[Study on drug resistance of Mycobacterium tuberculosis in different age group].
OBJECTIVE
To investigate drug resistance of Mycobacterium tuberculosis in different age group in recent five years, and to analyze the trends of drug resistance at present.


METHODS
1 948 cases of pulmonary tuberculosis with culture-positive were divided into youth group (18 approximately 39 years), middle age group (40 approximately 59 years) and old age group (>/=60 years). All of the strains of Mycobacterium tuberculosis were tested for resistance to INH, RFP, SM and EMB by the absolute concentration method.


RESULTS
The rate of primary drug resistance in youth group was 36.1%, in middle age group 46.8%, in old age group 40.2%, there were no significant differences among them (P > 0.05). The rate of acquired drug resistance was higher in youth group than that in old age group (P = 0.019 6). The primary resistance rate to RFP in middle age group was 10.6%, much higher than that in youth group and in old age group. The acquired resistance rate to RFP in youth group was 63.6%, higher than that in middle age group and in old age group. The rate of primary multi-drug resistance in middle age group was 5.3%, higher than that in youth group (P = 0.011 2) and in old age group (P = 0.008 5). The rate of acquired multi-drug resistance in youth group was 55.2%, higher than that in middle age group (P = 0.031 9) and in old age group (P < 0.001). The drug resistance rate in using drugs 1 approximately 3 months group was 58.7%, higher than that in never using drug group (P < 0.001) and in using drugs < 1 month group (P = 0.047 2). The drug resistance rate had no significant difference between never using drug group and using drugs < 1 month group. The emergency of drug resistance in youth group was fastest in all age groups.


CONCLUSIONS
Primary drug resistance or acquired drug resistance varies in different age group. It is suggested that the surveillance of drug resistance in different age group should be taken seriously, so as to provide an important basis for revising National Tuberculosis Programme (NTP).
Tang
S
S
Shanghai Pneumology Hospital, Shanghai 200433, China.
Xiao
H
H
Xia
X
X
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D006801:Humans; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000302:isolation & purification; D014397:Tuberculosis, Pulmonary / Q000382:microbiology*
D000900:Anti-Bacterial Agents