Occupational Distribution of Campylobacteriosis and Salmonellosis Cases — Maryland, Ohio and Virginia, 2014

BACKGROUND: Campylobacter and Salmonella are leading causes of bacterial gastroenteritis in the United States with >1 million cases annually. These pathogens are primarily transmitted through consumption of contaminated food, but animal-to-human or human-to-human transmission can also occur. Occupational transmission has been reported, but patterns of disease by occupation have seldom been explored. In 2013, the Occupational Safety and Health Administration (OSHA) identified 63 campylobacteriosis cases at a poultry processing plant during a 42 month period. The OSHA investigation shed light on the importance of tracking occupational trends in current disease surveillance systems. We analyzed campylobacteriosis and salmonellosis case reports from 3 states to describe their occupational distribution and identify potential high risk occupations.

METHODS:  We obtained reports for confirmed, probable, and suspect campylobacteriosis and salmonellosis cases in 2014 among Maryland, Ohio and Virginia residents ≥16 years old from the state notifiable diseases surveillance systems. We abstracted occupational information from free-text fields then assigned a 2-digit Standard Occupational Classification code to each employed case. The American Community Survey was used to estimate the employed civilian population. We calculated risk ratios (RR) and 95% confidence intervals (CI) for associations between each occupational group and each disease, contrasting each group with all other occupations.

RESULTS:  Of 2,977 campylobacteriosis and 2,259 salmonellosis cases, 973 (33%) and 797 (35%) were employed and had codable occupation, respectively. Farming, fishing, and forestry occupations (RR: 10.0 [CI: 7.0–14.4] and 3.2 [CI: 1.6–6.4]) and healthcare/technical occupations (RR: 1.5 [CI: 1.2–1.9] and 2.0 [CI: 1.6–2.5]) were at increased risk for both campylobacteriosis and salmonellosis. The food preparation/serving-related occupations (RR: 1.6 [CI: 1.2–2.0]) and personal care/service occupations (RR: 1.5 [CI: 1.1–2.1]) were also at higher risk for salmonellosis. Forty-one poultry processing plant workers with campylobacteriosis were noted in three different occupation categories, and 4 poultry processing plant workers were found among salmonellosis cases.

CONCLUSIONS:  Workers in agriculture, healthcare, food, and personal care occupations appear at increased risk of enteric infection. Poultry processing plant workers are at higher risk of Campylobacter infection because of possible exposure to pathogens in the workplace. Clinicians should consider campylobacteriosis or salmonellosis among these workers with classic symptoms. Targeting education and prevention strategies, including disease awareness and proper hygiene techniques at work, to high risk groups could help reduce disease. Collecting occupational information in disease surveillance systems provides a better understanding of the extent of occupationally-acquired diseases to protect workers’ health.