Listeriosis is a major public health concern associated with high hospitalization and mortality rates. The objective of this work was to summarize evidence on the associations between risk factors and sporadic cases by meta-analysing outcomes from currently published case-control studies. Suitable scientific articles were identified through systematic literature search, and subjected to a methodological quality assessment. From each study, odds-ratio (OR) measures as well as study characteristics such as population type, design, type of model and risk factor hierarchy were extracted. Mixed-effects meta-analysis models were adjusted by population type to appropriate data partitions.

Twelve primary studies investigating sporadic listeriosis conducted between 1985 and 2013 passed through a quality assessment stage. These studies provided 226 OR considered for meta-analysis.

According to the meta-analysis, the main risk factor for acquiring listeriosis is suffering from an immunocompromising disease. In relation to the food exposures, this meta-analysis confirmed known risk factors such as consumption of RTE dairy, seafood and processed meat and underlined new food vehicles as fruits and vegetables, recently involved in outbreaks. There were not enough data to appraise travel, animal-contact and person-to-person as transmission pathways for listeriosis. These results will allow refining the case-control studies in the aim of improving risk factors characterisation for listeriosis in the susceptible population.

李斯特菌病是与高住院率和高死亡率相关的主要公共卫生问题。这项工作的目的是通过对当前发表的病例对照研究的结果进行荟萃分析，总结风险因素与散发病例之间关联的证据。通过系统的文献检索确定合适的科学文章，并进行方法学质量评估。从每项研究中，提取了比值比（OR）以及研究特征，例如人口类型，设计，模型类型和风险因子等级。根据人群类型将混合效应荟萃分析模型调整为适当的数据分区。

在1985年至2013年之间进行的十二项散发性李斯特菌病调查研究已进入质量评估阶段。这些研究提供了226个OR进行荟萃分析。

根据荟萃分析，获得李斯特菌病的主要危险因素是患有免疫功能低下的疾病。关于食物暴露，这项荟萃分析证实了已知的风险因素，例如食用RTE乳制品，海鲜和加工的肉类，并强调了最近爆发的水果和蔬菜等新的食物媒介。没有足够的数据来评估旅行，动物接触和人与人之间的李斯特菌病传播途径。这些结果将有助于完善病例对照研究，以改善易感人群中李斯特菌病的危险因素特征。