Human–livestock contacts and their relationship to transmission of zoonotic pathogens, a systematic review of literature

Klous, Gijs; Huss, Anke; Heederik, Dick J.J.; Coutinho, Roel A.

In some instances, very brief exposure may be sufficient for transmission of micro-organisms, especially when the infectious dose of a pathogen is very low [88] . This was shown in Germany in a study focussing on LA-MRSA carriage among farmers and residents in an area with a high density of livestock farms. Farmers were mainly at risk when they had pig contact, but the authors also found that regular visits to farmse.g. to buy eggs or milkincreased the chance of becoming a LA-MRSA carrier among non-farm residents [89] . In Turkey, preparing freshly slaughtered sheep led to transmission of Orf virus during the feast of sacrifice, an Islamic tradition, among non-occupationally exposed people [90] . Visits to an agricultural fair in the US resulted in transmission of Swine Influenza between displayed pigs and human visitors [27] . Visitors of a pedagogical farm in France were reported to be infected with Q-fever [28] and gastrointestinal infections with VTEC O157 occurred on a farm open to the public in the UK [91] . VTEC O157 infections were also observed among 'holidaymakers', 'farm visitors', 'farming families' and 'farm workers' [92] . Still, the actual pathway of an infection was not specifically ascertained in most papers. This was illustrated by an outbreak of C. parvum among children camping on an adventure farm in the UK [93] .