Epidemiology and Infection

Original Papers

Staphylococcus

Methicillin-resistant Staphylococcus aureus in people living and working in pig farms

I. V. F. VAN DEN BROEKa1 c1, B. A. G. L. VAN CLEEFa1, A. HAENENa1, E. M. BROENSa2a3, P. J. VAN DER WOLFa4, M. J. M. VAN DEN BROEKa5, X. W. HUIJSDENSa6, J. A. J. W. KLUYTMANSa7, A. W. VAN DE GIESSENa8 and E. W. TIEMERSMAa1

a1 Epidemiology & Surveillance Unit, Centre Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands

a2 Laboratory for Zoonoses and Environmental Microbiology, Centre Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands

a3 Quantitative Veterinary Epidemiology, WIAS, Wageningen University, The Netherlands

a4 Pig Health Department, Animal Health Service, Deventer, The Netherlands

a5 Food and Consumer Product Safety Authority Region East, Zutphen, The Netherlands

a6 Laboratory for Infectious Diseases and Screening, Centre Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands

a7 VU Medical Center, Amsterdam, The Netherlands; Amphia Hospital, Breda, The Netherlands

a8 Laboratory for Zoonoses and Environmental Microbiology, Centre Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands

SUMMARY

We compared the prevalence of human and animal methicillin-resistant Staphylococcus aureus (MRSA) at pig farms in The Netherlands, and related this to individual and farm-level characteristics. More than half of the farms investigated (28/50) had MRSA in pigs or stable dust and about one third (15/50) of person(s) were identified as MRSA carriers. Human carriage was found only on farms with MRSA-positive pigs or dust. MRSA strains in human samples were the same spa-type as found in pigs and all were not typable by pulsed-field gel electrophoresis (NT-MRSA). Multivariate analyses showed that risk factors for human MRSA carriage were: working in pig stables (OR 40, 95% CI 8–209) and the presence of sows and finishing pigs (OR 9, 95% CI 3–30). Veterinary sample collectors sampling the pigs showed transient MRSA carriage only during the day of the farm visit. Working in pig stables with MRSA-positive pigs poses a high risk for acquiring MRSA, increasingly so when contact with live pigs is more intensive or long lasting.

(Accepted September 17 2008)

(Online publication October 24 2008)

Correspondence:

c1 Author for correspondence: Dr I. V. F. van den Broek, RIVM-EPI, Mailbox 1/pb 75, 3720 BA, Bilthoven, The Netherlands. (Email: Ingrid.van.den.broek@rivm.nl)

Metrics