Tuberculosis and Non-mycobacterial Lung Infections Flashcards
Imaging findings in NTM infections
CXR with nodules/cavities OR
HRCT with multifocal bronchiectasis and multiple small nodules
Micro requirements for NTM infection
Positive sputum cultures (not smear) x 2
or
Positive bronchail was culture
or
Histopath +/- “expert consultation”
3 situations where routine susceptibility testing for NTM is recommended
- MAC isolates - clarithromycin only
- M. kansasii - rifampin only
- Rapid growing mycobacterium
Rapid growing mycobacterium
M. fortuitum
M. abscessus
M. chelonae
How to prevent health care related NTM infections
NO wound, injection site, or IV catheter be exposed to tap water or tap water derived fluids
NTM pathogens considered contaminants
M. Gordonae
M. terrae complex
M. mucogenicum
5 NTM species known to be present in tap water
M. abscessus
M. kansasii
M. lentiflavum
M. simiae
M. xenopi
Gene responsible for macrolide resistance in NTM infections
erythromycin methylase (ERM)
Who gets prophylaxis agains disseminated MAC and what regimen
AIDS patients with CD4 count < 50
Azithromycin 1,200 mg/week
or
Clarithromycin 1,000 mg/day
or
Rifabutin 300 mg/day
Treatment regimen for pulmonary limited MAC
- 3 times per week dosing with
- Clarithromycin 1,000 mg or Azithromycin 500 mg
- Ethambutol 25 mg/kg
- Rifampin 600 mg
- DAILY dosing if
- Severe disease
- Cavitary lesions
- Previously treated disease
- DURATION = culture negative x 1 year
Treatment for disseminated MAC
- Daily treatment with
- Clarithromycin 1,000 mg or Azithromycin 250 mg
- Ethambutol 15 mg/kg
- Rifabutin 150 - 350 mg
- DURATION
- symptoms resolve AND cell mediated immune function returns
Treatment of pulmonary limited M. Kansasii
Daily treatment with
- Isoniazid 300 mg
- Rifampin 600 mg
- Ethambutol 15 mg/kg
DURATION = culture negative x 1 year
Treatment of pulmonary limited M. abscessus
No clinically reliable treatment, perhaps surgery
Macrolide may or may not work depending on ERM gene
- Amikacin 10-15 mg/kg 3-5x/week OR
- Tigecycline 25-50 mg/day OR
- Zyvox 300 - 600 mg/day
Should household contacts of patients with confirmed pulmonary TB be tested and treated for latent TB
Yes
Populations without HIV who should be tested for latent TB
Dialysis patients
Patients about to receive transplant
Patients with silicosis
Populations who should not be screened for latent TB
Diabetics
ETOH abuse
Smokers
Underweight individuals
People who may be considered for screening for latent TB but not mandated
Prisoners
Health care workers
Immigrants from countries with high TB burden
Homeless
Drug users
People whom 5 mm is cut off for positive PPD
HIV patients
Recent TB contacts
Prior hx of TB
Organ transplant recipients
Immunosuppressed
People for whom 10 mm is the cut off for positive PPD
Recent immigrants
IV drug users
High risk employees/residents
Silicosis
ESRD
DM
Heme malignancies
Gastrectomy or ileal bypass
Kids < 5 years old
Will quantiferon or TSPOT tests show false positive with BCG vaccine history
No, but a simple PPD will
Treatment regimens for TB in low incidence countries
- INH x 6 months
- Rifapentine + INH weekly for 3 months if HIV +
- Rifampicin + INH for 3-4 months
- Rifampicine alone for 3-4 months
TB treatment options if from high incidence country
- INH monotherapy for 6 months
- Rifapentine + INH weeks for 3 months
- Rifampicin + INH for 3 months if < 15 years of age
- INH for 36+ months if HIV+
Side effects from INH
LIver disease, CNS symtpoms, and peripheral neuropathy if B6 deficient
Side effects from rifamycins
Turns body fluids orange, liver toxicity
