Clinical Outcome of Invasive Infections in Children Caused by Highly Penicillin-Resistant Streptococcus pneumoniae Compared with Infections Caused by Penicillin-Susceptible Strains

Background s report based on data from the Institutional Surveillance System during 1994–1998, we document the continuing emergence of drug-resistant Streptococcus pneumoniae strains at the Hospital Infantil de Mexico Federico Gómez in Mexico City. s luate the clinical course of 49 invasive pneumococcal infection outside the central nervous system (CNS) by a number of factors including the site, severity, and place where the infection was acquired, the underlying health of the patient, and the adequacy of antimicrobial therapy. s erlying illness was present in 21 of 49 (43%) patients, 37 (75%) patients had taken previous antimicrobial therapy, and 25% of the infections were nosocomially acquired. Overall, 25 of 49 (51%) of the pneumococcal strains tested were pencillin-resistant; strains with the highest resistance to penicillin were also resistant to cephalosporins. Twenty-two percent of all strains were considered to be multidrug-resistant. Eleven of 25 penicillin-resistant strains were identified as multidrug-resistant, i.e., to erythromycin, TMP/SMX, and chloramphenicol. Ten serotypes accounted for 88% of the isolates, the most frequent serotypes being 23F, 14, 19V, 6A, and 6B. The overall case-fatality rate was 37% (18 of 49), with most deaths occurring within 3–5 days after antibiotic therapy was initiated. There was no difference in the case fatality rate between children with penicillicin-nonsusceptible and penicillin-susceptible pneumococcal infections; instead; case-fatality rate correlated with severity of illness on admission and presence of underlying disease. sions terizing groups at risk for invasive pneumococcal disease could aid in the development of preventive programs and increase the benefits from wide use of future conjugated vaccines.