OUTPATIENT USE OF ERYTHROMYCIN - LINK TO INCREASED ERYTHROMYCIN RESISTANCE IN GROUP-A STREPTOCOCCI

Resistance to erythromycin in group A streptococci has become an impor tant problem among outpatients in Finland. The prevention of such prob lems requires information about the relationship between antimicrobial consumption and antimicrobial resistance. Having found considerable v ariation among health authority areas in the proportions of group A st reptococci resistant to erythromycin, we investigated the potential im pact of local differences in the consumption of this agent on the deve lopment of resistance. In 1992, 10,162 group A streptococcal isolates (nearly 100% were from outpatients) collected from 206 health authorit y areas were tested for erythromycin resistance; 1,647 isolates (16%) were resistant, Logistic regression analysis showed that the proportio n of isolates resistant to erythromycin clearly increased with increas ing local erythromycin consumption by outpatients in 1991 (P = .006). This positive association indicates that a prudent policy for the trea tment of outpatients is essential to maintenance of the effectiveness of antimicrobial agents.