广州市非伤寒沙门菌感染流行病学负担分析

评估广州市非伤寒沙门菌感染流行病学负担,提出食源性疾病监测策略。方法 在广州市6区设9家食源性疾病主动监测医院,调查12个月腹泻病例采样率、沙门菌检测率、实验室检测敏感度,进而推算全市医疗机构相应数据；在广州市3区开展人群腹泻随机抽样入户调查,调查腹泻病例就诊率；通过传染病报告信息管理系统获得监测医院和全市医疗机构沙门菌感染性腹泻报告率；利用食源性疾病流行病学负担金字塔模型,通过倍数校正和不确定性分析估计沙门菌感染实际发病数,比较食源性疾病主、被动监测数据用于疾病负担分析的优劣。结果 监测医院12个月腹泻病例平均采样率38.34%,沙门菌检测率28.24%,实验室检测敏感度87.5%,人群腹泻病例就诊率23.91%,沙门菌感染性腹泻报告率42.98%；全市医疗机构推算采样率38.34%,检测率28.24%,实验室检测敏感度47.5%,报告率20.94%,估计广州市沙门菌感染病例64 586例(95%CI:44 136～101 921),年发病率508.5/10万(95%CI:347.5～802.5/10万),全年全市被动报告病例仅171例,报告年发病率1.3/10万；经估算5岁以下年龄组(3 583.2/10万)年发病率最高,15～24岁年龄组(23.5/10万)最低。结论 首次验证疾病负担金字塔模型在我国食源性疾病负担研究领域的适用性；表明主动监测一定程度上提升了食源性疾病尤其是特定病原体感染采样率、检测率、实验室检测敏感度和报告率,有助于对负担作出更准确和积极有效的估计；结果提示广州市非伤寒沙门菌感染负担较重,5岁以下年龄组人群负担水平尤其显著。

Epidemiological burden of nontyphoidal Salmonella infection in Guangzhou

To evaluate the burden of nontyphoidal Salmonella infection in Guangzhou and provide information for strategies of foodborne diseases surveillance.MethodsBased on the active surveillance system established in nine hospitals from six districts, a 12-month population-based household survey in three districts, as well as national notifiable disease reporting system (NNDRS), attendance rates of patients with diarrhea, stool sampling rate, laboratory testing rate for Salmonella, sensitivity of testing method, and positive case reporting rate were calculated and adjusted by pyramid model ratio and uncertainty analysis to yield the burden ratio and make a comparison between active and passive surveillance. Then the local actual annual incidence of nontypoidal Salmonella infection was estimated and analyzed according to the foodborne diseases epidemiological burden pyramid model. ResultsThe average attendance rate of patients with diarrhea was 23.91%; stool sampling rate, laboratory testing rate for Salmonella, sensitivity of the stool culture method and positive case reporting rate of the active surveillance hospitals were 38.34%, 28.24%, 87.5% and 42.98% respectively, extrapolating rates of hospitals around the city as 38.34%, 28.24%, 47.5% and 20.94%. Accordingly, it was estimated that the actual annual incidence rate of nontyphoidal Salmonella infection was 508.5 cases (95%CI:347.5-802.5) per 100 000, with 64 586 (95%CI:44 136-101 921) as emerging cases, while the reported cases from NNDRS was only 171 and the annual incidence rate was 1.3 cases per 100 000. Among different age groups, the incidence of under 5 years was estimated as the highest (3 583.2 per 100 000), while age group from 15 to 24 years the lowest (23.5 per 100 000).ConclusionIt was the first time that the pyramid model was used on specific foodborne pathogen burden analysis in China, based on data from local surveys, indicating that active surveillance would help improve the stool sampling, laboratory test for Salmonella, sensitivity of the stool culture method, and positive case reporting, and the pyramid model would help gain effective and robust estimate of disease burden. According to the estimate, nontyphoidal Salmonella infection was a major public health problem in Guangzhou in terms of disease burden, which was higher than that of the U.S, with the highest incidence occurred in the age group younger than 5 years. The findings highlighted the necessity to carry out further investigations on risk factors and to implement effective intervention measures on Salmonella infection.