ID Exam 2 Pneumonia and opportunistic infections

Question 1

Predisposing factors to opportunistic infections and bugs

Answer 1

Granulocytopenia (chemo/radiation): G- and staph
Cellular immune dysfxn (T-cell): intracellular
Humoral dysfxn (B-cell): encapsulated
Foreign body (cath, implant): G- and staph
Surgery: staph, e-coli, pseudo

Question 2

Iron states and relation to infection

Answer 2

High iron states promote infection
Host response is to down regulate iron absorption during infection (fever)
Hemochromatosis can predispose to infection

Question 3

Acinetobacter baumanni

Answer 3

Common is desert soil
Infected wounds of soliders in Iraq
Acts pseudo like

Question 4

Pseudo aeruginosa: characteristics

Answer 4

G- rod, oxidase +, catalase + (CGD assoc), obligate aero
Thrives in aquatic environments
Encapsulated

Question 5

Pseudo aeruginosa and CF infections

Answer 5

Higher calcium secretion (as chloride is sequestered)
Calcium creates cross-linking of alginate
Can’t cough up pseudo

Question 6

Pseudo virulence

Answer 6

High resistance mechs (efflux pumps)
Biofilm forming
Exotoxin A: similar to diptheria, ribosylation of EF2

Question 7

Pseudo associations

Answer 7

Burn patients
Nosocomial pneumonia and UTI's
Respiratory failure in CF
Osteomyelitis (IV drug users, diabetics)
Hot tub folliculitis
Otitis externa
Systemic infection: ecthyma gangrenosum

Question 8

Treatment of pseudomonas

Answer 8

Piperacillin

Also AG’s and FQ’s

Question 9

1st cause of death from infection

Answer 9

The PNEUMONIA

Question 10

PNA most likely bugs:
Acute presentation, 19 years old
Acute presentation, 65 years old
Subacute, Asian immigrant
Subacute, HIV

Answer 10

Mycoplasma
Strep. pneumo
TB
PCP

Question 11

Mycoplasma pneumo

Answer 11

No cell wall, don’t gram stain
Lots of cholesterol in membrane
Atypical, walking pneumo (CXR looks worse than clinical)
Young adults, close contact (esp. military recruits)
Cold agglutination of RBC’s by IgM (dx test)
Culture: Eaton’s agar
Tx: macs (no cell wall)

Question 12

Atypical PNA bugs

Answer 12

Myco. pneumo
Chlam. pneumo
Legion. pneumo
Influenza, RSV, adenovirus

Atypical spelling of MILC

Question 13

Typical PNA bugs

Answer 13

Strep pneumo
H. Flu
M. catarrhalis
S. aureus

Steamboat Springs Has Moose? (so Typical)

Question 14

Complications of CAP

Answer 14

Effusion
Respiratory failure
Cavitation
Pneumothorax
PE
CVD: CHF/MI/CVA/Afib

Question 15

Strep pneumo diseases

Answer 15

Meningitis
Otitis media
Pneumonia
Sinusitis/bronchitis

Question 16

Strep pneumo pathogenesis

Answer 16

Aspiration into lungs
Adhere to epithelium (Cho-P on bug with platelet activating factor on epi)
Epi injury (H2O2 and pneumolysin [similar to streptolysin])

Question 17

Host defense agains strep pneumo

Answer 17

Bind IgA antibody and don’t bind epi
Bind Fc region with macrophage on other end
Bind epi and activate PMN’s via cytokines

Question 18

How sick is a PNA patient?

Answer 18

C - confusion
U - uremia
R - respiratory rate >30
B - BP < 90/60
65 >65 y/o

> /=3 -> ICU
2 = ward
=1 -> outpatient

Question 19

CAP treatment: 4 groups

Answer 19

Previously healthy outpatient: mac; doxy
Outpatient w/ comorbid: FQ; mac + augmentin
Inpatient not ICU: FQ; mac + ßlactam/3rd cef
Inpatient ICU: 3rd cef + FQ/mac (anti-pseudo ßlactam)

Question 20

Encapsulated disease

Answer 20

Meningitis: Strep pneumo>N. men>H. flu
PNA: Strep pneumo>H. flu
Otitis media: Strep pneumo, Moraxella sp, H. flu

Question 21

H. flu: characteristics

Answer 21

Gram- coccobaccilus
Chocolate agar (Factor V and Factor X)
V= nicotinamid (NAD), X= hematin
Blood agar: grows close to s. aureus
Aersol transmission

Question 22

H. flu: disease

Answer 22

Epiglottitis
Otitis media
Meningitis (capsular form, type B)
Splenectomy: aseptic arthritis

Phylis’ shop is next to MOES bagels

Question 23

H. flu: vaccine and treatment

Answer 23

Vaccine against type B capsule
Polysacchride of H. flu conjugated to diptheria toxoid
Give at 2-18 months
Treatment: ceftriaxone, rifampin for close contacts in meningitis

Question 24

N. men: characteristics and pathogenesis

Answer 24

Respiratory spread/nasopharynx colonization
Ferments maltose
Encapsulated
LOS (version of LPS) causing SIRS, DIC (petchial rash)
Waterhouse Friderichsen syndrome (adrenals)

Question 25

Strep pneumo

Answer 25

sketchy

Question 26

Strep pneumo vaccine

Answer 26

Pneumovax (PPSV23): Not useful in children, given to older adults/elderly as re-vaccine
Prevnar (PCV13): Conjugated, given in children

Question 27

N. men: vaccine and treatment

Answer 27

Tx: ceftriaxone, rifampin for close contact prophylaxis

Vaccine to A, C, and D (not B, opposite of H. flu)