Epidemiological and trace-back investigation and virulence factors analysis of an O139 cholera outbreak
- Author:
ZHANG Haibing
;
ZHAO Hongwei
;
DING Lijuan
- Publication Type:Other Types
- Keywords:
Vibrio cholerae;
O139 serotype;
turtle;
epidemiological survey
- From:
China Tropical Medicine
2025;25(3):371-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To analyze the epidemiological characteristics and infection pathways and virulence factors of one cholera outbreak in Fengxian District, Shanghai, China, in 2024, and to provide scientific basis for epidemic control and prevention. Methods Epidemiologic data of cases of one cholera outbreak in Fengxian District in 2024 were collected using on-site epidemiologic survey methods; RT-PCR nucleic acid testing and bacterial culture were applied to carry out pathogenicity testing of cases, close contacts, environment, and food samples; and the genome sequences of the strains were obtained using second-generation gene sequencing. Results The case was a 62-year-old woman, who presented to the doctor with diarrhea for 4 consecutive days, 4-5 times a day, with watery stools, which was not effectively relieved by self-administered medication. There was no history of traveling away from Shanghai for 5 days before the onset of the disease, and she was engaged in the preparation and delivery of food for rural banquets during the period. Vibrio cholerae O139 was detected in the anal swab sample of the case and the septic tank of the workplace on the 4th day after the onset of the disease; samples of turtle and links in the store selling turtle were cultured for Vibrio cholerae O139. The isolate carried several virulence-related genes such as ctxA, ctxB, HlyA, zot, rtxA, hapA, nanH, tdh, and T3SS. Comparison of the isolate with the O139 strain of cholera cluster within our country through the National Pathogenic Bacteria Recognition Network (NPBN) in recent years suggests that the closest environmental or aquatic animal isolate to the sequence of this strain is the turtle isolate uploaded at a place in Guangdong. Conclusion This outbreak was a disseminated outbreak caused by the case's contact with turtle contaminated with Vibrio cholerae O139, and early detection of enteric infectious diseases such as cholera can be achieved by relying on the outpatient enteric cholera surveillance network.
- Full text:202511191656042142220.Epidemiological and trace-back investigation and virulence factors analysis of an O139 cholera outbreak.pdf