Though the incidence of foodborne illnesses has held steady over the past several years, a surveillance system geared toward tracking the diseases found that those involving Escherichia coli O157 and certain Salmonella subtypes have been falling over the past decade, which experts say parallels decreased contamination in poultry and ground beef.
Infections involving some Salmonella subtypes, however, are on the rise, with some of them from nonfood sources, such as contact with animals.
Of subtyped Salmonella isolates in 2017, the five most common were Enteritidis, Typhimurium, Newport, Javiana, and I 4,[5],12:i:-, a variant of Typhimurium. For 2017, the incidence of Heidelberg was 65% lower than from 2006 to 2008, with a similar decrease for Typhimurium over the same period.

