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.

After the first cases of a zoonotic outbreak are identified [39] , control measure sometimes consists of the culling of the entire flock or herd on the affected farm. Cullers are usually equipped with personal protective equipment and receive personal hygiene instructions, although it has been shown that such measures can reduce exposure, but are not fully protective [44, 45] . Secondary cases among contacts of cullers can also occur, as reported after a large outbreak of H7N7 Avian Influenza in Dutch poultry farms in 2003 [46] . After this outbreak, risk factors for the acquisition [39] and transmission [47] of an infection were 'clinical inspection of poultry in the area surrounding infected flocks' [39, 47] , and 'active culling during depopulation' [39] . A more quantitative relationship was reported by Whelan et al. during the large Q-fever outbreak in the Netherlands between 2007 and 2009 [48] . In cullers working on Q-fever infected goat farms, an exposure-response-like relationship between the 'total number of hours worked inside the farm perimeter' and 'working mostly inside stables' and the risk of seroconversion for C. burnetii markers was discovered [48] .