Pulmonary Mycobacterium kansasii infection in Israel, 1999-2004: Clinical features, drug susceptibility, and outcome

Background: Mycobacterium kansasii infection is one of the most common causes of nontuberculous mycobacterial lung disease in world. However, little is known about its background characteristics or drug sensitivity in nonendemic areas. Design: We assessed the clinical features, radiologic findings, and drug sensitivity associated with M kansasii infection in Israel. Methods: Patients with a culture-positive diagnosis of M kansasii infection between April 1999 and April 2004 were identified from a clinic database of tuberculosis centers. Mycobacterial cultures were performed with standard methods. Data on patient background and clinical features were collected from the medical files. Results: Mean age (± SD) of the 56 patients was 58 ± 18 years, and 64% were men; 59% had associated lung disease. Fifteen percent were receiving immunosuppressive medications. None had HIV infection. Systemic comorbid diseases were noted in 27%. The most common clinical presentations were chest pain, cough, hemoptysis, fever, and night sweats. Cavitation was noted only in 54%. Older patients had more noncavitary disease than younger patients (p = 0.01, r = 0.35). Lower-lobe predominance was very rare (4%). None of the patients presented with pleural effusion or lytnphadenopathy. Only seven patients (11%) underwent bronchoscopy for diagnosis. M kansasii isolates showed the highest sensitivity to rifampin, ethambutol, clarithromycin, and ofloxacin, and the highest resistance to ciprofloxacin and capreomycin. The mean duration of treatment was 21 ± 7.2 months. There were no disease-related deaths. Conclusions: M kansasii disease in Israel has no association with HIV, more systemic comorbid diseases and associated lung disease, and fewer cavitations. Following appropriate treatment, patients with M kansasii disease have an excellent prognosis.