我国2010－2014年不同城乡类型地区细菌性腹泻病原谱的流行特征

Etiology of bacterial diarrhea in large cities, mid-sized/small cities and rural areas of China

目的 了解我国不同城乡类型地区细菌性腹泻病原谱流行特征。方法 基于2010－2014年我国17省份腹泻症候群感染性腹泻病原学监测。收集门/急诊因急性腹泻就诊病例，采集粪便标本，并进行包括基本人口学信息、临床症状特征等个案调查。对粪便标本进行17种常见致泻细菌病原体的病原学检测。按就诊医院类别将病例分为传统农村、中小城镇/城乡过渡带、大型城市3种类型，比较其病原体阳性率及病原谱构成差异。应用非条件logistic回归分析，比较3种类型病例感染的风险。结果 共纳入传统农村病例5 138例、中小城镇/城乡过渡带病例13 683例、大型城市病例9 253例，3种类型地区病例病原体阳性率城乡差异最大的为福氏志贺菌（阳性率依次为5.81%、2.78%、0.46%）和嗜水气单胞菌（阳性率依次为2.14%、0.96%、0.48%）。中小城镇/城乡过渡带、传统农村相对于大型城市病例感染各种细菌风险差异最大的为福氏志贺菌［OR值及其95% CI分别为6.481（4.666-9.002）、11.304（8.018-15.938）］和嗜水气单胞菌［OR值及其95% CI分别为1.992（1.401-2.832）、4.083（2.833-5.884）］。细菌病原谱中致泻性大肠埃希菌、沙门菌的构成比随城市化程度的提高而增加，志贺菌、嗜水气单胞菌则随城市化程度的提高而降低。志贺菌属血清群构成中大型城市以宋内志贺菌为主（60.00%），传统农村以福氏志贺菌为主（77.37%）。结论 我国不同城镇化水平地区细菌性腹泻病原谱流行特征存在明显差异，其中以福氏志贺菌和嗜水气单胞菌的差异最为显著。

Objective To understand the etiological characteristics of bacterial diarrhea in different areas, including large cities, mid-sized/small cities and rural area, in China. Methods A cross-sectional surveillance was conducted in 17 provinces of China from 2010 to 2014. The acute diarrhea outpatients were selected from clinics or hospitals in large cities, mid-sized/small cities, including rural-urban fringe zones, and rural areas. The demographical and clinical characteristics of the patients were collected by using questionnaire, and stool samples were taken from them for laboratory detection of 17 kinds of bacteria. The differences in pathogen positive rates （PPR） and pathogen spectrum across the cases from three-type areas were compared. The different infection risk in different cases were analyzed with unconditional logistic regression model. Results In our study, we enrolled 9 253 cases from large cities, 5 138 cases from rural areas and 13 683 cases from mid-sized/small cites. The pathogen with largest differences in infection rate across the three-type areas was Shigella （S.） flexneri （rural area：5.81%, mid-sized/small city：2.78%, large city：0.46%）, followed by Aeromonas （A.） hydrophila （rural area：2.14%, mid-sized/small city：0.96%, large city：0.48%）. Compared with cases in large cities, the cases in mid-sized/small cities and rural areas had higher infection risks for S. flexneri （mid-sized/small city：OR=6.481, 95% CI：4.666-9.002, rural area：OR=11.304, 95% CI：8.018-15.938） and A. hydrophila （mid-sized/small city：OR=1.992, 95% CI：1.401-2.832, rural area：OR=4.083, 95% CI：2.833-5.884）. The constituent ratio of diarrheagenic Escherichia coli and Salmonella increased with the urbanization development, while the ratios of Shigella and A. hydrophila had an opposite trend. S. sonnei （60.00%） was the predominant serogroup of Shigella in urban infections, while S. flexneri （77.37%） was the predominant serogroup in rural infections. Conclusion The differences in pathogen spectrum of bacterial diarrhea were obvious across large cities, mid-sized/small cities and rural areas in China, especially the differences in the infection rates of S. flexneri and A. hydrophila.