Date of Degree
PhD (Doctor of Philosophy)
Occupational and Environmental Health
Kelley J. Donham
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 setting 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 e. 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 N95 respirator at protecting workers inside swine buildings, and 3) determine the efficiency of a biofilter unit at 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 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 protecting workers exposed to MRSA particles greater than 5 μm but not as effective with MRSA particles less than 5 μm. 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 protected against the transmission of MRSA with a respiratory program which includes the use of N95 respirators and biofilters as mitigation control measures.
Copyright 2012 Dwight Deon Ferguson
Ferguson, Dwight Deon. "Assessment and mitigation of airborne transmission of methicillin-resistant Staphylococcus Aureus in animal feeding operations and the outdoor environment." dissertation, University of Iowa, 2012.