Non-Tuberculous Mycobacterial Diseases

Question 1

Approximately what percentage of Mycobacterial diseases are caused by non-tuberculous bacteria?

Answer 1

10%

Question 2

What are two unique characteristics of non-tuberculous bacteria?

Answer 2

Not communicable from person to person
Often resistant to standard TB drugs

Question 3

What is the most common non-tuberculous mycobacteria?

Answer 3

Mycobacterium Avium Complex

Question 4

What two systems does Mycobacterium Avium Complex infect?

Answer 4

Lungs
Lymph

Question 5

What two systems are most commonly affected by non-tuberculous mycobacteria?

Answer 5

Lungs (77%)
Skin and Soft Tissue (12%)

Question 6

Non-tuberculous mycobacteria infections of the Skin and Soft Tissue commonly appear where?

Answer 6

Extremities
- community outbreaks from tattoo parlors

Question 7

Disseminated infection of MAC is most commonly seen in patients with what?

Answer 7

Late Stages of HIV
- CD4 less than 50/mcL

Question 8

How do you treat a disseminated infection of MAC?

Answer 8

Clarithromycin or Azithromycin + ethambutol
- may also add Rifabutin

Question 9

What are the two major phenotypes of MAC Lung Disease?

Answer 9

Nodular + Brochiectatic (NB)
Fibrocavitary (FC)

Question 10

Nodular + Brochiectatic is typically found in what types of patients?

Answer 10

Post-menopausal White Women who don’t Smoke

Question 11

What is Nodular + Brochiectatic MAC commonly known as?

Answer 11

Lady Windermere Syndrome

Question 12

What is the clinical course of Nodular + Brochiectatic MAC?

Answer 12

Prolonged Cough
Fatigue
Weight Loss
- 50% won’t Progress
- 33% may spontaneously convert to negative

Question 13

What might you find on a CT of a patient with Nodular Brochiectatic MAC?

Answer 13

Bronchiectasis with Nodules
“Tree-in-Bud Appearance

Question 14

Where is Nodular + Brochiectatic MAC usually found inside the lungs?

Answer 14

Right Middle Lobe

Question 15

What type of patients develop Fibrocavitary MAC?

Answer 15

50+ year old male with an underlying chronic lung condition

Question 16

What is the clinical course of Fibrocavitary MAC?

Answer 16

Progressive
Systemic Symptoms
Worse Outcome and Prognosis than NB type

Question 17

Where is Fibrocavitary MAC usually found inside the lungs?

Answer 17

Upper Lobe

Question 18

Over half of the patients who meet the diagnostic criteria for MAC Lung Disease progress within 3 - 5 years, which means you as a provider should do what?

Answer 18

Start treatment
- don’t wait you fool

Question 19

What type of susceptibility testing should be performed when beginning to treat MAC?

Answer 19

Macrolide-Resistance

Question 20

How long should MAC be treated for

Answer 20

12 months

Question 21

What three medications are used to treat MAC?

Answer 21

Clarithromycin or Azithromycin
Rifampin or Rifabutin
Ethambutol

Question 22

What other Non-tuberculous Mycobacteria can infect the lungs?

Answer 22

M. kansasii

Question 23

How long is pulmonary M. kansasii treated for?

Answer 23

18 months

Question 24

What three drugs are used to treat pulmonary M. kansasii?

Answer 24

Isoniazid
Rifampin
Ethambutol

Question 25

How should skin and soft tissue infections caused by M. kansasii should be treated?

Answer 25

Surgical Debridement
Two ABX (3 months)

Question 26

What can arise if only Macrolide monotherapy is given?

Answer 26

Macrolide Resistance

Question 27

A 2014 study found that only what percentage of patients with MAC were being treated correctly?

Answer 27

13%