Authors' reply

Initially, on behalf of our team, I would like to thank the authors for their correspondence, aimed at the exchange of ideas about a complex clinical condition. The challenge of treating respiratory infection with mycobacteria of the Mycobacterium abscessus complex is established from the outset, either by the difficulty of isolating and identifying the bacteria, or by the fact that the patients are critically ill, typically developing structural lung changes prior to becoming ill.(1)

Respiratory infections caused by nontuberculous mycobacteria (NTM) represent an emerging public health problem. In a survey conducted in Germany in 2017 and involving patients with health insurance, the rate of hospitalization was three times higher among those infected with NTM than among controls matched for age, gender, and the Charlson comorbidity index, such hospitalizations accounting for 63% of total costs.(2)

In Brazil, access to centers that perform genotype identification remains limited, as does access to sensitivity testing, constituting an impasse in the clinical approach to patients with respiratory infection caused by NTM. According to the 2017 guidelines of the British Thoracic Society, when M. abscessus is isolated, sensitivity tests should be performed, those tests including at least three antibiotics (clarithromycin, cefoxitin, and amikacin), as well as (ideally) tigecycline, imipenem, minocycline, doxycycline, moxifloxacin, linezolid, cotrimoxazole, and clofazimine.(3)

The abovementioned wide variety of drugs compose the therapeutic arsenal available for use, which is nevertheless of limited efficacy because of the bacterial resistance of the M. abscessus complex, mainly to macrolides and aminoglycosides. This excessive number of drugs creates barriers to a satisfactory clinical outcome,(1) the main barriers being the prolonged duration of treatment, which makes adherence difficult; the high incidence of adverse effects; the long hospital stay (due to parenteral administration of drugs); and the high economic cost.

Considering that respiratory infections caused by the M. abscessus complex are far from being under control in many countries, the exchange of information is always of great value, increasing knowledge and building a body of scientific evidence regarding such infections.

REFERENCES

1. Monteiro JTC, Lima KVB, Barretto AR, Furlaneto IP, Gonçalves GM, Costa ARFD, et al. Clinical aspects in patients with pulmonary infection caused by mycobacteria of the Mycobacterium abscessus complex, in the Brazilian Amazon. J Bras Pneumol. 2018;44(2):93-98. https://doi.org/10.1590/s1806-37562016000000378
2. Diel R, Jacob J, Lampenius N, Loebinger M, Nienhaus A, Rabe KF, et al. Burden of non-tuberculous mycobacterial pulmonary disease in Germany. Eur Respir J. 2017 Apr 26;49(4). pii: 1602109. https://doi.org/10.1183/13993003.02109-2016
3. Haworth CS, Banks J, Capstick T, Fisher AJ, Gorsuch T, Laurenson IF, et al. British Tho-racic Society guidelines for the management of non-tuberculous mycobacterial pul-monary disease (NTM-PD). Thorax. 2017;72(Suppl 2):ii1-ii64. https://doi.org/10.1136/thoraxjnl-2017-210927