Mycobacterium kansasii: biologia patogenu oraz cechy kliniczne i epidemiologiczne zakażeń

Mycobacterium kansasii: pathogen biology and clinical and epidemiological features of infections
Z. Bakuła, A. Safianowska, M. Nowacka-Mazurek, J. Bielecki, T. Jagielski

1. Wprowadzenie. 2. Prątki niegruźlicze. 3. Charakterystyka Mycobacterium kansasii. 4. Epidemiologia. 5. Diagnostyka laboratoryjna. 6. Patogeneza i obraz kliniczny. 6.1. Interakcje patogen-gospodarz. 6.2. Źródła zakażeń. 6.3. Czynniki ryzyka. 6.4. Rozpoznanie. 6.5. Obraz kliniczny. 7. Leczenie. 8. Podsumowanie

Abstract: Nontuberculous mycobacteria (NTM) are opportunistic pathogens widely spread in the environment that may produce life-threatening infections in humans. With the increased number of patients suffering from different forms of immunosuppression, there has been a resurgence in interest in NTM and increase in the prevalence of NTM diseases. Although the incidence of Mycobacterium kansasii infections shows significant geographical variability, in most places, M. kansasii ranks first as a cause of pulmonary NTM syndromes in the HIV-negative population and second as a cause of disseminated infection in HIV-positive patients. In Poland, among cases of NTM disease, the number of which has been remarkably on the rise in recent years, those attributable to M. kansasii are in majority. Many epidemiological aspects of M. kansasii infection, concerning the pathogen’s reservoirs, contagiousness, transmission routes and distribution in different geographic regions and among different human populations, are unknown or only poorly understood. As with other NTM, M. kansasii infections are believed to be acquired from environmental exposures rather than by person-to-person transmission. Rarely M. kansasii has been isolated from soil, natural water systems or animals. Instead it has almost exclusively been recovered from municipal tap water, which is considered to be its major environmental reservoir. Culturing of M. kansasii from human tissues may not necessarily represent true infection but a non-pathogenic colonization or contamination. Thus, a reliable diagnosis of M. kansasii disease relies upon an in-depth clinical and laboratory investigation, requiring integration of symptomatological, radiological, and microbiological data. In thoracic imaging, M. kansasii infections may manifest as cavitations, opacities, small nodules and bronchiectasis, most frequently situated in the upper lobes, but lesions may also be present in other sites of the lungs. Treatment of M. kansasii infections is based on a combined and long lasting (at least 15 months) regimen consisting of ethambutol, isoniazid and rifampicin.

1. Introduction. 2. Non-tuberculous mycobacteria. 3. Characteristics of Mycobacterium kansasii. 4. Epidemiology. 5. Laboratory diagnostics. 6. Pathogenesis and clinical features. 6.1. Host-pathogen interactions. 6.2. Sources of infections. 6.4. Risk factors. 6.4. Diagnosis. 6.5. Clinical picture. 7. Treatment. 8. Summary