Risk of Swine Influenza Virus Spillover at the Human-Swine Interface - a Scoping Review.

Objectives: We conducted this scoping review to describe the factors that influence the risk of spillover of Swine Influenza Virus (SIV) at various human-swine interfaces. Methods: We used the PubMed and EMBASE databases to identify relevant articles published until February 2024. We included cross-sectional, case-control, cohort, randomized controlled trials (RCTs), and ecological studies. Two authors screened the titles, abstracts, and full texts. The extracted details were presented in tables and figures. Results: Among the 55 studies, the majority were conducted in the United States (n = 27) and published after 2015 (n = 30). Occupational risk factors were the most commonly reported (n = 14), followed by lack of biosecurity measures (n = 10). We classified the identified risk factors into two broad categories: (1) risk factors that influence the transmission of SIV among swine and from swine to human, and (2) risk factors associated with the type of human-swine interfaces. Conclusion: Vaccination, biosecurity measures, and surveillance systems at human-swine interfaces effectively reduce swine influenza transmission. These strategies can be tailored to specific risk factors in common interaction settings.