LAUSR

&NA; Livestock can carry extended‐spectrum beta‐lactamase (ESBL)‐producing Enterobacteriaceae, with blaCTX‐M‐1 being most prevalent. ESBL carriage in farmers is associated with ESBL carriage in animals, with direct animal‐human contact considered as the dominant route of transmission. However, inhalation of stable air might represent another route of transmission. We, therefore, quantified presence of blaCTX‐M group 1 genes (CTX‐M‐gr1) in dust and the association with CTX‐M‐gr1 carriage in pig farmers, family members and employees. We included 131 people living and/or working on 32 conventional Dutch pig production farms (farmers, family members and employees) during two sampling moments over a 12‐month interval. Human stool samples, rectal swabs from 60 pigs per farm, and 2–5 dust samples collected using an electrostatic dust collector (EDC) (as a proxy for presence of viable CTX‐M‐gr1 carrying bacteria in air) were obtained per farm. Presence of ESBL‐producing Escherichia Coli (E. coli) in stool samples and rectal swabs was determined by selective plating and CTX‐M‐gr1 was identified by PCR. Dust samples were analyzed directly by PCR for presence of CTX‐M‐gr1. Questionnaires were used to collect information on nature, intensity and duration of animal contact. Overall human prevalence of CTX‐M‐gr1 carriage was 3.6%. CTX‐M‐gr1 was detected in dust on 26% of the farms and in pigs on 35% of the farms, on at least one sampling moment. Human CTX‐M‐gr1 carriage and presence of CTX‐M‐gr1 in dust were associated univariately (OR=12.4, 95% CI=2.7–57.1). In multivariate analysis human CTX‐M‐gr1 carriage was associated with the number of working hours per week (OR=1.03, 95% CI=1.00–1.06), presence of CTX‐M‐gr1 carrying pigs on the farm (OR=7.4, 95% CI=1.1–49.7) and presence of CTX‐M‐gr1 in dust (OR=3.5, 95% CI=0.6–20.9). These results leave open the possibility of airborne CTX‐M‐gr1 transmission from animals to humans next to direct contact. HighlightsCTX‐M‐gr1 carriage in pig farmers and presence of CTX‐M‐gr1 in dust are associated.The number of CTX‐M‐gr1 positive human, pig and dust samples decreased over time.Air transmission of CTX‐M‐gr1 might be possible on pig farms.