In November 2022, CDC announced an outbreak of 16 people infected with an indistinguishable strain of Listeria reported from 6 states. Sick people’s samples were collected from April 17, 2021, to September 29, 2022.

Sick people range in age from 38 to 92 years, with a median age of 74, and 62% are male. Of 13 people with ethnicity information available, 11 are of Eastern European background or speak Russian. Of 14 people with information available, 13 have been hospitalized. One person got sick during their pregnancy, resulting in pregnancy loss. Additionally, one death has been reported from Maryland.

Of the 12 people interviewed, 11 reported eating meat or cheese from deli counters. Among seven sick people in New York, five bought sliced deli meat or cheese from at least one location of NetCost Market, a grocery store chain that sells international foods. Sick people from other states purchased deli meats or cheeses from other delis.

Investigators do not believe that NetCost Market delis are the only source of illnesses because some sick people in the outbreak did not shop at a NetCost Market. A contaminated food likely introduced the outbreak strain of Listeria into delis in multiple states.

In 2021, health officials in New York state and New York City found the outbreak strain of Listeria in several environmental and food samples:

• Environmental samples from a NetCost Market deli in Brooklyn
• Several open packages of mortadella and ham that were sliced at the same NetCost Market deli in Brooklyn
• Sliced salami that a sick person bought from a NetCost Market deli in Staten Island

NetCost Market voluntarily closed the deli temporarily in Brooklyn after New York officials notified them about the sampling results. NetCost Market performed a deep cleaning and then reopened the deli in Brooklyn after further environmental testing did not identify Listeria.

In September 2022, the outbreak strain was found at the same Brooklyn NetCost Market deli; however, the most recent illness with NetCost Market exposure was in October 2021. After a deep cleaning, additional environmental testing did not identify Listeria in the deli.

CDC closed the investigation on March 29, 2023.