TB, C Diff, IRIS

Question 1

TB

• natural course
• microorganism

Answer 1

mycobacterium TB

exposure/infection –>10% active, 90% latent
10% of latent will develop active TB, highest in the first 2 years

Question 2

TB presentation

Answer 2

SOB, fever, night sweats, haemoptysis, pleuritic chest pain

CXR - hilar lymphadenopathy, UL lesions, cavitating

Question 3

TB Ix - Screening

Answer 3

1. Quantiferon Gold
   - tests for interferon gamma
   - +ve within 4-6 weeks of exposure
2. Mantoux skin test
   - induration on skin tested
   - can be positive with previous BCG
   - can cause anaphylaxis

both don’t have excellent sensitivity - can’t use for symptomatic patients

Question 4

TB Ix - Symptomatic

Answer 4

CXR
Sputum AFB (morning) x3
Culture (most sensitive but takes a while) - sensitivity will help with abx regime

Question 5

TB Rx Active

Answer 5

Check visual acuity, eGFR, HIV, Hep serology and bloods prior

RIPE x2/52 then RI for 4/52
Rifampicin, Isonaizid, Ethambutol, Pyrazinamide

Can stop ethambutol once sensitive to Rifampicin and Isonaizid confirmed
Stop Pyrazinamide after 2m if sensitivities confirmed

Question 6

Latent TB - rx

Answer 6

Isoniazid x9/12

or Rifampicin x4/12 or both for 3/12

Question 7

AE Ethambutol

Answer 7

optic neuritis

Question 8

AE Rifampicin

Answer 8

orange reg bodily fluids

hepatic toxicity

Question 9

Isoniazid

Answer 9

peripheral neuritis, hepatic and renal toxicity

Question 10

TB MDR - definition and RF

Answer 10

no response to treatment in 3/12

RF - place of birth, exposure to people with MRD or have previously been treated for TB

Question 11

C diff testing

Answer 11

C diff toxin PCR

will be negative for weeks post, don’t retest

Question 12

C diff severe - definitions

Answer 12

fever >38.5 or rigours
haemodynamic instability
peritonitis or bowel perf
ileus or toxic megacolon
elevated WCC
Elevated lactate
Cr >50% rise from baseline
**Pseudomembranous colitis on colonoscopy

Question 13

C diff Rx

Answer 13

First episode - PO metro or PO vans
Second episode -PO vanc or Fidoxomicin
Severe - Vanc PO +/- Metro

Recurrent or refractory disease (>3)- feral microbiota tx

Question 14

IRIS - definition

Answer 14

“Immune reconstitution inflammatory syndrome” (IRIS) describes a collection of inflammatory disorders associated with paradoxical worsening of preexisting infectious processes following the initiation of (ART) in HIV-infected individuals

Question 15

IRIS - disease associated

Answer 15

TB
HIV
Steroid withdrawal
discontinuation of anti TNF alpha