INFECTIONS CAUSED BY ERYTHROMYCIN-RESISTANT STREPTOCOCCUS-PNEUMONIAE - INCIDENCE, RISK-FACTORS, AND RESPONSE TO THERAPY IN A PROSPECTIVE-STUDY

To evaluate the incidence and the significance of resistance to erythromycin among clinical isolates of Streptococcus pneumoniae, we identified and prospectively followed all hospitalized patients in a 27-month period who had the organism isolated from any clinical sample, Patients who had an infection caused by pneumococci resistant to erythromycin (minimum inhibitory concentration, >1 mu g/mL) were compared to those with infections caused by erythromycin-susceptible organisms, The incidence of erythromycin resistance among pneumococci doubled over the study period (from 7.6% in 1988 to 15.2% in 1992). Most strains (94%) showed resistance to multiple antibiotics, including other macrolides, By multivariate analysis, an age of <5 years and nosocomial acquisition of the infection were independent risk factors for erythromycin resistance, Among patients with pneumococcal pneumonia caused by erythromycin-resistant organisms, 9 patients treated with third-generation cephalosporins were cured, while therapy with erythromycin failed for 2 of the 6 patients to whom it was administered. The rapid and significant increase of erythromycin resistance among clinical isolates of S, pneumoniae points to the need for routine surveillance of pneumococcal resistance.