A salmonella outbreak linked to ground beef resulted in at least six hospitalizations across four states, according to the Centers for Disease Control and Prevention (CDC).

In an investigation notice published on Tuesday, the agency reported illness in 16 people across New York, New Jersey, Massachusetts and Connecticut, six of whom had to be hospitalized. There have been no deaths associated with the outbreak thus far, but the CDC warned that the true number of sick is likely much higher than those currently known and the impact radius may be larger than the four states identified as of July 24.

While investigators are still working to narrow down the primary source of the outbreak, ground beef was the only common food reported by those who became sick, specifically 80% lean ground beef purchased from ShopRite stores in Connecticut, New Jersey and New York.

A timeline provided by the CDC notes that illnesses associated with this rash of salmonella occurred between the dates of April 27 to June 16, 2023.

No recalls have been issued yet as the CDC continues to investigate.

Further investigation details specified that more recent incidents of illness may not yet be known, as it typically takes three to four weeks to determine if an individual has become sick as part of an outbreak. It is also common for people who contract salmonella to recover on their own without seeing a doctor, meaning some of those who were impacted were likely never tested and therefore never reported.

A representative for Wakefern Food Corp, the parent company of ShopRite, provided a statement via email that read in part:

“It is important to note that nine of the reported 16 cases purchased ground beef at different ShopRites and the source of the remaining seven cases has not been determined. The CDC’s investigation is ongoing and the USDA has not recommended a recall. Ground beef currently available at ShopRite is likely not impacted based on current epidemiological data.”