Social ecological determinants of occupational zoonotic disease exposure on Colorado dairy farms

Abstract

The presence of zoonotic pathogens in dairy farms is a known risk for people that work and live in these settings. People who work or live on a farm, farm visitors, service providers, and veterinarians are the most at risks of zoonotic infections. Dairy cattle operations represent a working environment with a high risk of exposure to zoonotic pathogens. The prevention of zoonotic diseases in animal-human interfaces can be challenging. Due to the complexity of the social ecological system, and it requires comprehensive, integrative, and culturally compelling interventions. It has been demonstrated that the behavior of the person at risk can affect their exposure to infectious agents. As demonstrated in other settings, the implementation of consistent and robust preventive measures can change the behavior of persons at risk and success-fully decrease exposure to risk factors. One of the host factors that affect exposure to human infectious diseases is the behavior of the people at risk. The SEM is a theory-based framework that has been used to scientifically explore the complex and interactive personal and environmental factors that affect people's preventive behaviors in specific settings. In general, the aim of epidemiological studies on infectious diseases using the SEM framework is to inform the development or improvement of comprehensive and compelling intervention strategies that directly target the behavior change process at different levels of influence. In this research, we conducted several research activities using the Social Ecological Model (SEM) approach to expand our understanding of host and environmental factors that affect the exposure of zoonotic diseases as work hazards. In the first research chapter (chapter 2) we proposed an SEM with potential factors affecting the preventive behavior of people at risk of zoonotic diseases in dairy farms. In the next chapter, we use this model to build an instrument that measures SE factors for workers of dairy farms and provide sources of validity for that instrument. And in the last research chapter (chapter 4), we identify that self-efficacy and negative workplace perceptions are risk factors of Salmonella Dublin exposure (OR=1.43 [CI 1.11-2.22] & 1.22 [CI 1.02-1.53] respectively) and that knowledge and positive management perceptions were protective factors (OR = 0.90 [CI 0.79-1.00] & 0.91 [CI 0.82-1.00] respectively). Perception of supervisors and coworkers is a protective factor of Campylobacter exposure (OR=0.89 [CI 0.79-0.98]). Based on our observations, a supporting organizational environment, with supervisors and coworkers as deliverers of accurate safety information, and with increased knowledge and understanding of the potential risks and consequences of zoonotic diseases would help to reduce the occupational exposure of zoonotic disease in these farms.