Risk factors for sporadic Yersinia enterocolitica infections: a systematic review and meta-analysis

Yersinia enterocolotica is an important causative agent of diarrheal illness. A systematic review and meta-analysis of case-control studies were performed to determine the main risk factors associated with sporadic Y. enterocolitica infections. Suitable scientific articles published between 1987 and 2017 were identified through a systematic literature search and subject to methodological quality assessment. From each study, odds ratios (OR) were extracted or calculated, as well as study characteristics such as population type, design, type of model used and risk factor categorization. Mixed-effects meta-analytical models were adjusted by population type to appropriate data partitions. From 807 identified references, the quality assessment stage was passed by 14 case-control studies focusing on sporadic Y. enterocolitica infections which provided 165 ORs for meta-analysis. All studies considered Y. enterocolitica as the cause of sporadic infections and are mainly located in Europe.

The meta-analysis identified host-specifics factors, animal and food exposures as significant risk factors. The meta-analysis confirms the predominant role of the pig reservoir. The occupational contact with pigs and the consumption of pork meat are significantly associated with sporadic Y. enterocolitica infections occurrence. The consumption of raw or undercooked pork meat is also a very important risk factor. Untreated drinking water was also identified as risk factor. Further studies with other enteropathogenic Yersinia species, especially Y. pseudotuberculosis, and/or from other continents would help to refine conclusions of the meta-analysis of the risk factors of yersiniosis.