Improving occupational health surveillance for enteric infections

Enteric pathogens with a livestock reservoir pose a unique risk to people in occupations with regular contact with animals. However, public health surveillance of occupational exposures is inadequate, with surveillance for occupation typically focusing on the risk of transmission and the need for worker exclusion, rather than workplace exposures. To improve surveillance for occupational zoonoses, the Colorado Integrated Food Safety Center of Excellence convened a group of subject matter experts who developed a set of variables on occupation, industry, and exposures, which were integrated into Colorado's surveillance system in 2017. We evaluated the quality and completeness of these new occupational fields for interviewed cases with laboratory-confirmed zoonotic infections and compared occupations to cases with a non-zoonotic infection (Shigella) and to employment data from the Bureau of Labor Statistics.

From March 2017 through December 2019, 3668 domestically acquired, laboratory-confirmed sporadic infections of Campylobacter, Cryptosporidium, Shiga toxin-producing Escherichia coli, and non-typhoidal Salmonella among individuals ≥14 years of age were interviewed by public health. We found asking explicitly about occupational exposure risks and focusing on animal exposures, improved data quality and accuracy. Of the cases who stated that they were employed, 262 (13%) reported working in an occupation with regular animal exposure, and 254 (14%) reported an industry with regular animal exposure. Cases with an animal exposure occupation were more likely to be male and live in a rural or frontier county compared to other occupations. All occupations with regular animal contact were reported at a higher frequency than among Shigella cases or the general population.

Public health efforts, both in occupational health and communicable disease sectors, should be made to improve surveillance for enteric zoonoses and identify opportunities for prevention strategies.