P0548 BACILLARY DYSENTERY IN CHILDREN- A LINGERING PUBLIC HEALTH PROBLEM IN TAIWAN

Abstract

Introduction: Shigellosis is primarily a disease of poor, crowded communities that do not have adequate sanitation or tap water. Occasional outbreaks of infection still occur in industrialized countries; the predominant species is S. sonnei. The purposes of this study are to investigate the epidemiological, clinical and microbiological features of an outbreak of Shigella dysenteriae caused by S. sonnei at Yu-Li Hua-Lien, Taiwan. Genes responsible for antimicrobial resistance in the clinical isolates were examined. Methods: An outbreak of bacillary dysentery caused by S. sonnei in 2 elementary schools at Yu-Li, Hua-Lien occurred in October, 2001, after one typhoon hit that area. The children admitted to Yu-Li Veteran Hospital were enrolled in this study. The clinical and microbiological data of the infected children were collected. We performed PCR, pulsed-field gel electrophoresis (PFGE), and plasmid analysis to further characterize the clinical isolates. Results: Altogether 47 children from two elementary schools admitted to Yu-Li Veteran Hospital were culture-positive for S. sonnei in this outbreak. Twenty-three children were asymptomatic. The symptoms and signs among the symptomatic children were fever (95.8%), diarrhea (75%), abdominal pain (66.7%), vomiting (50%), bloody stool (16.7%). The rate of resistance to ampicillin was 55.3%. Of note, 2 isolates obtained from 2 children of school A developed resistance during the course of treatment. All patients recovered without complications and follow-up stool cultures were negative after the last course of antibiotic treatment. 21 isolates were available from the outbreak of Hua-Lien for the performance of PFGE. The isolates from school A showed the same PFGE pattern (pattern 4a) except for two isolates; yet the PFGE pattern of the ampicillin non-susceptible isolates were identical to the susceptible ones. Isolates from school B showed another identical PFGE pattern (pattern 4) except for one isolate. CMY type AmpC beta-lactamase was responsible for ceftriaxone resistance in ceftriaxone-resistant isolates, and Southern blot hybridization confirmed the resistance gene was located on the plasmid. Conclusion: Shigellosis is still a public-health problem in some area of Taiwan. The clinical manifestations of shigellosis are variable. Antimicrobial resistance might develop during the course of treatment. Ceftriaxone-resistant gene was located on a plasmid, which might be responsible for the spread of resistance among isolates.