC encephalitis
Herpes simplex
Best initial test for encephalitis
Head CT
Most accurate test for herpes encephalitis
PCR
Best initial test genital herpes
Tzanck
Most accurate test genital herpes
Viral Cx
Best initial therapy for herpes encephalitis
Acyclovir
Acyclovir resistant herpes encephalitis Rx
Foscarnet
Steps to therapy of ring-enhancing brain abscess in HIV+
Pyramithamine + Sulfadiazine for toxo
No response = lymphoma
Bx
Steps to therapy of ring-enhancing brain abscess in HIV-
Brain Bx
Presentation of otitis media
Redness
Immobility
Bulging
Decreased light reflex
Most sensitive physical finding for otitis media
Immobility
Most accurate Dx test for otitis media
Tympanocentesis
- Esp. recurrences or non-responsive to ABX
Best initial therapy for otitis media
Amoxicillin
Alternate therapy for otitis media if amox fails
Amox/clavulanate
Azithro, clarithro
Cefuroxime, Loracarbef
Levo, Gemi, Moxi - NOT in children
Organisms in sinusitis
S. pneumo - 40%
H. influenzae - 30%
M. cattharalis - 20%
Most accurate test for sinusitis Dx
Bx
When to do sinusitis Bx
Recurring
No response to different empiric
First line therapy for sinusitis
Amox/Clav
Doxy
TMP/SMX
Best initial therapy for otitis and sinusitis
Amoxicillin
Presentation of Pharyngitis
Pain on swallowing
Enlarged LNs
Exudate
Fever
Important negatives in pharyngitis
Cough
Hoarseness
MC organism in pharyngitis
Strep (Group A beta hemolytic)
Best initial test for strep pharyngitis
Rapid strep test
This is equivalent to +ve pharyngeal Cx
What can untreated strep pharyngitis lead to
Rheumatic fever and Glomerulonephritis
Small pharyngeal vesicles or ulcers
HSV or herpangina
Membranous exudates on pharynx
Diptheria
Vincent angina
EBV
Best initial therapy for strep pharyngitis
PCN or Amox
Rx strep pharyngitis for PCN allergy
Cephalexin if rash
Clinda or Macrolide if anaphylaxis
Criteria for Influenzae vaccination
> 50 Chronic lung/heart disease Preg 2nd/3rd trimester Nursing home Health-care worker Immunosuppressed
Presentation of influenzae
Arthralgias/Myalgias Cough Fever HA/sore throat N/V/D
Most important next step within 48hrs of influenza presentation
Nasopharyngeal swab to detect Ag
Rx within 48hrs of Sx
Oseltamivir
Zanamivir
Rx more than 48hrs of Sx
Sx treatment only
1 cause of blood/WBCs in stool
Campylibacter
Causes of infectious diarrhea with blood/WBCs in stool
Salmonella Campylobacter E. coli 0157:H7 Shigella V. parahemolyticus V. vulnificus Yersinia C. diff Entamoeba hystolytica
Causes of HUS
E. coli 0157:H7
Shigella
Associations with yersinia
Hemochromatosis
Blood transfusions
Association with campylobacter
GBS
Association with V. parahemolyticus
Shellfish
Cruise ships
Association with V. vulnificus
Shellfish
Liver disease
Skin lesions
Features of HUS
Hemolysis
↑ Cr
↓ Platelets
Causes of infectious diarrhea without blood/WBCs in stool
Viral Giardia Cryptosporidiosis B. cereus Staph
Association with giardia
Camping/hiking
Unfiltered fresh water
Looks like fat malabsorption
Association with cryptosporidiosis
AIDS CD4
Association with B. cereus and staph
Vomitting
Best Dx test for giardia
1 stool ELISA Ag
Features of scromboid
Most rapid onset
Wheezing, flushing, rash
Found in fish
Treat with antihistamines
Rx infectious diarrhea
Mild - oral fluid replacement
Severe - Fluid replacement and oral ABX (quinolones)
What is “severe” diarrhea
Hypotension Tachy Fever ABD pain Bloody diarrhea Metab acidosis
Rx giardia diarrhea
Metro
Tinidazile
Rx cryptosporidiosis diarrhea
Treat underlying AIDS
Nitazoxanide
Rx Viral diarrhea
Fluid support
Rx B. cereus diarrhea
Fluid support
Rx protocol for C. diff
Metro
Get’s better → Gets again → Metro again
Doesn’t get better → Vanco
Who is at worst risk for Hep E
Pregnant
Route of transmission Hep B, C, D
Sex
Blood
Perinatal
Route of transmission of Hep A, E
Food and water
Dx tests for hepatitis
Increased direct bili
Increased ALT/AST ratio
Increased ALP
Rare complication of acute hepatitis
Aplastic anemia
MCC liver transplant
Hep C (not for long)
Most likely correlated with increased mortality in Hep
Elevated PT
Best Dx test Hep A, C, D, E
IgM - acute
IgG - resolution
How is disease activity in Hep C assessed
PCR for RNA level
First serum abnormality in Hep B
sAg
Which serum value is associated with viral replication in Hep B
eAg
ie. can transmit
Which serum value is associated with resolution of active Hep B infection
No sAg
Best indication for need for Rx w/antivirals for chronic Hep B
eAg
Best indication that pregnant mother will transmit Hep B to child
eAg
Serology in Hep B vaccinated
sAb
Serology in Hep B window
cAb (IgM then IgG)
Serology in old/resolved Hep B
cAb
sAb
Serology in Acute or chronic Hep B
sAg
eAg (+/- in chronic)
cAb (IgM or IgG)
Rate of conversion of Acute to Chronic Hep B
In 10% of pts
Rx acute Hep C
IFN
Ribavirin
Boceprevir or Telaprevir
What is chronic Hep B
sAg present for > 6mos
Rx eAg w/ elevated DNA pol
One of: Entecavir Adefovir Lamivudine Telbivudine IFN Tenofovir
AE IFN
Arthralgia/myalgia
Leukopenia and thrombocytopenia
Depression and flu-like Sx
Goal of chronic hep Rx
Reduce DNA pol to undetectable
Conver eAg to eAb
Why do liver Bx in hep B or C
Presence of fibrosis is strong indication to start therapy
Fibrosis progresses to cirrhosis in acute viral replication
AE ribavirin
Red cell anemia
Goal of therapy in chronic Hep C
Undetectable VL
Difference between cystitis and urethritis
Cystitis doesn’t have discharge
Both have frequency, urgency, burning
Best initial test for urethritis
Swab for Gram stain
Most accurate test for urethritis
Urethral Cx, DNA probe or nucleic acid amplification for gonorrhea and chlamydia
Best drug combo for urethritis
Cefixime (gonorrhea)
Azithromycin (chlamydia)
Alternative drug combo for urethritis
Ceftriaxone (gonorrhea)
Doxy (chlamydia)
Presentation of cervicitis
Discharge
Strawberry cervix
Testing and treatment identical to urethritis
PID presentation
Lower ABD tenderness
Cervical motion tenderness
Leukocytosis
Fever
First thing to do in pt w/ cervical motion tenderness
Check for ectopic pregnancy
Dx test in PID
Cervical swab for Cx
DNA probe
Nucleic acid amplification
Most accurate test for PID
Laparoscopy (only if Dx unclear)
Features of disseminated gonorrhea
Tenosynovitis
Polyarticular
Petechial lesions
Inpatient PID Rx
Cefoxitin or Cefotetan w/ Doxy
Outpatient PID Rx
Ceftriaxone and Doxy (+/- metro)
Inpatient PID PCN anaphylaxis Rx
Clinda and Genta and Doxy
Outpatient PID PCN anaphylaxis Rx
Levo and Metro
Common feature of all ulcerative genital lesions
Inguinal lymphadenopathy
Most likely STD with painless ulcer
Syphilis
Most likely STD with single painful ulcer
Chancroid
Most likely STD with tender LNs and pus
Lymphogranuloma venereum
Most likely STD with vesciles before multiple painful ulcers
Herpes simplex
Best initial test Syphilis (most sensitive)
Dark field microscopy for spirochetes
Secondary Dx test in syphilis
VDRL/RPR
Confirmatory (best) test for Syphilis
FTA/MHA-TP
Dx test for chancroid
Stain and Cx
Dx test for Lymphogranuloma venereum
Complement fixation titers in blood
Nucleic acid amplification on swab
Best initial test for herpes simplex
Tzanck
Most accurate test for herpes simplex
Viral Cx
Next step in pt with painful genital vesicles
Immediate Rx oral acyclovir
No need for Dx test
Important points about granulareum inguinale
Bx
Sulfa drugs
Donovan body
Appearance of primary syphilis
Heaped-up indurated edges
Painless adenopathy
Secondary syphilis features
Rash on palms and soles
Alopecia areata
Mucous patches
Condyloma lata
Pityriasis rosacea features
Herald patch
Not palms and soles
VDRL/RPR negative
Most common manifestations of tertiary syphilis
Neuro
- Meningovascular
- Tabes dorsalis
- Paresis
- Argyl-Robertson pupil
Rare manifestations of tertiary syphilis
Aortitis
Gummas
Things that cause false positive VDRL/RPR
Infection Older IVDU AIDS Malaria APL Endocarditis
Rx primary and secondary syphilis
IM PCN
Oral doxy if allergic
Rx tertiary syphilis
IV PCN
Desensitize if allergic
Rx Jarish-Herxheimer rxn
Aspirin
Antipyretics
Rx neurosyphilis in pregnancy
PCN
Desensitize if allergic
What causes condyloma acuminata
Papillomavirus
Dx condyloma acuminata
Visual
Rx condyloma acuminata
Remove
- Cryotherapy (liquid nitrogen)
- Surgery
- Melt (podophyllin or trichloroacetic acid)
- Imiquimod (sloughs off)
Important points about Pediculosis (crabs)
On hair-bearing areas
Itchy
Visible
Rx Permethrin
Important points about Scabies
Found in web spaces, elbows, genitals, nipples
Burrows visible
Scrape and magnify
Rx Permethrin
Rx widespread (crusted)/or keratotic w/ ivermectin
MCC UTI
E. coli
Best initial therapy for pyelo
Quinolones
When do you image in UTI
Men
Reccurent/failure to respond
ie. Foreign body/obstruction (complicated)
Best initial test for cystitis
U/A w/ >10 WBCs
Most accurate test for cystitis
Urine Cx
When do you look for bacteria in urine
Pregnancy
Rx uncomplicated cystitis
Nitrofurantoin or Fosfomycin
TMP/SMX x3 days if uncomplicated, 7 if it is complicated
Cipro in resistant areas
Cefixime
Rx male cystitis
TMP/SMX 10-14 days
Rx Pregnant cystitis
Nitrofurantoin/Amox/Macrodantin for 10-14 days
What is pyelonephritis
Dysuria with:
- Flank/CVA tenderness
- Fever
- ABD pain from inflamed kidney
First like Rx pyelonephritis
Ceftriaxone
What works for pyelo
G- bacilli drugs
- Ertapenem
- Ampi + Genta (emperic)
- Cipro oral for outpatient
Most accurate Dx test for pyelo
Bx
What is acute prostatitis
Dysuria w/:
- Perineal pain
- Tender prostate
Increase yield for urine cx in acute prostatitis
Prostate massage
Long term therapy for chronic prostatitis
TMP/SMX 6-8wks
Rx acute prostatitis
Same as pyelo G- bacilli drugs - Ertapenem - Ampi + Genta (emperic) - Cipro oral for outpatient
How to know if there’s a pyelonephric abscess
Pyelo doesn’t resolve
Persistent fever after 5-7 days of therapy
Most important step in pyelonephric abscess
Drainage then Cx
When to suspect endocarditis
Fever + Murmur
MCC death in untreated endocarditis
Infectious glomerulonephritis
Best initial test for endocarditis
Blood Cx
Other options to Dx endocarditis
TTE
TEE
Next step after finding strep bovis endocarditis
Colonoscopy
Diagnosing Cx neg endocarditis
Oscillating vegetation on echo 3 minor criteria - Fever - Risk factor - Embolic phenomena
Best empiric Rx endocarditis
Vanco and Genta
How long are endocarditis Rx regimens
4 weeks
How do you treat resistant endocarditis
Add aminoglycoside and extend to 6 weeks
Rx viridans endocarditis
Ceftriaxone or PCN
Rx S. aureus endocarditis
Ox/Naf or cefazoline
Rx Staph epi or resistant staph endocarditis
Vanco
Rx enterococci endocarditis
Ampi and genta
When is surgery the answer for endocarditis
CHF!! Prosthetic valves Fungal Abscess AV block Recurrent emboli while on ABX
What is added to regimen with prosthetic valve endocarditis with staph
Rifampin
MCC culture neg endocarditis
Coxiella
Also bartonella
Other Cx neg endocarditis organisms
HACEK
Rx for HACEK endocarditis
Ceftriaxone
Who gets endocarditis prophylaxis
Significant cardiac defect
AND
Risk of bacteremia (bloody surgery)
What is given for endocarditis PPx
Amox 1hr prior
Allergy - Clinda, azithro or clarithro
GI procedure - Amp or Vanco
Cause of Lyme disease
Borrelia burgdorferi
Most common manifestation of Lyme
Rash and fever
MC joint complication of Lyme
Knee
MC heart complication of Lyme
AV block
MC neuro complication of lyme
CN VII palsy (can be B/L)
Vector for Lyme
Ixodes scapularis (deer tick)
Prevalence of presentation in untreated Lyme
90% rash
60% joint
10-15% neuro
4-10% heart
Dx Lyme
Nothing if lesion is typical
Straight to Rx
Dx lyme for other manifestations w/o rash
Serology
IgM, IgG, ELISA, Western blot, PCR
Rx Lyme w/ just rash or w/ joint/CN VII
Doxy
Amox or Cefuroxime
Rx cardiac or other neuro in Lyme
IV ceftriaxone
Rx ASx tick bite
NOTHING
:Lyme PPx
1 dose doxy within 72hrs
Who gets lyme PPx
Ixodes scapularis clearly identified
Tick attached > 24-48hrs
Engorged tick
Endemic area
How long does CD4 depletion take before Sx
5-10yrs
Viral load is inversely proportional to
Rate at which T cells drop
ONLY routine PPx in AIDS
CD4
PPx in AIDS regardless of T cell count
PPD >5mm = INH 9 mos
Flu and Pneumococcal vaccines
Does kissing transmit HIV
NO
Infections CD4 200-500
Candidiasis Zoster Kaposi TB HSV PN
Infections CD4
PCP
Infections CD4
Toxo
Infections CD4
MAC
CMV
- Ganciclovir
- Foscarnet
First manifestation of HIV Rx failure
Rising VL
Best initial test for HIV
ELISA
Confirmed with Western blot
Dx HIV infected infants
PCR or viral Cx
When to start HIV Rx
CD4 100,000
Opportunistic infection
Best initial Rx HIV
Emtricitabine + Tenofovir + Efavirenz
HIV regimen skeleton
2 NRTI + 1 PI or efavirenz
Meds for multi-class drug resistance
Entry inhibitors - Enfuvirtide - Maraviroc Integrase inhibitor -Raltegravir
What does Ritonavir boost
Darunavir
Atazanavir
Postexposure PPx (including bites)
4 weeks combination therapy
What predics abacavir hypersensitivity
HLA B5701
AE Zidovudine
Anemia
AE Stavudine and Didanosine
Peripheral neuropathy
Pancreatitis
AE Abacavir
Hypersensitivity
Steven-Johnson
AE Protease inhibitors
Hyperlipidemia
Hyperglycemia
AE Indinavir
Nephrolithiasis
AE Tenofovir
Renal insufficiency
Perinatal PPx HIV+ already on antiretrovirals
Continue regimen
Perinatal PPx HIV+ not on antiretrovirals
Give antiretrovirals as if they weren’t pregnant
Perinatal PPx HIV+ High CD4, Low VL
Antiretrovirals for entire pregnancy
Stop after delivery
Perinatal PPx HIV+ Low CD4, High VL
Antiretrovirals for entire pregnancy
Continue after delivery
Only retroviral contraindicated in pregnancy
Efavirenz
When to do C-section in HIV mother
CD4 1000
What intrapartum antiretroviral is given to every HIV+ pregnant pt
Zidovudine
