Multivariate Analysis of Risk Factors for Infection Due to Penicillin-resistant and Multidrug-resistant Streptococcus Pneumoniae: a Multicenter Study

Pneumococcal disease was studied prospectively to determine the risk factors associated with resistance to penicillin and other antibiotics. One hundred twelve clinically significant pneumococcal isolates were recovered from 95 patients. Approximately one-half (49.47%) of the cases were due to penicillin-resistant strains. Multivariate analysis showed that previous use of beta-lactam antibiotics (odds ratio [OR], 2.81; 95% confidence interval [CI], 0.95-8.27), alcoholism (OR, 5.22; 95% CI, 1.43-19.01), and noninvasive disease (OR, 4.53; 95% CI, 1.54-13.34) were associated with penicillin resistance, whereas intravenous drug use (OR, 0.14; 95% CI, 0.03-0.74) was not. Statistical analyses of the variables associated with resistance to multiple antibiotics detected age of younger than 5 years (OR, 16.79; 95% CI, 1.60-176.34) or of 65 years or older (OR, 4.33; 95% CI, 1.42-13.21) and previous use of beta-lactam antibiotics by patients with noninvasive disease (OR, 7.92; 95% CI, 1.84-34.06) as parameters associated with increased risk. We conclude that multivariate analysis provides clues for empirical therapy for pneumococcal infection.