Foodborne illness outbreaks grow as imported food increases

February 17, 2017

As the proportion of U.S. food imported from other countries increases, a recent analysis found the number of foodborne illness outbreaks associated with imported foods has also increased.

The study, “Outbreaks of Disease Associated with Food Imported into the United States, 1996-2014,” found that 19% of food consumed by Americans is now imported, including 97% of fish and shellfish, 50% of fresh fruits, and 20% of fresh vegetables. In total, where imported food was implicated, there were 195 outbreak investigations in the U.S. during the study period with 10,685 illnesses — including 1,017 hospitalizations and 19 deaths.

While the researchers view this a relatively small number, it has increased as both an absolute number and in proportion to the total number of outbreaks where the implicated food was identified and reported prior to 1996.

The researchers also found the pace of recalls due to contaminated imported food quickening, with just three import-related outbreaks occurring from 1996 to 2000 and 18 per year on average from 2009 to 2014. The most likely suspects of contamination when imported food was involved was in fish and produce. The most common agents reported in outbreaks were scombroid toxin (produced mostly from decayed fish) and Salmonella.

The researchers explain that aquatic animals were responsible for 55% of total outbreaks and 11% of outbreak-associated illnesses. Produce was responsible for 33% of outbreaks and 84% of outbreak-associated illnesses. Outbreaks attributed to produce had a median of 40 illnesses compared with a median of three in outbreaks attributed to aquatic animals. Most of the Salmonella outbreaks (77%) were associated with produce, including fruits (14), seeded vegetables (10), sprouts (6), nuts and seeds (5), spices (4), and herbs (1).

Furthermore, information was available on the region of origin for 177 (91%) outbreaks, with Latin America and the Caribbean the most common region implicated, followed by Asia. Overall, 31 countries were implicated, with Mexico having the most implications (42 outbreaks). Other countries associated with more than 10 outbreaks were Indonesia (17) and Canada (11).

Fish and shellfish were most commonly imported from Asia, which was responsible for 65% of outbreaks associated with fish or shellfish. Produce originated from all regions but was most commonly imported from Latin America and the Caribbean (64% of outbreaks associated with produce). In addition, all but one outbreak associated with dairy products involved products imported from Latin America and the Caribbean.

Outbreaks in this analysis were reported from 31 states, most commonly California, Florida and New York. Forty-three outbreaks (22%) were multistate outbreaks — reflecting the wide distribution of many imported foods.

The researcher explain that this data highlights the importance of having standard protocols for molecular characterization of isolates and systems for rapid traceability of implicated foods to their source. Newer tools like whole genome sequencing can also help to generate hypothetical transmission networks and in some instances facilitate traceback of foods to their origin.

In addition, the researchers write that new rules under the Food Safety Modernization Act, including the Preventive Controls Rule for Human Food, Produce Safety Rule, Foreign Supplier Verification Program, and Accreditation of Third Party Auditors, should help to strengthen the safety of imported foods by granting FDA enhanced authorities to require that imported foods meet the same safety standards as foods produced domestically.

For more information, click here.

Neogen is a leader in the food safety industry and offers a variety of products to detect foodborne bacteria, natural toxins, food allergens, drug residues, plant diseases and sanitation concerns. Neogen’s NeoSeek platform is a breakthrough pathogen detection system and identification service that provides next day, DNA-specific results for E. coli strains (STECs) and Salmonella identification.

Category: Food Safety