By Ethan Covey
Although usually tied to meat consumption, an outbreak of Salmonella enterica serovar Typhimurium has been linked to the consumption of tofu.
Tofu has not been linked to previous nontyphoidal Salmonella outbreaks, and S. enterica serovar Typhimurium cases are typically tied to animal product consumption (MMWR Morb Mortal Wkly Rep 2023;72[32]:855-858).
“The study is significant as this is the first known Salmonella outbreak linked to the consumption of tofu,” a Public Health Ontario (PHO) spokesperson told Infectious Disease Special Edition. “Salmonella Typhimurium has been identified in soy products in some microbiological studies but not in any previously published outbreak reports.”
The outbreak affected 38 people in 10 Ontario public health districts located from May through mid-August 2021. Five patients were hospitalized, and no deaths were reported.
Among 30 patients who were interviewed, 63% reported eating vegetarian or vegan diets, and further investigation narrowed the focus to seasoned tofu, which was consumed at one of 11 restaurant franchise locations or one of three nonfranchise restaurant locations.
“Soy food products, including tofu, are uncommon vehicles for foodborne illnesses,” said the PHO spokesperson, who asked not to be named. “While we cannot rule out the possibility that this unusual pattern observed in the outbreak could be explained by an evolving pathogenicity in nontyphoidal Salmonella, it is possible that with the growing increase in the consumption of plant-based food, more people are consuming plant-based food such as tofu in more recent years.”
Further studies may help shed light on whether the outbreak was caused by an evolving pattern in the pathogenicity of the pathogen, and help determine the source of the contamination.
“From a food safety perspective, there are still key questions that would require additional investigations,” the PHO spokesperson said.
The source reported no relevant financial disclosures.