Livestock-associated MRSA ST398 carriage in pig slaughterhouse workers related to quantitative environmental exposure
- Maarten J Gilbert1,
- Marian E H Bos1,
- Birgitta Duim2,
- Bert A P Urlings3,4,
- Lourens Heres3,
- Jaap A Wagenaar2,5,
- Dick J J Heederik1,6
- 1Division of Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
- 2Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- 3VION Food Group, Eindhoven, The Netherlands
- 4Animal Sciences Group, Wageningen University, Wageningen, The Netherlands
- 5Central Veterinary Institute, Wageningen UR, Lelystad, The Netherlands
- 6Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
- Correspondence to Dr Marian E H Bos, Institute for Risk Assessment Sciences (IRAS), Utrecht University, PO BOX 80178, 3508 TD Utrecht, The Netherlands;
Contributors MJG, MEHB, BAPU, LH, JAW and DJJH were involved in conception and design of the study. MJG, MEHB and LH collected the samples and data. MJG, MEHB and DJJH cleaned and statistically analysed the data. MJG, MEHB, BD, JAW and DJJH interpreted the data. MJG and MEHB performed laboratory analyses. BD and JAW developed real-time PCR targeting ST398. MJG, MEHB, BD, JAW and DJJH interpreted the results of the laboratory analysis. MJG, MEHB, JAW and DJJH drafted the paper. MJG, MEHB, BD, BAPU, LH, JAW and DJJH revised the draft paper.
- Accepted 8 March 2012
- Published Online First 27 April 2012
Objectives To assess livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) carriage among workers in pig slaughterhouses and assess associated risk factors, including occupational exposure to LA-MRSA.
Methods A cross-sectional study in three Dutch pig slaughterhouses was undertaken. Nasal swabs of participants were taken. Nasal swabs and surface wipes, air and glove samples were screened for presence of methicillin-resistant Staphylococcus aureus (MRSA). MRSA was quantitatively determined on gloves and in air samples by culturing and real-time PCR.
Results 11 of 341 (3.2%) participants were identified as nasal MRSA carriers. MRSA-positive workers were predominantly found at the start of the slaughter process. Major risk factors for carriage were working in the lairage and working in the scalding and dehairing area. Most nasal isolates (73%) belonged to the LA-MRSA clone ST398. MRSA ST398-positive environmental samples were found throughout the slaughter process. A clear decrease was seen along the slaughterline in the number of MRSA-positive samples and in the MRSA amount per sample.
Conclusions This study showed that working in the lairage area or scalding and dehairing area were the major risk factors for MRSA carriage in pig slaughterhouse workers, while the overall prevalence of MRSA carriage is low. Occupational exposure to MRSA decreased along the slaughterline, and the risk of carriage showed a parallel decrease.
- MRSA carriage
- slaughterhouse workers
- exposure assessment
- preventive medicine
- risk assessment
- risk assessment
- retrospective exposure assessment
- lung function
- organic dusts
- animal workers
- occupational asthma
MJG and MEHB contributed equally.
Funding The BACTOPATH project was funded by NL Agency and the Dutch Product Board for Livestock and Meat (PVV).
Competing interests None declared.
Patient consent Obtained.
Ethics approval Ethics approval was provided by METC Utrecht.
Provenance and peer review Not commissioned; externally peer reviewed.