The non-profit organization said this is leading to outbreaks that could alert health officials to safety failures in the food chain and generate recalls of contaminated products being missed.
“Outbreak Alert! 2015” examined outbreaks of foodborne disease from 2004 to 2013 reported to the Centers for Disease Control and Prevention (CDC).
CSPI said rapid diagnostic tests bypass laboratory-based public health surveillance systems and budget constraints on local public health departments impact reporting.
However, it added the foodborne illness surveillance system is improving.
Findings by category
Produce was linked to more outbreaks and illnesses than any other category and Salmonella was the second-leading cause of illnesses sourced to this food group.
This category was top for solved outbreaks, with 643 (19%), and 20,456 illnesses (24% of total illnesses).
Seafood was responsible for the second-most outbreaks (541), but relatively few illnesses due to the small size of an average event (5,173 illnesses, about 10 illnesses per outbreak).
Outbreaks associated with USDA-regulated foods include poultry (372 outbreaks and 11,580 illnesses), beef (249 outbreaks and 5,452 illnesses), and pork (153 outbreaks and 4,001 illnesses).
The annual number of outbreaks with beef, produce, seafood, pork, and poultry declined across the decade, but reports in most categories increased since 2009.
“The larger outbreaks attributed to produce are often linked to a contaminant from a farm or distribution center,” said CSPI.
“Produce safety standards—including adequate hygienic infrastructure for farmworkers—and good agricultural practices that FDA issued in November 2015 should help prevent on-farm contamination.”
The report cited reoccurring outbreaks from 2012-15 of cyclosporiasis from cilantro grown in Puebla, Mexico, Salmonella Newport in cucumbers in 2014 and Listeria-contaminated cantaloupes in 2011.
CSPI said pound for pound, fruit and vegetables are among the safest foods while seafood was the most hazardous.
“You are twice as likely to get sick from eating a serving of chicken as from eating a serving of vegetables,” said David Plunkett, CSPI senior food safety attorney, co-author of the report.
“The data support improving the safety of our produce supply but don’t support eating less fruits and vegetables, which provide valuable nutrients.”
Of the 9,625 outbreaks responsible for 193,754 illnesses, 3,485 responsible for 86,121 illnesses were solved with an identified food and contaminant.
Over the 10-year period, less than 40% were solved for both food vehicle and contaminant.
Solved outbreaks are important to develop risk-based interventions and design effective hazard controls, said the group.
Many health departments are underfunded, understaffed, and overwhelmed by the volume of illness reports, it added.
Since 2009, the average number of foodborne illness outbreaks, as reported by CDC, has decreased by about a third, compared to the six preceding years.
In the last four years, from 2010 to 2013, the number of outbreaks CDC reported varied little from year to year.
The study found the foodborne illness surveillance system is improving, but more needs to be done, Plunkett said.
“Far too many outbreaks are not getting solved quickly or are going unsolved altogether, thereby forgoing opportunities to implement corrective measures. We need a better surveillance system.”
Among USDA-regulated products, Salmonella species were most common in pork and poultry products, and E. coli O157:H7 in beef.
Staphylococcus aureus was associated with pork more than other products and norovirus and C. perfringens were evenly distributed across food categories.
The most commonly identified causes in FDA-regulated foods were Norovirus and Salmonella spp. in produce; scombrotoxin and ciguatoxin in seafood; Campylobacter in dairy; and Salmonella in eggs.
CSPI recommended Congress fund programs to integrate the foodborne illness surveillance system it directed the CDC to establish in the Food Safety Modernization Act.
The group is supported by subscribers to Nutrition Action Healthletter and foundation grants. It does not accept government or industry funding.