Nationwide survey of drug resistance of S. pneumoniae in the pediatric field in Japan

BackgroundStreptococcus pneumoniae is a major causative pathogen of pneumonia in children. The Drug-Resistant Pathogen Surveillance Group in Pediatric Infectious Disease conducted a nationwide surveillance of S. pneumoniae in 2000-2001, 2004, 2007, 2010 and 2012, and investigated changes in drug resistance of S. pneumoniae. MethodsAll strains of S. pneumoniae were isolated from clinical specimens collected from pediatric patients. The minimun inhibitory concentration was measured and the strains were classified according to the Clinical Laboratory Standards Institute criteria. The isolation rates of penicillin-intermediate resistant S. pneumoniae (PISP) and penicillin-resistant S. pneumoniae (PRSP) were compared based on seven patient factors. Logistic regression analysis was also performed. ResultsThe sum of the isolation rates for PISP and PRSP for each period was 64.6%, 67.0%, 56.2%, 76.9% and 49.5%, respectively. Among the patient factors, age category 1 (<3 years, 3 years), age category 2 (infant, toddler and preschooler, schoolchild), siblings (absence, presence), and pre-treatment with antimicrobial agents (absence, presence) were associated with significant differences in the isolation rate of PISP + PRSP. An interaction was observed between pre-treatment with antimicrobial agents and schoolchild, and the isolation rate of PISP + PRSP was higher in patients with both pre-treatment with antimicrobial agents and schoolchild. ConclusionAlthough some changes were observed in the rate of resistance of S. pneumoniae, an increasing trend was not observed. Both pre-treatment with antimicrobial agents and age were associated with resistance, and an interaction was observed between pre-treatment with antimicrobial agents and schoolchild.