A School Outbreak of Shigella sonnei Infection in China: Clinical Features, Antibiotic Susceptibility and Molecular Epidemiology.

ABSTRACT

Objective: To describe the clinical features of infection, and the antibiotic susceptibility of epidemic strains, and investigate plasmid maps and integrons of the isolates from an outbreak of Shigella sonnei infection at an elementary school in southwest China. Study design: Cross-sectional study. Setting: An elementary school and five hospitals in Chengdu in southwest China. Results: There were 1,134 students in the school. 937 (82.6%) students had signs and symptoms. Of the 568 (60.6%, 568/937) hospitalized students, 93.3% 86.8%, 72.4%, and 28.9% of the hospitalized patients had diarrhea, fever, abdominal pain, and vomiting, respectively. S. sonnei strains were isolated from the stool samples of 36.0% (337/937) students. All of the outbreak isolates had the same high-level antimicrobial resistance and plasmid profiles, which were different from that of sporadic strains. All the outbreak S. sonnei isolates were positive for the integrin gene and contained class 2 integron; however, two outbreak isolates contained class 1 and class 2 integrons. Conclusions: Diarrhea, fever, and abdominal pain were the three most common clinical manifestations observed in patients infected with S. sonnei. High-level antibiotic resistance was observed among Shigella species.