Workers on the front line: pathogen exposures and injuries in swine slaughter and processing

Industrialization of food-animal production has public health consequences that can directly affect workers and others involved in food-animal production. Slaughterhouse workers work in close contact with live animals, wastes, blood/carcasses, and may be among the most intensively exposed to many pathogens carried by animals. Pathogens carried by animals in industrialized production systems may have been selected for antimicrobial resistance, as a consequence of use of subtherapeutic concentrations of antibiotics. Another potential health concern among processing plant workers is injury. Processing plant work often involves repetitive tasks at high speed or work with sharp tools or around dangerous materials including the product itself (bones). These conditions can lead to increased risk of injury.

To study factors associated with Staphylococcus aureus exposure, specifically drug-resistant forms, we conducted a cross-sectional study of workers of the largest hog slaughterhouse and processing plant in the United States, located in Tar Heel, North Carolina. We conducted interviews in English and Spanish to collect information on demographics, occupational history, availability and use of protective equipment, recent health history (including infections and use of antibiotics), work related injuries, contact with animals, and diet Each participant provided a nasal swab to determine exposure to S. aureus. Swabs were cultured and the presence of S. aureus was confirmed. All S. aureus isolates were subjected to antibiotic-resistance testing.

We enrolled 164 workers, 63 of their household members, and a reference group of 111 community members (total n=336). Sixteen isolates were positive for methicillin-resistant S. aureus (MRSA) identified phenotypically (4.8%). Workers had the highest prevalence of MRSA (5.6%), followed by their household members (4.8%), and community referents (3.6%). Prevalent carpal tunnel syndrome was reported by 11% of processing plant workers, compared with 2% and 4% of household members and community members, respectively. Conversely, prevalence of lacerations was highest among household members. Approximately, 74% of workers reported that there are parts of his/her body that hurt from their job at the end of the workday in contrast with 33% and 43% of household and community members. Implications and public health recommendations of this study will be shared during this presentation.