An investigation of bacillary dysentery outbreaks in three schools in Ankang / 中国学校卫生

ABSTRACT

Objective@#To investigate risk factors and epidemiological characteristics of bacillary dysentery outbreaks in three schools, and to provide scientific basis for the prevention and control of the epidemic in the future.@*Methods@#Case definition was established. All suspected, possible and confirmed cases of all students and faculty members from 3 schools (A, B, C) were selected for epidemiological investigation. Control group was used for case-control analysis, and relevant samples were collected for laboratory testing.@*Results@#A total of 132 cases were found in 3 schools, all of which were from students, with the incidence rate of 17.74%. The morbidity in kindergarten A was 20.00%, in center primary school B it was 21.74%, and in junior middle school C it was 11.61%. Cohort studies and casecontrol studies suggested that schools are exposed places and that washing hands with raw water in schools was possible risk factor [OR(95%CI) =4.50(1.01-20.11)]. Nine stool samples were tested in laboratory, among which 8 were positive for Shigella(88.99%), and Shigella was detected in the end nodes of school s pipeline network, the water samples from canteen bucket, and the floor drains of sewer pipe.@*Conclusion@#The bacillary dysentery outbreaks in 3 schools was caused by Shigella, which may be due to fecal contamination of domestic water in 3 schools before the start of the school year. It is suggested to strengthen the management of centralized water supply and construction in rural areas, intensify the supervision at all levels, and sanitation and disinfection before school opens at all levels.