[Bacteriological and epidemiological observations on atypical mycobacteria isolated at the laboratory of the...

Excluding cases of clinically manifest mycobacteriosis atypical mycobacteria can be detected in the excreta of healthy subjects, of tuberculous patients, or of other patients suffering from other diseases, without any major clinical implication. In certain environment conditions however epidemiologic manifestations may be induced by these organisms, of the hospitalism type. Atypical strains of the mycobacteria isolated over a period of 10 years represent 3.17% of all isolated strains. The highest percentage according to the Runyon groups were found in the IV-th group (43%), followed by the II-nd group (with 42%), and the III-rd group (with 11%). Diffusion of mycobacteria from the II-nd and the IV-th Runyon groups has determined hospitalism phenomena that developed in two distinct epidemic outbreaks determined by different factors.