OBJECTIVETo analyze the current situation and trend of Mycobacteria other than tuberculosis (MOTT) in the old city area of Guangzhou and to provide information for diagnosis, treatment and policy on tuberculosis (TB) control in the city.

METHODSRelevant data regarding Mycobacteria culture, species identification and drug-resistance from out-patients under suspicion of having pulmonary tuberculosis seen at our TB and Pulmonary Tumor Control Institute, was analyzed retrospectively during 1994-2003.

RESULTSA total number of 12,634 strains of Mycobacteria were isolated and 794 strains were identified as MOTT which accounted for 6.28% of the isolated strains during the ten years. The annual isolation rates of MOTT were between 3.51% and 10.06%. When compared with 1994, the rates of isolation on MOTT had increased 73.15% in 2003, i.e. from 5.81% in 1994 to 10.06% in 2003. 512 strains were not susceptible at least to rifampin and isoniazid out of 613 MOTT strains tested for drug susceptibility to isoniazid, rifampin, streptomycin sulfate and ethambutol. The average rate of multi-drugs resistance of these strains was 83.5%, and the annual rates were between 71.4% and 93.9%. Based on the results of species identification on 136 strains of MOTT in 2003, most of them belonged to pathogenic/opportunistic species of Mycobacteria. All together, 30 strains of M. abscessus, 26 of M. intracellulare, 17 of M. smegmatis, 14 of M. scrofulaceum, 11 of M. avium, 5 of M. kansasii and M. chelonae and M. fortuitum respectively, 4 of M. nonchromogenicum, 2 of M. triviale and 1 of M. aurum were identified. People at 45 years of age or older, with 55-65 the most, were more susceptible to MOTT than other age groups. Sex ratio was 3.36 to 1.

CONCLUSIONBased on information from the Third National Tuberculosis Epidemiology Survey in 1990 and the Fourth one in 2000, the current situation and trend of MOTT were nearly the same in the old city area of Guangzhou during 1994-2003. However, the rising tendency of rate of isolation, mainly consisted of opportunistic pathogens and the surprisingly high rate of multi-drugs resistance to MOTT all call for special attention. Studies regarding the epidemiology of MOTT should be posed and implemented in the National TB Control Program.