Pulmonary infections by atypical mycobacteria in a rural coastal region of Karnataka, India.

The sputum specimens from 6,829 cases were obtained from patients diagnosed as "relapsed cases" of pulmonary tuberculosis and chronic non-specific respiratory diseases (CNSRD). Of these 1,191 (17.4%) were culture positive for acid fast bacilli with 292 (4.23%) human and 899 (13.7%) being atypical mycobacteria. These data imply that, if not all, most of the reported cases of relapsed pulmonary tuberculosis could be due to atypical mycobacteria in South West Coast of India and that this agent in some patients could be responsible for chronic infections of the lung as well. Practically all of these patients are from rural areas living in close contact with nature and animals. This poses the question whether atypical mycobacterial infection could be considered a zoonosis.