Attribution of human infections with Shiga toxin‐producing Escherichia coli (STEC) to livestock sources and identification of source‐specific risk factors, The Netherlands (2010–2014)

Abstract

SummaryShiga toxin-producing Escherichia coli (STEC) is a zoonotic pathogen of public health concern whose sources and transmission routes are difficult to trace. Using a combined source attribution and case-control analysis, we determined the relative contri- 25.4%), pigs (mDM: 12.5%; mHM: 5.7%) and poultry (mDM: 2.7%; mHM: 3.1%), whereas the sources of the remaining 12.8% of cases could not be attributed. Of the top five O-serotypes infecting humans, O157, O26, O91 and O103 were mainly attributed to cattle (61%-75%) and O146 to small ruminants (71%-77%). Significant risk factors for human STEC infection as a whole were the consumption of beef, raw/undercooked meat or cured meat/cold cuts. For cattle-attributed STEC infections, specific risk factors were consuming raw meat spreads and beef. Consuming raw/ undercooked or minced meat were risk factors for STEC infections attributed to small ruminants. For STEC infections attributed to pigs, only consuming raw/undercooked meat was significant. Consuming minced meat, raw/undercooked meat or cured meat/ cold cuts were associated with poultry-attributed STEC infections. Consuming raw vegetables was protective for all STEC infections. We concluded that domestic ruminants account for approximately three-quarters of reported human STEC infections, whereas pigs and poultry play a minor role and that risk factors for human STEC infection vary according to the attributed source. K E Y W O R D Sanimal reservoirs, E. coli, risk factors, shiga toxin-producing Escherichia coli, source attribution, transmission routes

Attributable sources of community-acquired carriage of Escherichia coli containing β-lactam antibiotic resistance genes: a population-based modelling study

“…We used a commonly applied source attribution model for pathogens based on typing data, the modified Hald model, 22 with some adaptations for our study compared with its previous applications, for example, for Salmonella, 22,23 Campylobacter, 22 Listeria, 24 and Shiga toxinproducing E coli. 25 Our analysis was based on ESBL-EC and pAmpC-EC genes in the open community as the group to be attributed to the aforementioned human and non-human sources. Additionally, because ESBL-EC and pAmpC-EC transmission also occurs among people, 16,18 the open community was also set as a potential source of ESBL-EC and pAmpC-EC for the open community itself.…”

“…Genes only found in sources were kept in the model to preserve the within-source gene relative frequencies, as advised in previous studies. 22,25 To test our primary results, we did several validation analyses. The model uses the similarities of ESBL-EC and pAmpC-EC gene frequencies as anchor points for attribution, using prevalence and human exposure data as scaling factors and q i and a j to account for differential gene-specific and source-specific transmission efficiencies.…”

Enterohaemorrhagic and other Shiga toxin-producingEscherichia coli(STEC): Where are we now regarding diagnostics and control strategies?

“…STEC can colonize a wide range of animals and the majority of this bacterial population probably reside in asymptomatically colonized animal hosts. Using classical epidemiological studies, including outbreak and case–control analyses, and molecular epidemiological approaches, source attribution studies identify ruminants, especially cattle, as a major reservoir and the food chain as a significant transmission route (Mughini‐Gras et al., ; Pennington, ) as well as person‐to‐person spread (Garvey, Carroll, McNamara, & McKeown, ).…”

The role of parameterization in comparing source attribution models based on microbial subtyping for salmonellosis

“…Although being very data-intensive (Mangen et al, 2010), during the last years a Bayesian microbial subtyping attribution model published by Hald et al (2004) became increasingly popular and widely applied. This model, that we call 'Hald model' for short, was developed for attributing Salmonella cases in Denmark and has been adapted to attribute salmonellosis, for example in the United States (Guo et al, 2011), New Zealand (Mullner et al, 2009), Sweden (Wahlstrom, Andersson, Plym-Forshell, & Pires, 2011), France (David, Guillemot, et al, 2013), Italy , the Netherlands (Mughini-Gras & van Pelt, 2014;Mughini-Gras et al, 2017), the European Union (Pires, Knegt, & Hald, 2011) and Australia (Glass et al, 2016). Similar attempts were conducted for attributing Campylobacter (Mullner et al, 2009;Ranta et al, 2011) and Listeria monocytogenes (Little, Pires, Gillespie, Grant, & Nichols, 2010) cases.…”