The death toll has risen to 15 in the deadliest foodborne outbreak in the United States in more than a decade.
Dozens of others are ill from eating listeria-contaminated cantaloupes shipped by a Colorado-based farm company.
Of the 15 deaths, five were in New Mexico, three were in Colorado, two were in Texas, and there was one each in Kansas, Maryland, Missouri, Nebraska and Oklahoma.
The US Centers for Disease Control and Prevention says 84 people in 19 states are infected.
The CDC said on Wednesday it expected more infections and possibly deaths in the outbreak because listeria had a long incubation period, with symptoms sometimes not showing up until two months after people consume listeria-laced foods.
On Friday, California-based True Leaf Farms recalled almost 15,000 bags of chopped romaine lettuce that may be contaminated with listeria, although no illnesses have been reported and officials said the incident had no direct link to the deadly outbreak.