Considerable effort has been made to determine the prevalence of E. coli

O157 in cattle worldwide (Brazil: [17], Canada: [18], Denmark: [19], England: [20], Iran: [21], Netherlands: [22]; Norway: [23], Spain: [24], Sweden: [25], United States: [26]). Estimates of prevalence range from 0 to 71% of animals and 0 to 100% of herds [27]. Two of the world’s largest surveys of animal E. coli O157 prevalence were conducted in the past decade in Scotland. The first [28] estimated herd-level and animal-level prevalence for 952 farms throughout Scotland in a study funded by the Scottish Executive Environment and Rural Affairs Department (SEERAD) conducted from March 1998 to May 2000. Since then a second survey, funded by the Wellcome EPZ5676 price Foundation International Partnership Research Award in Veterinary Epidemiology (IPRAVE) was selleck chemicals conducted on a subsample of the 952 SEERAD farms, from February

2002 to February 2004. Data from the SEERAD and IPRAVE studies are presented in this paper. In Scotland, the first reported cases of human E. coli O157 infection were identified in 1984. Currently, Health Protection Scotland (HPS) conducts active, population based enhanced surveillance in close collaboration with the Scottish E. coli O157/VTEC Reference laboratory (SERL) [29]. Over the 10 year period 1998-2007, an annual average of 221 culture positive cases has been reported to HPS, which is an average annual rate of 4.28 cases per 100,000 population [30]. Rates in Scotland are generally higher than in most other Glutathione peroxidase United Kingdom, European and North

American countries [30–33]. A recent publication proposed a specific mechanism for the link between human infection and livestock carriage of E. coli O157 [34] which involved a subset of shedding animals known as super-shedders. Super-shedders are individuals who for a period yield more infectious organisms (here E. coli O157) than typical individuals of the same host species [34]. Shedding high concentrations of E. coli O157 has been proposed as a major contributor to cattle-to-cattle transmission [34–36] and possibly cattle-to-human transmission. Although little is known about super-shedders it has been shown that they have been associated with the presence of phage type (PT) 21/28 whereas non super-shedders are more likely to be associated with PT32 [37]. Recent evidence has shown PT21/28 to be associated with higher transmission in livestock when compared to PT32 [38]. PT21/28 is the most predominant phage type in both cattle [37] and human cases [39] whereas PT32 is a common phage type in cattle only [37]. In humans, PT21/28 is of particular concern because of its association with more severe morbidity. In the UK and Ireland (1997-2001), the mean risk of developing diarrhoea-associated HUS was significantly higher in children in Scotland infected with PT21/28 compared with other phage types [40].