51 terms

Non-TB Mycobacteria

Are non-TB mycobacteria transmitted human-to-human?
Is there any need for infection control precautions?
Where can you find non-TB mycobacteria?
What organisms are the Rapid Growers and how long does it take for them to grow?
-M. Fortuitum, Chelonae, Abscessus

days in broth
<1 weeks on solid media
How long does it take slow growers to grow?
1-2 weeks in broth
2-4 weeks on solid
What organisms have special diagnostic problems?
M. leprae--can't be cultured
M. marinum--lower temperature required
What 3 criteria are necessary in order to make a diagnosis of NTM?
1. Compatible clinical syndrome
2. Abnormal CXR or HRCT
3. Bacteriologic criteria (2 positive sputum cultures; positive culture from BAL; positive granuloma or AFB on biopsy WITH NTM on sputum)
What NTM mimics tuberculosis in that it is a fibrocavitary disease and shows systemic symptoms?
MAC in Association with COPD
What NTM is associated with weight loss?
MAC Pulmonary Disease in Non-Smoking Female Patients
What NTM may need an HRCT scan to diagnose?
MAC Pulmonary Disease in Non-Smoking Female Patients
What NTM shows diffuse infiltrates and nodularity on CXR/CT?
Hypersensitivity Pneumonitis "Hot Tub Lung"
What NTM shows nodular bronchiectasis/interstitial disease?
MAC Pulmonary Disease in Non-Smoking Female Patients
How long is treatment for NTM?
1-2 years
Is empiric therapy indicated for NTM?
What is the treatment for Pulmonary MAC?
Treat with 3 or more active drugs, usually for 18-24 months.
Obtain a monthly sputum culture and continue treatment until culture-negative for 12 months.
What CD4 cell count is Disseminated MAC in Patients with AIDS found commonly in?
<50 CD4 T cells
Where can Disseminated MAC be found in the US?
Geographically widespread
How is Disseminated MAC acquired?
Could be GI, could be Respiratory
How do you diagnose someone with Disseminated MAC?
Blood cultures usually positive but bone marrow, liver or lymph node biopsy would be reasonable if blood cultures repeatedly negative
What happens to patients who undergo HAART?
Local MAC symptoms may worsen
What happens to the worsening patients undergoing HAART?
They will improve over a few weeks with no change in treatment
What do you treat the symptoms of IRIS patients with?
NSAIDS, or in extreme cases, steroids
What should HIV patients with CD4 cells of <50 do to avoid acquiring MAC?
Prophylactic Azithromycin or Clarithromycin

or Rifabutin

May discontinue when CD4 >100
What is the most treatable NTM?
M. kansasii
What is the treatment for M. kansasii?
INH + ethambutol + rifampin for 12 months
What NTM usually affects kids 1-5 and RARELY in adults?
NTM Lymphadenitis
What are the most common areas affected by NTM Lymphadenitis?
Bilateral or Unilateral?
Head and Neck
How do you diagnose NTM Lymphadenitis?
Fine needle aspiration or Excisional biopsy
What is the treatment for NTM Lymphadenitis?
Surgical removal of involved nodes
Is relapse common in NTM Lymphadenitis?

If relapse: repeat surgery or start chemo
What is the course of M. marinum?
1 to 2 months of incubation, followed by granulomatous nodular-ulcerative lesions
Where are lesions common with M. marinum?
What to think of when you hear M. marinum
What is the treatment for M. marinum? What is unique to this treatment?
Clarithromycin + ethambutol

Should continue treatment 1-2 months after symptoms resolve
What are the 2 problems that Rapid Growers cause?
1. Skin problems
2. Lung problems
Which Rapid Growers are involved in skin/soft tissue infections?
All 3
Which Rapid Growers are involved in Pulmonary infections?
M. fortuitum, M. abscessus
Which Rpiad growers are most responsible for Health-care Associated Mycobacterial Outbreaks?
M. fortuitum and M. abscessus
What kind of Health-care things are Mycobacteria associated with?
Surgical wounds, prosthetics, implants, LASIK, catheters
Related to WATER contamination
What is the treatment regimen for M. fortuitum?
2-3 drugs for 4-12 months

Shorter for Skin--Longer for Lung
What is the most difficult Rapid Grower to treat?
M. abscessus
What is the treatment for M. chelonae?
2 drugs for 4 to 6 months

Where is leprosy common?
Tropical countries
What is the route of transmission of leprosy?
Can M. leprae be cultured?
Is M. leprae contagious?
What are the different types of Leprosy syndromes?
What is Lepromatous Leprosy like?
High bacillary load
Deformity of face
What is Tuberculoid Leprosy like?
FEW bacilli
<5 skin lesions
Anesthesia present
React to M. Leprae skin tests
NERVE involvement
How do you treat Lepromatous Leprosy?
2 years of :
Dapsone + rifampin + clofazimine
How do you treat Tuberculoid Leprosy?
6 months of
Dapsone + Rifampin