Risk factors for subsp persistence in broiler-chicken flocks on Reunion Island.

This study was conducted to identify the main risk factors for spp. persistence in broiler flocks in Reunion Island. Seventy broiler farms were surveyed from March 2016 to June 2018. Samples of fresh droppings were collected using gauze socks, and a questionnaire was completed with the farmers. Persistence was defined as an infection with the same serovar before and after cleaning and disinfection (C/D) of poultry houses. spp. was found to persist on 27% of the farms. Cleaning concrete surrounding areas (OR = 0.23) and disinfecting silos (OR = 0.17) reduced the risk of pathogen persistence. An analysis of infections of pests found in the vicinity of the farms confirmed their role in the persistence of spp. Fifteen percent of the pests were infected and the presence of mealworms in poultry litter (OR = 6.69) was found to increase the risk of spp. persistence. We conclude that improved cleaning-disinfection, sanitary preventive measures and pest control in the poultry sector are needed to avoid the persistence of spp. on broiler farms.