Angelo K M, Conrad A R, Saupe A, Dragoo H, West N, Sorenson A, Barnes A, Doyle M, Beal J, Jackson K A, Stroika S, Tarr C, Kucerova Z, Lance S, Gould L H, Wise M, Jackson B R
Centers for Disease Control and Prevention,Atlanta,GA,USA.
Minnesota Department of Health,St. Paul,MN,USA.
Epidemiol Infect. 2017 Apr;145(5):848-856. doi: 10.1017/S0950268816003083. Epub 2017 Jan 9.
Whole apples have not been previously implicated in outbreaks of foodborne bacterial illness. We investigated a nationwide listeriosis outbreak associated with caramel apples. We defined an outbreak-associated case as an infection with one or both of two outbreak strains of Listeria monocytogenes highly related by whole-genome multilocus sequence typing (wgMLST) from 1 October 2014 to 1 February 2015. Single-interviewer open-ended interviews identified the source. Outbreak-associated cases were compared with non-outbreak-associated cases and traceback and environmental investigations were performed. We identified 35 outbreak-associated cases in 12 states; 34 (97%) were hospitalized and seven (20%) died. Outbreak-associated ill persons were more likely to have eaten commercially produced, prepackaged caramel apples (odds ratio 326·7, 95% confidence interval 32·2-3314). Environmental samples from the grower's packing facility and distribution-chain whole apples yielded isolates highly related to outbreak isolates by wgMLST. This outbreak highlights the importance of minimizing produce contamination with L. monocytogenes. Investigators should perform single-interviewer open-ended interviews when a food is not readily identified.
此前，完整苹果未曾被认为与食源性细菌性疾病的暴发有关。我们调查了一起与焦糖苹果相关的全国性李斯特菌病暴发事件。我们将暴发相关病例定义为在2014年10月1日至2015年2月1日期间感染了通过全基因组多位点序列分型（wgMLST）高度相关的两种单核细胞增生李斯特菌暴发菌株中的一种或两种的感染病例。通过单一访谈者开放式访谈确定源头。将暴发相关病例与非暴发相关病例进行比较，并开展溯源和环境调查。我们在12个州确定了35例暴发相关病例；34例（97%）住院治疗，7例（20%）死亡。暴发相关的患病者更有可能食用了商业生产的预包装焦糖苹果（比值比326.7，95%置信区间32.2 - 3314）。来自种植者包装设施和供应链完整苹果的环境样本经wgMLST检测，分离出的菌株与暴发分离株高度相关。此次暴发凸显了尽量减少单核细胞增生李斯特菌对农产品污染的重要性。当不易确定某种食物为传染源时，调查人员应进行单一访谈者开放式访谈。
