Read on Twitter
Case!
55 YO resp failure, persistent cough, fatigue was being worked up for ILD as an outpatient. Admitted to the hospital with abnormal Xray/CT findings. No weight loss, anorexia. H/O sandblasting for 20 years and painting septic tanks. AFB cx + in 8 d, genexpert -.
55 YO resp failure, persistent cough, fatigue was being worked up for ILD as an outpatient. Admitted to the hospital with abnormal Xray/CT findings. No weight loss, anorexia. H/O sandblasting for 20 years and painting septic tanks. AFB cx + in 8 d, genexpert -.
Tspot is positive! What is the most likely pathogen?
1/11
We are blown away at the engagement and we appreciate it. Of course, @k_vaishnani, the fastest tweeter in the world got it right. M. kansasii (Mkan) was the cause. Let's learn a little about this bug. I'm goin in...
We are blown away at the engagement and we appreciate it. Of course, @k_vaishnani, the fastest tweeter in the world got it right. M. kansasii (Mkan) was the cause. Let's learn a little about this bug. I'm goin in...
2/11
Keys in this case was a positive Tspot and the growth on AFB. Mtb complex will are slow growers usually around 4-6 weeks to grow. NTMs usually grow at 7-10 days. Attached is a classification that one of our fellows made. Its not complete but general overview.
Keys in this case was a positive Tspot and the growth on AFB. Mtb complex will are slow growers usually around 4-6 weeks to grow. NTMs usually grow at 7-10 days. Attached is a classification that one of our fellows made. Its not complete but general overview.
3/11
Our patient's cultures were like so, one image was stolen from the internets, note the beaded appearance on biopsy:
Our patient's cultures were like so, one image was stolen from the internets, note the beaded appearance on biopsy:
4/11
Runyon classification:
1 Photocromogens (yellow w light) Mkan, Marinum. Szulgai is a photchromogen low temp
2 Scotochromogens (always yellow) Gordonae, scrofulaceum
3 Nonchromogens (no pigment) MAC/MAI, Ulcerans, Chimera
4 Rapid growers (5d) Fortuitum, Abscessus, Chelonae
Runyon classification:
1 Photocromogens (yellow w light) Mkan, Marinum. Szulgai is a photchromogen low temp
2 Scotochromogens (always yellow) Gordonae, scrofulaceum
3 Nonchromogens (no pigment) MAC/MAI, Ulcerans, Chimera
4 Rapid growers (5d) Fortuitum, Abscessus, Chelonae
5/11
IGRAs (Tspot and Quantiferon) both test for reaction to antigens ESAT6 and CFP10 but Quant checks simultaneously and Tspot individually. Our fellow has adapted this sweet chart to show you possibility of other Mycobacterium with positive IGRA:
IGRAs (Tspot and Quantiferon) both test for reaction to antigens ESAT6 and CFP10 but Quant checks simultaneously and Tspot individually. Our fellow has adapted this sweet chart to show you possibility of other Mycobacterium with positive IGRA:
6/11
-Back to Mkan. Mimic of Mtb causing upper lobe pneumonia.
-Associated with Silicosis (for our patient), middle aged men, COPD
-Tap water is its home
-HIV, 2nd most common NTM infection
-Long term steroid use
-Can mimic sportrichoid pattern on skin
Mandell to the rescue:
-Back to Mkan. Mimic of Mtb causing upper lobe pneumonia.
-Associated with Silicosis (for our patient), middle aged men, COPD
-Tap water is its home
-HIV, 2nd most common NTM infection
-Long term steroid use
-Can mimic sportrichoid pattern on skin
Mandell to the rescue:
7/11
Thought to be associated with hairy cell leukemia but other observational studies have shown it is associated with other neoplasms and immunosuppressive processes:
Thought to be associated with hairy cell leukemia but other observational studies have shown it is associated with other neoplasms and immunosuppressive processes:
8/11
American Thoracic Society has a diagnostic criteria for NTM lung disease:
American Thoracic Society has a diagnostic criteria for NTM lung disease:
9/11
- Treatment varies by country, see image.
- The goal is negative sputum at 12mo however negative at 4 mo predicts <1% treatment failure, 4-6 mo predicts about 10% failure and if fails at 12 mo, consider surgery
-Another PZA resistant bug, INH MIC50 is high, not used in UK
- Treatment varies by country, see image.
- The goal is negative sputum at 12mo however negative at 4 mo predicts <1% treatment failure, 4-6 mo predicts about 10% failure and if fails at 12 mo, consider surgery
-Another PZA resistant bug, INH MIC50 is high, not used in UK
11/11
Our patient is still being treated and tolerating treatment well. Fingers crossed.
Our patient is still being treated and tolerating treatment well. Fingers crossed.
11/11
Bibliography:
-Mandell et al Principles and Practice of Infectious Diseases
-DeStefano et al. Frontiers in Microbiology Vol 9 (September 24, 2018).
-Han et al Journal of Korean Medical Science 25, no. 2 (February 2010): 304–8.
Credit @MBrigmon
Bibliography:
-Mandell et al Principles and Practice of Infectious Diseases
-DeStefano et al. Frontiers in Microbiology Vol 9 (September 24, 2018).
-Han et al Journal of Korean Medical Science 25, no. 2 (February 2010): 304–8.
Credit @MBrigmon
