According to the CDC, as of September 20, 2012, a total of 15 persons infected with the outbreak strain of Listeria monocytogenes have been reported from 12 states and the District of Columbia.

The number of ill persons identified in each state is as follows: California (1), Colorado (1), District of Columbia (1), Maryland (3), Minnesota (1), Nebraska (1), New Jersey (1), New Mexico (1), New York (1), Ohio (1), Pennsylvania (1), Virginia (1), and Washington (1).

All 15 ill persons were hospitalized. Three deaths have been reported. Listeriosis contributed to at least one of these deaths.

Collaborative investigation efforts of local, state, and federal public health and regulatory agencies indicate that imported ricotta salata cheese is the likely source of this outbreak. On September 10, 2012, Forever Cheese, Inc. voluntarily recalled one lot of Marte brand Frescolina ricotta salata cheese due to Listeria monocytogenes contamination. Peterson Company also is recalling Ricotta Salata Frescolina brand cheese that came from its supplier Forever Cheese of Long Island City, NY.