Who’s at risk for salmonella infection in Virginia?

Research helps Extension educators and food safety experts focus prevention efforts, improve detection, and reduce illness.

By Julie Shlisky

Salmonella infection is a common cause of foodborne illness. This disease-causing bacteria makes about 1 million people sick in the U.S. each year, including an estimated 38,000 in Virginia. Lost work time and medical bills account for more than $4 billion in losses each year. If you’ve endured foodborne illness, you remember how miserable it feels.

Despite efforts by industry and government, infection rates have not improved as expected. To better reduce those numbers, researchers need to understand who is getting sick — and why.

“Rates of salmonella infection depend on many factors, for example the health at the time of exposure, food-handling practices, and traits of the Salmonella strain,” said Rachel Cheng, an assistant professor in the Department of Food Science and Technology .

As part of her Capacity funded Hatch project, Cheng identifies salmonella subtypes making Virginians sick. Since some strains are more severe, drug-resistant, or easily transmitted, experts could target education that would reduce certain risks and prevent future cases.

Cheng’s team analyzed data from over 11,000 cases reported in Virginia. Researchers confirmed a pattern seen nationwide – children younger than 4 are much more likely to become infected. They also found that types of salmonella making people sick were associated with where they lived, suggesting germs were spreading locally and not from statewide food contamination.

Working with Associate Extension Specialist Lester Schonberger and additional seed grant funding, Cheng’s team conducted a statewide survey to assess parents and caregiver’s beliefs and habits that could affect risk of illness caused by salmonella. The survey revealed knowledge gaps, including an unawareness that young children were at higher risk of contracting foodborne illness. Many caregivers didn’t know where to find reliable information.

Recognizing knowledge gaps lets educators develop targeted campaigns to improve food safety, reduce infections, and better protect families.

“We can do more targeted Extension work in those areas,” Schonberger said. “And with the help of a graduate student we are developing factsheets and presentations for Extension agents and master food volunteers to use.”

Another way to reduce illness and economic loss is to improve technology to detect potential contamination before foodborne illness occurs. Cheng also works on a USDA-funded project testing food screening technology using filters to capture pathogens that cause foodborne illness in foods.

Along with researchers Yifan Cheng and Monica Ponder, new detection methods are applied that screen larger amounts for more concentrated samples. Greater volumes screened improve chances of catching contaminated food before it reaches consumers. Quicker results also prevent unnecessary food waste and reduce costs for producers.

Cheng’s lab also leads a National Needs Fellowship program alongside Food Science and Technology investigators Yifan Cheng, Haibo Huang, and Lester Schonberger, to recruit and train graduate students in biomanufacturing. In collaboration with Extension faculty, the fellowship provides hands-on research experience that prepares future leaders to protect the food supply and reduce food waste through intentional science education.  

To learn more about this story, contact Julie Shlisky at juliesb@vt.edu.