A scoping study and systematic review-meta-analyses (SR-MAs) were conducted to evaluate the effectiveness of various interventions for Salmonella in broiler chicken, from grow-out farm to secondary processing. The resulting information was used to inform a quantitative exposure assessment (QEA) comparing various control options within the context of broiler chicken production in Ontario, Canada. Multiple scenarios, including use of two separate on-farm interventions (CF3 competitive exclusion culture and a 2% lactose water additive), a package of processing interventions (a sodium hydroxide scald water disinfectant, a chlorinated post-evisceration spray, a trisodium phosphate pre-chill spray and chlorinated immersion chilling) a package consisting of these farm and processing interventions and a hypothetical scenario (reductions in between-flock prevalence and post-transport concentration), were simulated and compared to a baseline scenario. The package of on-farm and processing interventions was the most effective in achieving relative reductions (compared to baseline with no interventions) in the concentration and prevalence of Salmonella by the end of chilling ranging from 89·94% to 99·87% and 43·88% to 87·78%, respectively. Contaminated carcasses entering defeathering, reductions in concentration due to scalding and post-evisceration washing, and the potential for cross-contamination during chilling had the largest influence on the model outcomes under the current assumptions. Scoping study provided a transparent process for mapping out and selecting promising interventions, while SR-MA was useful for generating more precise and robust intervention effect estimates for QEA. Realization of the full potential of these methods was hampered by low methodological soundness and reporting of primary research in this area.

Ethnic disparities in chlamydia infections in The Netherlands were assessed, in order to compare two definitions of ethnicity: ethnicity based on country of birth and self-defined ethnicity. Chlamydia positivity in persons aged 16–29 years was investigated using data from the first round of the Chlamydia Screening Implementation (CSI, 2008–2009) and surveillance data from STI centres (2009). Logistic regression modelling showed that being an immigrant was associated with chlamydia positivity in both CSI [adjusted odds ratio (aOR) 2·3, 95% confidence interval (CI) 2·0–2·6] and STI centres (aOR 1·4, 95% CI 1·3–1·5). In both settings, 60% of immigrants defined themselves as Dutch. Despite the difference, classification by self-defined ethnicity resulted in similar associations between (non-Dutch) ethnicity and chlamydia positivity. However, ethnicity based on country of birth explained variation in chlamydia positivity better, and is objective and constant over time and therefore more useful for identifying young persons at higher risk for chlamydia infection.