Genomic Sequencing Reveals: The Primary Sources of Human Salmonella Infections in Europe
A new study published in the Journal of Infection utilizes Whole Genome Sequencing (WGS) to identify the sources of Salmonella infections across Europe. The research aimed to assess the relative contribution of various reservoirs (livestock, environmental sources, etc.) to human infections caused by the five most prevalent Salmonella serovars in Europe: S. Typhimurium, S. Enteritidis, S. Infantis, S. Newport, and S. Derby.
The researchers analyzed WGS data from 10 European countries, comprising 3,548 Salmonella isolates obtained from both clinical (human) and non-clinical sources (animals, food, and the environment).
The study identified the primary reservoirs contributing to human infection for each serovar:
Salmonella Typhimurium: The primary source was pigs (63.8%), followed by dogs (7.1%) and horses/donkeys (6.0%).
Salmonella Enteritidis: The main source was laying hens/table eggs (68.8%), followed by broilers (19.7%).
Salmonella Infantis: The primary source was broilers (56.1%), followed by pigs (14.4%).
Salmonella Newport: Attributed sources were diverse, including reptiles (28.1%), cattle (25.9%), and laying hens (17.8%).
Salmonella Derby: The primary source was pigs (62.9%), followed by turkeys (22.7%).
The Impact of International Trade A significant finding of the study is that a substantial portion of human morbidity is attributed to sources originating in countries other than the patient's country of residence. This highlights the role of international food trade as a major transmission vector. For instance, a high percentage of S. Enteritidis cases across various countries was attributed to sources originating in Poland.
