Q-177. Workers’ Exposure to Airborne Pathogens in Swine Confinement Buildings of Eastern Canada According to the Production System

V. Létourneau1, B. Nehmé2, A. Mériaux3, A. Letellier4, D. Massé5, C. Duchaine3,1;
1Univ. Laval, Sainte-Foy, QC, CANADA, 2CHUL, Sainte-Foy, QC, CANADA, 3Hôpital Laval, Sainte-Foy, QC, CANADA, 4Univ. de Montréal, Sainte-Hyacinthe, QC, CANADA, 5Agriculture and Agri-Food Canada, Lennoxville, QC, CANADA.

Background. The trend in Eastern Canadian swine production is toward totally enclosed, well-insulated buildings with a controlled environment to provide adequate ambient temperature, humidity and air flow rate inside the building. Over the last 20 years, as the production increased, new buildings using different manure management systems (conventional, sawdust litter, source separation of urine and faeces) emerged. This study aimed to thoroughly characterize the bioaerosols (including aerosolized manure pathogens) within swine barns using various production systems. Methods. Aerosolized mesophilic bacteria and pathogens were collected with Andersen 6 stages and AGI-30 in 18 swine confinement buildings using different production systems. Mesophilic bacteria, Campylobacter, C.perfringens, Enterococcus, E.coli and Y.enterocolitica were quantified by culture and PCR on extracted DNA from AGI-30 solutions. Temperature and relative humidity were monitored with a psychrometer. Results. Barns with sawdust litter were the coolest buildings (p<0.0001) and were more contaminated by airborne culturable mesophilic bacteria than buildings without litter (p<0.01). No difference was observed between the barns when total bacteria were quantified by universal EUB16S PCR. C.perfringens, Enterococcus and E.coli were respectively recovered up to 103, 105 and 101 CFU/m3 by culture. Culturable Y.enterocolitica were occasionally found in few aerosols. Airborne culturable Enterococcus concentrations were correlated to culturable mesophilic bacteria (p<0.01). Campylobacter concentrations reached 107 16s rDNA/m3 in one building. Conclusion. While there was no significant difference in total aerosolized bacteria and pathogens concentrations among the different production systems investigated, higher culturable concentrations of aerosolized mesophilic bacteria, Enterococcus and E.coli were present in sawdust litter barns. The lower temperature and the presence of nutriments-rich organic matter in the sawdust could explain the higher rate of bacteria survival to aerosolization and sampling inside buildings with litter.