According to the results of a study recently published by the CDC, the incidence of dangerous and under-reported non-O157 E. coli infection is on the rise. E. coli is the term given to a large family of bacteria. Within that family, E. coli O157:H7 has been recognized as pathogenic to humans. As a result, E. coli O157:H7 is a reportable disease in the U.S. The dangerous pathogen is credited with more than 70,000 illnesses, over 2,000 hospitalizations and 61 deaths each year.
This may only be half the story. There is mounting evidence that other non-O157 strains of E. coli are responsible for a significant numbers of illnesses in the U.S. These other strains, referred to as non O157 STECs, or shiga-toxin producing Escherichia coli, cause illness just like E. coli O157:H7, but are currently under-reported, and, as a result, under-regulated.
The study, conducted by a team of scientists lead by Sarah Lathrop, consisted of a review of data collected in New Mexico from 2004 to 2007. The results revealed that non-O157 STEC present a significant threat to public health:
The data collected by New Mexico’s FoodNet surveillance network indicate that sporadic STEC cases increased substantially from 2004 through 2007. Reports of STEC O157 infection doubled from 7 to 14 from 2004 to 2006 but dropped to 9 in 2007. However, the number of non-O157 STEC cases continued to climb and accounted for most of the increase in overall STEC rates in New Mexico during this time, similar to rates in Connecticut.
The study also noted that non-O157 STEC made up a majority of all of STEC infections identified: “Non-O157 STEC infections ranged from 52% to 74% of all Shiga toxin–positive cases diagnosed each year and 64% of all identified STEC cases."
Information indicating that Non-O157 STECs might make up half, or more, of all STEC infection, is consistent with previously reported results from Europe.
What does this mean? It means that we are likely tracking and responding to only a fraction of actual STEC illness in the U.S. To adequately protect the population, non-O157 STEC needs to be treated like the equally dangerous, and apparently equally common O157:H7 strain.