Laboratory Research
Epidemiological and pathogenic features of a bacillary dysentery outbreak in a boarding school caused by Shigella sonneri
Zhaoqian Meng, Ran Duan, Ge Bu, Guoxia Guo, Liangzi Guo, Yunkai Hu
Published 2019-08-10
Cite as Chin J Epidemiol, 2019, 40(8): 988-991. DOI: 10.3760/cma.j.issn.0254-6450.2019.08.021
Abstract
ObjectiveTo investigate the etiologic and epidemiologic features of an infectious diarrhea outbreak in a boarding school in Fuyang city, Anhui province.
MethodsTraceability hypothesis of this study was tested according to the epidemiological characteristics of the cases. Feces, anal swabs, water samples and food residues related to the patients and chefs were collected for pathogen isolation and detection. Biochemical identification, virulence gene detection, drug susceptibility test, PFGE and multilocus sequence typing were performed.
ResultsThe incidence rate (3.41%) of different dormitory buildings within the water supply area by shallow wells was higher than that (0.98%) of the deep wells, with statistical significance (χ2=17.215, P<0.001). Sixteen strains belonged to the Shigella Sonneri family were isolated from the patient’s samples, and all carrying the ipaH gene. Seven strains belonged to sen and ial genes. Set1 gene that did not appear in all the 16 strains were highly resistant to ampicillin, tetracycline, compound xinnomine, cefazoline, cefotaxime, gentamicin, naphthidinic acid and streptomycin, including 9 strains to doxycycline. The pulse field pattern of the 16 strains of Shigella sonneri appeared the same, with the ST type as ST152.
ConclusionWhen combined data from the etiological and epidemiological investigation, it was confirmed that Shigella sonneri was the pathogen of this outbreak, and water from the shallow wells might be responsible for the source of infection.
Key words:
Shigella sonnei; Drug susceptibility test; Virulence genes
Contributor Information
Zhaoqian Meng
Fuyang Municipal Center for Disease Control and Prevention of Anhui Province, Fuyang 236000, China
Ran Duan
National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
Ge Bu
Fuyang Municipal Center for Disease Control and Prevention of Anhui Province, Fuyang 236000, China
Guoxia Guo
Fuyang Municipal Center for Disease Control and Prevention of Anhui Province, Fuyang 236000, China
Liangzi Guo
Fuyang Municipal Center for Disease Control and Prevention of Anhui Province, Fuyang 236000, China
Yunkai Hu
Fuyang Municipal Center for Disease Control and Prevention of Anhui Province, Fuyang 236000, China