Washington D.C. — Data from the Centers for Disease Control and Prevention released today demonstrates little progress on reducing illnesses from the major foodborne pathogens. The new data shows increases in foodborne illnesses associated with several reported pathogens, and while CDC attributes some of those increases to changes in diagnostic testing and reporting, it has not ruled out an actual uptick in infections.
“This CDC report shows that unsafe food continues to make millions of Americans sick each year. The data underscores the urgent need for policy reforms to address Salmonella and other foodborne pathogens, particularly in meat and poultry,” said the Director of CFA’s Food Policy Institute, Thomas Gremillion. “We know how to make food safer, we just need the political will to move forward.”
The CDC data shows large increases in the number of confirmed Shiga toxin–producing Escherichia coli (STEC), Yersinia, and Cryptosporidium infections. CDC notes that these increases likely reflect changes in reporting methodologies and diagnostic testing, but for pathogens less affected by these changes, including Salmonella, Listeria and Vibrio, infection rates also went up.
This year’s report highlights a methodological revision in how the agency tracks foodborne illness trends. For years, public health officials sent clinical samples to labs, where technicians would grow or “culture” the bacteria from the sample to produce an isolate. New techniques for identifying pathogens, referred to as culture-independent diagnostic tests, or CIDTs, are increasingly performed directly on stool specimens and other samples. Sometimes, samples with a positive CIDT pathogen test are sent to a lab to be cultured and further analyzed, but often they are not.
Until this year, CDC did not count infections diagnosed with CIDT as “confirmed infections” unless they were also confirmed using the older, culture-based techniques. The use of CIDTs has increased, however, and so the agency has changed its methodology. This change likely accounts for a significant part of increases reported in some infection rates, such as that of Campylobacter, for which nearly 30% of reported cases were exclusively identified by CIDT last year, as compared to 16% in 2015.
Citing the change in methodology, CDC maintains that “comparisons of the 2016 data with data from previous years may not accurately reflect trends,” and that infection estimates “this year and in years past are accurate, but cannot be directly compared.” At the same time, the agency highlights a decline in reported infections from a single pathogen serotype, Salmonella Typhimurium, and suggests it “may be due to regulatory action to reduce Salmonella contamination in poultry.” Overall, reported Salmonella infections attributable to all serotypes, even excluding those confirmed with only CIDT, increased in 2016.
CDC told consumer advocates in a briefing prior to release of the study that it will not produce its normal “report card” comparing the 2016 infection estimates to the Healthy People 2020 Objectives for reducing foodborne illness infections. The omission is concerning to advocates that worry it may signal a reluctance to continue measuring progress toward public health goals.
“Technological change is one of many factors that complicates foodborne illness surveillance,” said Gremillion. “Despite the uncertainty, however, we must set goals and attempt to determine whether we are moving towards them, taking advantage of all the resources available. CDC has said that the agencies are developing new tools to continue to track progress toward reducing foodborne illness, and we look forward to learning how those will be applied.”
Contact: Thomas Gremillion, 202-939-1010
The Consumer Federation of America is an association of more than 250 non-profit consumer groups that, since 1968, has sought to advance the consumer interest through research, education, and advocacy.