More illnesses are expected in the listeria outbreak linked to Boar's Head deli meat, warns a food safety attorney.

A prominent food safety lawyer has warned that more illnesses are likely and called for a congressional investigation into Boar's Head after deli meat produced at one of the company's plants was linked to a multistate listeria outbreak.

The outbreak, which began in July, has resulted in at least 57 hospitalizations and nine deaths across 18 states, according to the Centers for Disease Control and Prevention (CDC). On August 28, the CDC reported six new deaths, marking the first fatalities in New Mexico, New York, South Carolina (2), and Tennessee. Seattle-based food safety attorney Bill Marler noted that more illnesses and possibly more deaths could occur, as listeria's incubation period can last over two months, meaning individuals who consumed contaminated deli meat in July might still develop symptoms.

The CDC's investigation identified listeria contamination in meats sliced at deli counters, including Boar's Head liverwurst, which sickened consumers. In response, Boar's Head expanded its recall to include all products produced at its Jarratt, Virginia facility. This week, inspection reports from the USDA's Food Safety and Inspection Service revealed that inspectors had found insects, mold, and mildew at the plant over the 12 months before it was voluntarily shut down due to the outbreak.