An E. coli O157:H7 outbreak tied to a nationwide recall of mechanically tenderized steaks is now linked to 21 illnesses in 16 states, according to public health officials.

Oklahoma-based National Steak and Poultry (NSP) announced last week it was initiating a recall of processed steak products after the Centers for Disease Control and Prevention (CDC) and the U.S. Department of Agriculture’s (USDA’s) Food Safety and Inspection Service (FSIS) identified a cluster of E. coli O157:H7 illnesses.

According to the FSIS release, the outbreak is linked to illness in 6 states: Colorado, Iowa, Kansas, Michigan, South Dakota, and Washington, but a CDC spokeswoman confirmed this morning that 16 states are reporting E. coli cases tied to the outbreak.

FSIS’s initial release also indicates that the product was distributed to restaurants across the country. According to NSP the product was distributed to Moe’s Southwest Grill, Carino’s Italian Grill, and KRM restaurants located primarily in the 6 states initially connected to the outbreak.

Neither the CDC nor FSIS has released a complete list of states involved in the outbreak. In response to several inquiries by Food Safety News, CDC officials deferred to the USDA and USDA officials said further questions about the outbreak should be directed to CDC.

There are 10 states with illnesses connected to the outbreak that have yet to be named.

According to a Food Safety News survey of state public health departments, Colorado has one confirmed case from November, which did not result in hospitalization.  A woman from Washington state fell ill while visiting Nebraska and is now recovering after hospitalization.

Iowa and Kansas health departments each confirmed one illness tied to the outbreak, and South Dakota officials reported two illnesses tied to undisclosed restaurants.  Public health officials in Michigan have yet to confirm the number of illnesses tied to the outbreak, though FSIS confirmed there are illnesses linked to the outbreak in the state.

FSIS also has not yet released a complete list of retail establishments that received the recalled meat.

NSP recalled over 25 different products. According to FSIS, all involved products bear an “EST. 6010T” establishment label and are labeled with packaging dates “10/12/2009,” “10/13/2009,” “10/14/2009,” or “10/21/2009.”

Most of the illnesses appear to have occurred later in November.

Mechanically tenderizing, otherwise known as blade- or needle-tenderizing, can drive potentially harmful bacteria to the center of steaks, which may not be cooked to adequate temperatures by consumers or restaurants.  The USDA currently does not require labeling mechanically tenderized steaks.

According to NSP, the recall is the company’s first in nearly 30 years of business.