Clinical outcome of invasive infections in children caused by highly penicillin-resistant Streptococcus pneumoniae compared with infections caused bypenicillin-susceptible strains

ing 1994-1998, we document the continuing emergence of drug-resistant Strep tococcus pneumoniae strains at the Hospital Infantil de Mexico Federico Gom ez in Mexico City. Methods. We evaluate the clinical course of 49 invasive pneumococcal infect ion outside the central nervous system (CNS) by a number of factors includi ng the site, severity, and place where the infection was acquired, the unde rlying health of die patient, and the adequacy of antimicrobial therapy. Results. An underlying illness was present in 21 of 49 (43%) patients, 37 ( 75%) patients had taken previous antimicrobial therapy, and 25% of the infe ctions were nosocomially acquired. Overall, 25 of 49 (51%) of the pneumococ cal strains tested were pencillin-resistant; strains with the highest resis tance to penicillin were also resistant to cephalosporins. Twenty-two perce nt of all strains were considered to be multidrug-resistant. Eleven of 25 p enicillin-resistant strains were identified as multidrug-resistant, i.e., t o erythromycin, TMP/SMX, and choramphenicol. 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 occ urring within 3-5 days after antibiotic therapy was initiated. There was no difference in the case fatality rate between children with penicillicin-no nsusceptible and penicillin-susceptible pneumococcal infections; instead; c ase-fatality rate correlated with severity of illness on admission and pres ence of underlying disease. Conclusions. Characterizing groups at risk for invasive pneumococcal diseas e could aid in the development of preventive programs and increase the bene fits from wide use of future conjugated vaccines. (C) 2001 IMSS. Published by Elsevier Science Inc.