Pulmonary Mycobacterium kansasii Infection in Israel, 1999-2004: Conclusion
The present report supports M kansasii susceptibility to clarithromycin and ofloxacin.2′ Ofloxacin was also superior to ciprofloxacin (Table 2). We believed that some isolates are susceptible to slightly higher ciprofloxacin concentrations; therefore, when clinically indicated, ciprofloxacin should be used regardless of the in vitro susceptibility results. M kansasii infection affects middle-aged men more than women. The most common associated lung disease in the present series was COPD, although approximately 40% of the patients had no recognized immune defect. This has been reported in other studies as well. The chest radiograph findings in M kansasii infection are very similar to pulmonary tuberculosis, including cavitary infiltrates with an upper-lobe predilection (82% vs 4% for the lower lobe in the present study). However, noncavitary lung disease has also been recognized as part of the spectrum of M kansasii mfection.> Our study showed that cavitary disease occurred only in 54%. Like in the report of Evans et al, none of our patients had pleural effusion or lymphadenopathy. Lower rate of cough, cavitation, and upper-lobe predominance on chest radiograph were noted in patients receiving immunosuppressive medications in our study compared to the same patients in other studies. However, the number of patients with recognized immune defect in our series was low (n = 8, 14%).
There were some differences in the clinical manifestation of M kansasii infection between our study population and that described by Evans et al (Table 1). We found fewer patients with weight loss and more patients with fever and night sweats. These differences may have been due to the short interval from symptom onset to diagnosis, so that most of our patients presented with symptoms of acute infection.
According to the ATS guidelines, the current duration for treatment of pulmonary disease caused by M kansasii is 18 months with an least 12 months of negative sputum culture results. The mean duration of positive culture results in our patients was long (8.9 to 10.3 months), and therefore the total duration of the treatment was longer (21 ± 7.2 months). The presence of more systemic comorbid diseases and associated lung disease could attribute to that. Following appropriate treatment, however, patients with M kansasii disease have an excellent prognosis. http://mycanadianfamilypharmacy.net/
Our study has several limitations. The first is the retrospective design with the use of medical records for data collection. The second is the absence of molecular characterization of the isolates. Every genotype described so far has a different clinical significance. However, pilot tests of 20 of the M kansasii isolates in our series yielded M kansasii type I in 18 isolates and type II in 2 isolates, a relative incidence consistent with other published re-ports. Third, we did not examine the drug susceptibility of the fluoroquinolones such as levofloxa-cin, gatifloxacin, and moxifloxacin.
In summary, M kansasii infections in Israel affect mainly middle-aged men without a recognized immune defect. The infection appears to be associated with a higher rate of COPD and a higher rate of fever and night sweats at presentation, and less weight loss than in other series, and with less cavitation on chest radiograph. It is also apparently not associated with HIV. Pleural effusion and lymph-adenopathy are very uncommon. Clarithromycin and ofloxacin seem to be as effective for treatment as ethambutol.