Outbreaks of virulent diarrheagenic Escherichia coli - are we in control?

In our view, opportunities to improve control of STEC outbreaks lie in early clinical suspicion for STEC infection, timely diagnosis of all STEC at the serotype-level and integrating molecular subtyping information into surveillance systems. Furthermore, conducting analytical studies that supplement patients' imperfect food history recall and performing, as an investigative element, product tracebacks, are pivotal but underutilized tools for successful epidemiologic identification of the suspected vehicle in foodborne outbreaks. As a corollary, these tools are amenable to tailor microbiological testing of suspected food.Please see related article: http://www.biomedcentral.com/1741-7015/10/12 webciteAmong diarrheagenic Escherichia coli, those producing Shiga toxin (synonym: Vero toxin), are the most virulent to date. These Shiga toxin-producing E. coli (STEC) can cause hemorrhagic colitis that may manifest as painful, grossly bloody diarrhea [1] as well as hemolytic uremic syndrome (HUS) - a potentially fatal thrombotic microangiopathy, typically affecting children (pathogenesis and treatment strategies are fully discussed in the accompanying commentary by Goldwater et al. [2]). The case-fatality ratio of STEC illness is dependent on the patients' age and the virulence profile of the infecting strain. It is less than 1% for STEC gastroenteritis [3]. For apparently sporadic STEC-associated HUS, the case-fatality ratio in the acute phase is between 2% and 5% [3,4], but it can be as high as 10% in outbreaks of the rare sorbitol-fermenting O157:H- STEC [5].Since their first description in 1977 [6], many (> 100) different STEC serotypes, a categorization based on O (somatic) and H (flagellar) antigens, have been associated with human disease. Of those, O157:H7 has the strongest association with HUS worldwide [7]. This serotype is the primary target for diagnosing human STEC infection in many countries due to its virulence and propensity to cause common source outbreaks co