Skip Navigation
Animal Feeding Operations & MRSA

animal feeding & MRSA

The incidence of methicillin-resistant Staphylococcus aureus (MRSA) in the region has increased dramatically over the past decade, with over 4,000 cases during this period. Recently, community-associated infections (CA-MRSA) have surpassed healthcare-associated infections (HA-MRSA) in incidence. Joan Casey, a doctoral student at Johns Hopkins, completed her PhD dissertation research on this topic. Our research group made several interesting and novel observations which are summarized in three published, peer-reviewed manuscripts. We found: 1) the incidence of CA-MRSA increased by over 30% per year while that of HA_MRSA increased by 5% per year; 2) CA-MRSA cases now exceed HA_MRSA cases; 3) aspects of both the farms on which animals were raised and the crop fields to which manure was applied were associated with increased risk of MRSA infection and 4) certain molecular subtypes not previously associated with these animal operations were associated with human MRSA infections. We are currently investigating whether these animal feeding operations cause other health impacts.


Casey JA, Shopsin B, Cosgrove SE, Curriero FC, Nachman KE, Rose H, Schwartz BS. Molecular characterization of MRSA infection and association with high-density livestock production in Pennsylvania, USA. Environ Health Perspect 2014 Feb 7, Epub ahead of print.

Casey JA and Schwartz BS. Swine livestock production as a risk factor for community associated MRSA in Pennsylvania. Alliance for the Prudent Use of Antibiotics (APUA) newsletter. 2013 Dec; 31(3): 9-12.

Casey JA, Curriero FC, Cosgrove SE, Nachman KE, Schwartz BS. High-density livestock Operations, crop field application of manure, and risk of community-associated methicillin-resistant Staphylococcus aureus infection in Pennsylvania. JAMA Internal Medicine 2013 Sep 13.

Casey JA, Stewart WF, Cosgrove SE, Pollak J, Schwartz BS. A population-based study of the epidemiology and clinical features of methicillin-resistant Staphylococcus aureus infection in Pennsylvania 2001-2010. Epidemiology & Infection 2013 Jun;141(6):1166-79.