Pneumonia acquired in the community through drug-resistant Streptococcus pneumoniae

The aim of the study was to determine the incidence of and risk factors for drug resistance of Streptococcus pneumoniae, and its impact on the outcome among hospitalized patients of pneumococcal pneumonia acquired in the comm unity. Consecutive patients with culture-proven pneumococcal pneumonia were prospectively studied with regard to the incidence of pneumococcal drug re sistance, potential risk factors, and in-hospital outcome variables. A tota l of 101 patients were studied. Drug resistance to penicillin, cephalospori n, or a macrolide drug was found in pneumococci from 52 of the 101 (52%) pa tients; 49% of these isolates were resistant to penicillin (16% intermediat e resistance, 33% high resistance), 31% to cephalosporin (22% intermediate and 9% high resistance), and 27% to a macrolide drug. In immunocompetent pa tients, age > 65 yr was significantly associated with resistance to cephalo sporin (odds ratio [OR]: 5.0; 95% confidence interval [CI]: 1.3 to 18.8, p = 0.01), and with the presence of > 2 comorbidities with resistance to peni cillin (OR: 4.7; 95% CI: 1.2 to 19.1; p < 0.05). In immunosuppressed patien ts, bacteremia was inversely associated with resistance to penicillin and c ephalosporin (OR: 0.04; 95% CI: 0.003 to 0.45; p < 0.005; and OR: 0.46; 95% CI: 0.23 to 0.93; p < 0.05, respectively). Length of hospital stay, severi ty of pneumonia, and complications were not significantly affected by drug resistance. Mortality was 15% in patients with any drug resistance, as comp ared with 6% in those without resistance. However, any drug resistance was not significantly associated with death (relative risk [RR]: 2.5; 95% CI: 0 .7 to 8.9; p = 0.14). Moreover, attributable mortality in the presence of d iscordant antimicrobial treatment was 12%, as compared with 10% (RR: 1.2; 9 5% CI: 0.3 to 5.3; p = 0.67) in the absence of such treatment. We conclude that the incidence of drug-resistant pneumococci was high. Risk factors for drug resistance included advanced age, comorbidity, and (inversely) bacter emia. Outcome was not significantly affected by drug resistance.