NIOSHTIC-2 Publications Search

Assessment and mitigation of airborne transmission of methicillin-resistant Staphylococcus aureus in animal feeding operations and the outdoor environment.

Ferguson DD
Iowa City, IA: University of Iowa, 2012 Dec; :1-122
Methicillin-resistant Staphylococcus aureus (MRSA) was originally recognized as a hospital acquired infection. However, it is now recognized that MRSA infections are frequently acquired in the community and agricultural settings as well. As epidemiological studies and surveillance of MRSA continued over the past decade, agricultural sources of MRSA have also been recognized. Although direct person-to person transmission of MRSA has been recognized as a major known route of transmission, a preliminary study has shown that aerosol exposures may also be an important mechanism of transmission, both occupationally to workers inside animal feeding operations and environmentally via exhaust ventilation to the outside. In this study I aimed to 1) determine the concentration of viable MRSA inside and outside swine buildings known to be positive for MRSA, 2) determine the efficiency of the N-95 respirator for potentially protecting workers inside swine buildings, and 3) determine the efficiency of a biofilter unit for mitigating emissions of MRSA from a swine building. I hypothesize that remediation and control of airborne MRSA in animal feeding operations can be achieved by the appropriate use of N-95 respirators to protect workers and the addition of biofilters to the exhaust ventilation system to mitigate transmission of this emerging environmental contaminant to the outdoor environment. The results of the study indicate that aerosolized MRSA in the respirable size range can be detected inside a swine building and 215 m downwind of the swine building. Aim 2 results indicated that the N95 respirator was efficient at potentially protecting workers exposed to MRSA particles greater than 5 um but not as effective with MRSA particles less than 5 um. The results of aim 3 indicated that hardwood chips and western red cedar chips are efficient biofilter media for mitigating the emission of MRSA from a swine building. These studies showed that workers inside swine buildings and the outdoor environment can be potentially protected against the transmission of MRSA with a respiratory program which includes the use of N95 respirators and biofilters as mitigation control measures.
Agriculture; Agricultural-industry; Bacteria; Infectious-diseases; Health-care; Exposure-levels; Risk-factors; Animals; Livestock; Livestock-industry; Environmental-exposure; Airborne-particles; Biological-effects; Infection-control; Infectious-diseases; Epidemiology; Surveillance-programs; Aerosols; Aerosol-particles; Respirators; Respiratory-protection; Respiratory-protective-equipment; Pathology; Pathogens; Antibiotics
Publication Date
Document Type
Funding Type
Fiscal Year
Identifying No.
Source Name
Assessment and mitigation of airborne transmission of methicillin-resistant Staphylococcus aureus in animal feeding operations and the outdoor environment
Performing Organization
University of Iowa
Page last reviewed: November 13, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division