The remaining 16 solved enteric disease outbreaks were linked to animal contact, the majority of which (11) involved backyard poultry flock, causing 532 illnesses, 145 hospitalizations, and two deaths.

Leafy Greens, Seeded Vegetables Lead Foodborne Outbreaks, Illnesses

Vegetable row crops (all leafy greens), chicken, and dairy were the most frequent causes of solved foodborne illness outbreaks, with each linked to four outbreaks. STEC, Salmonella, and Listeria monocytogenes were the most implicated pathogens in outbreaks linked to vegetable row crops, chicken, and dairy, respectively.

Seeded vegetables (specifically, cucumbers and jalapenos) caused by far the most illnesses (754 across three outbreaks)—all due to Salmonella infection—which is five times higher than the next highest food category (root vegetables, 152 illnesses, all due to STEC).

Salmonella, Listeria Cause More Illnesses, Severe Outcomes

Salmonella was the leading cause of solved multistate foodborne illness outbreaks, linked to 13 outbreaks (45 percent), followed by Shiga toxin-producing Escherichia coli (STEC) with eight outbreaks (28 percent), Listeria monocytogenes with seven outbreaks (24 percent), and Campylobacter with one outbreak (3 percent). Salmonella also caused more illnesses per outbreak (median of 36, range 9–551) compared to outbreaks caused by STEC (median 20.5, range 8–104), Campylobacter (one outbreak with five illnesses), and L. monocytogenes (median 4 illnesses, range 2–65).

However, consistent with previous years, foodborne L. monocytogenes outbreaks were the most severe, with 93 percent of all patients hospitalized and a 13 percent mortality rate. Salmonella outbreaks had a 31 percent hospitalization rate and less than one percent mortality rate, STEC had a 41 percent hospitalization rate and one percent mortality rate, and 67 percent of people in the one investigated Campylobacter outbreak were hospitalized, with no deaths.