Investigation Details

Posted October 8, 2021

October 8, 2021

CDC, public health and regulatory officials in several states, and the U.S. Food and Drug Administration (FDA) are collecting different types of data to investigate a multistate outbreak of Salmonella Thompson infections linked to seafood.

Epidemiologic, laboratory, and traceback data show that this outbreak is linked to seafood distributed by Northeast Seafood Products of Denver, Colorado.

Epidemiologic Data

As of October 7, 2021, 102 people infected with the outbreak strain of Salmonella Thompson have been reported from 14 states (see map).  The majority of sick people are either Colorado residents or reported traveling to Colorado in the week before they got sick. Only two people did not report travel to Colorado in the week before they got sick. Illnesses started on dates ranging from May 11, 2021, to September 7, 2021 (see timeline).

Sick people range in age from less than 1 to 85 years, with a median age of 39, and 53% are female. Of 89 people with information available, 19 have been hospitalized, and no deaths have been reported.

The true number of sick people in an outbreak is likely much higher than the number reported, and the outbreak may not be limited to the states with known illnesses. This is because many people recover without medical care and are not tested for Salmonella. In addition, recent illnesses may not yet be reported as it usually takes 3 to 4 weeks to determine if a sick person is part of an outbreak.

State and local public health officials are interviewing people about the foods they ate in the week before they got sick. Among 62 people interviewed, 51 (82%) reported eating seafood. This percentage is significantly higher than the 35% of respondents from the FoodNet Population Survey who reported eating seafood in the prior week. Sick people reported eating a variety of seafood both raw as sushi and cooked.

Laboratory and Traceback Data

Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak. CDC PulseNet manages a national database of DNA fingerprints of bacteria that cause foodborne illnesses. DNA fingerprinting is performed on bacteria using a method called whole genome sequencing (WGS). For this outbreak, WGS showed that bacteria from sick people’s samples are closely related genetically. This suggests that people in this outbreak got sick from eating the same food.

Colorado state health officials and FDA traced the source of seafood served at restaurants and sold at grocery stores in Colorado where sick people ate or shopped. FDA determined that Northeast Seafood Products of Denver, Colorado, was the supplier of seafood to most of these locations.

During an FDA inspection of the Northeast Seafood Products facility, FDA collected environmental samples and identified the outbreak strain of Salmonella Thompson in the facility.

Testing of three sick people’s samples using standard antibiotic susceptibility testing methods by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory showed no resistance. WGS analysis of bacteria from 92 sick people’s samples did not predict resistance to any antibiotics. One person’s sample was predicted to be resistant to tetracycline. Most people with Salmonella illness recover without antibiotics. However, if antibiotics are needed, this resistance is unlikely to affect the choice of antibiotic used to treat most people.

Public Health Actions

On October 8, 2021, Northeast Seafood Products of Denver, Colorado, recalledexternal icon certain types of seafood processed at their facility since October 7, 2021, including Haddock, Monkfish, Bone-in Trout, Grouper, Red Snapper, Red Rock Cod, Ocean Perch, Pacific Cod, Halibut, Coho Salmon, Atlantic Salmon Portions, Lane Snapper, Tilapia, All Natural Salmon Fillet, Pacific Sole, and Farm Raised Striped Bass.

Previous Updates

Since the notice on August 24, 2021, CDC combined the outbreak of Salmonella Infantis infections and the outbreak of Salmonella Typhimurium infections into one investigation. As of August 26, the data for the two outbreaks will be reported together. No new cases have been reported since the previous notice.

Epidemiologic data show that Fratelli Beretta brand prepackaged Uncured Antipasto trays may be contaminated with Salmonella and may be making people sick.

Epidemiologic Data

As of August 25, 2021, a total of 36 people infected with either the Salmonella Infantis (13) or Salmonella Typhimurium (23) strain have been reported from 17 states (see map). Illnesses started on dates ranging from May 9, 2021, to July 27, 2021 (see timeline).

The true number of sick people in the outbreaks is likely much higher than the number reported, and the outbreaks may not be limited to the states with known illnesses. This is because many infected people recover without medical care and are not tested for Salmonella. In addition, recent illnesses may not yet be reported as it usually takes 3 to 4 weeks to determine if a sick person is part of an outbreak.

State and local public health officials interviewed people about the foods they ate in the week before they got sick. Officials also obtained sick people’s shopper records with their consent.

Of the 25 people with information, 22 (88%) reported eating a variety of Italian-Style meats. Among 15 people who remembered the specific product or had shopper card records showing a purchase, 14 had Fratelli Beretta brand prepackaged Uncured Antipasto trays.

Public Health Actions

CDC is advising people not to eat Fratelli Beretta brand prepackaged Uncured Antipasto trays with “best by” dates on or before February 11, 2022. This does not include Italian-style meats sliced at a deli. The investigation is ongoing to determine if additional products are linked to illness.