Infectious Disease Part II

Question 1

Causes of cellulitis

Answer 1

Group A strep
Hemophilus typically facial in adults or in children
Underlying disease
Bite-related
-Cat: Pasturella multocida
-Pig: Group A strep
-Dog: Polymicrobial
Fresh water
-Aeromonas
Salt water
-Vibrio vulnificus
-Vibrio cholera

Question 2

Abscess

Answer 2

Spontaneous (non-traumatic and even some traumatic)
-Staph almost all the time traumatic
-Puncture through a sneaker- Gm neg, esp pseudomonas
Liver abscess (streptococci, gm neg bacilli)
Muscle abscess (pyomyositis): staph and others
Brain abscess (anaerobes, strep, staph, proteus)

Question 3

I & D colors

Answer 3

Blue-vein
Red-arteries
Yellow-nerves

Question 4

Classical gas gangrene organism

Answer 4

Clostridium perfringens

Question 5

Diabetic infection organism

Answer 5

Half are due to S. aureus

Question 6

Bacteremia

Answer 6

Fevers
Chills
Toxemia (looks sick but not always)
Shock
Cold extremities (vasoconstriction)

Question 7

Systemic Inflammatory Response Syndrome (SIRS) criteria

Answer 7

Greater than or equal to 2 meets SIRS definition
Temp >38 degrees C (100.4 degrees F) or <36 degrees C (96.8 degrees F)
HR >90
RR >20 or PaCO2 <32 mm Hg
WBC >12,000, <4,000, or >10% bands

Question 8

Cystitis

Answer 8

Bladder infection
Children, women, and elderly men- clinical presentations
Children- fevers, pyuria
Infant boy

Question 9

Urethritis

Answer 9

Veneral and non-venereal urethritis
Gonococcus- typically purulent d/c, urethral, cervical
Chlamydia- serous (clear) d/c
Ureaplasma
Mycoplasma

Question 10

Common cause of UTI

Answer 10

E. coli

Question 11

Bone and joint infection organism

Answer 11

Spontaneous
S. aureus older age group
Hemophilus in children
Gonococcus (sexually active with risk factors)
Many other causes

Question 12

Joint fluid analysis

Answer 12

Bacterial

• Large number of WBCs
• Typically bacteria seen on Gm stain
• Glucose in synovial fluid is low
• No crystals seen

Question 13

Which abx inhibit cell wall synthesis?

Answer 13

PCNs
Cephalosporins
Carbapenems

Question 14

Which abx inhibit protein synthesis?

Answer 14

Aminoglycosides
Tetracyclines
Macrolides
Lincomycins
Daptomycin
Linezolid

Question 15

Cefoxitin

Answer 15

Useful as a preventive antibiotic for intra-abdominal surgery

Question 16

3rd gen cephalosporins

Answer 16

Broader spectrum Gm neg rods and PCN R pneumococcus
-Ceftriaxone
Adds pseudomonas aeruginosa
-Ceftazidime
Adds MRSA activity (the only beta-lactam with activity vs MRSA)
-Ceftarolin- only skin infections with MRSA/pseudomonas and CAP

Question 17

Unintended consequence of beta lactams

Answer 17

Skin rash including Steven’s Johnson syndrome

Question 18

Aminoglycosides

Answer 18

Acts at the ribosomal level to block protein synthesis
Renal and ototoxic with narrow therapeutic window
Renal excretion by GFR
Drug dosing guided by pharmacokinetic measurements
-Peak and trough levels guiding efficiency- have enough to work
-Limitation of toxicity- not so much as to cause end organ damage

Question 19

Quinolones

Answer 19

Cipro is not a respiratory FQ

Cipro gaining resistance for UTI! Do not use for females unless benefits > risks

Question 20

Metronidazole and tinidazole

Answer 20

Great for bacterial GI infection in combo with cipro (uncomplicated diverticulitis)
C-diff initial tx

Question 21

Linezolid (Zyvox)

Answer 21

Gram pos activity- tx for pneumonia, skin infections

Question 22

Vaccines

Answer 22

The single most effective public health measure improving health (along with hand-washing)

Question 23

Live virus attenuated vaccines

Answer 23

MMR
Yellow fever
Herpes zoster
Influenza (live cold attenuated viral strains)
Varicella