E. coli are common bacteria and part of the normal flora of the GI tract. Some strains, including the Shiga toxin-producing E. coli (STEC) are able to produce a toxin (Shiga toxin), which can lead to serious human illnesses from mild diarrhea to life threatening conditions, such as hemolytic uremic syndrome (HUS). A report from the CDC shows that non-O157 STEC infections are more common than illnesses caused by E. coli O157:H7. A review of records for non-O157 STEC isolates forwarded by state public health labs to the CDC between 1983-2002 showed that six serogroups: O26, O45, O103, O111, O121, and O145, of the 61 serogroups identified accounted for 71% of the isolates recovered in the USA. In Europe a recent outbreak of STEC O104 infected approximately 4,000 people, led to over 800 cases of HUS, and caused the death of about 45 people. Other STEC serogroups, including STEC O104,O91, O113, O55, O118, O165, O128, and O8 also are an important cause of illness in the U.S. and in other countries, and public health authorities are monitoring for illness caused by these STEC serogroups. Transmission of STEC infection mainly occurs through contaminated food or water, and from contact with animals. Various types of animals, in particular cattle and other ruminants, can be healthy carriers of human-pathogenic STEC. During processing, fecal contamination of the carcass or transfer of bacteria found on the animal hide to the carcass can facilitate transmission of STEC into the food supply. Preventing the threats by all Shiga toxin producing E. coli (STEC) will reduce the cost of illness and death. According to the USDA Economic Research Service, during 2009 there were 73,480 cases due to E. coli O157:H7 costing $478 million, the cost of acute and chronic illness due to the non-O157 has not been calculated. The USDA Economic Research Service has also estimated the cost due to E. coli O157:H7 to be $488 million during 2010, while the cost of acute and chronic illness due to the non-O157 has not yet been reported. However, based on CDCs estimated cases of 31,229 on the non-O157 STEC from all sources, each case costs $6652 and it totals to $208 million. There are additional costs such as long-term health effects; price paid by the food or foodservice industries to issue a recall, dispose of product, and by public health agencies that have to investigate the outbreaks; PR campaign to restore a company's reputation, and the after-effects that a major crisis can have on sales for the whole industry. In 1994, the USDA-FSIS declared E. coli O157:H7 an adulterant in beef products, and on September 2011 E. coli serogroups O26, O45, O103, O111, O121, and O145 (top 6 non-O157 serogroups) were declared as adulterants on raw, non-intact beef products or components in the same manner as E. coli O157:H7. The USDA-FSIS performs a verification sampling program to test for these pathogens in samples collected from federally inspected establishments and retail stores. The testing protocol mandated by the USDA-FSIS is described in the USDA-FSIS, MLG Chapter 5B.03 "Detection and Isolation of non-O157 Shiga-Toxin Producing Escherichia coli Strains (STEC) from Meat Products"
