Microbial Risk Analysis最新文献

{"title":"Characterization of the transfer probability of Salmonella ser. Typhimurium between pork and a cutting knife in an experimental model","authors":"Eduardo de Freitas Costa ,&nbsp;Claudia Navarrete Rivas ,&nbsp;Vanessa Bielefeld Leotti ,&nbsp;Marisa Cardoso ,&nbsp;Luis Gustavo Corbellini","doi":"10.1016/j.mran.2022.100203","DOIUrl":"10.1016/j.mran.2022.100203","url":null,"abstract":"<div><p>Cross-contamination is an important event for bacterial transfer throughout the pork production chain. In Brazil, <em>Salmonella</em> sp. is the most relevant hazard in the pork industry, and further knowledge concerning its contamination is essential for in-depth risk assessments. Thus, we aimed to assess the transfer probability of <em>Salmonella</em> sp. between a knife and pork in a domestic kitchen scenario to provide parametrization for incorporating transfer of <em>Salmonella</em> sp. in risk assessment models. To estimate <em>Salmonella</em> Typhimuium transfer rates between contaminated pork and a knife blade during cutting, 23 independent experiments were performed. A Bayesian inference was utilized to determine the transfer probability, capturing the uncertainty generated in the transfer probability experiments. The mean transfer probability was 0.03 for knife to pork [0.029; 0.032] 95% credible interval (CrI) and 0.0042 for pork to knife [0.0041; 0.0043] 95% CrI. The probabilistic estimate of the transfer probability of <em>Salmonella</em> sp. during pork cutting gives insights on a relevant parameter for the consumer phase of the pork production industry in Brazil, allowing for enhanced risk assessment models.</p></div>","PeriodicalId":48593,"journal":{"name":"Microbial Risk Analysis","volume":"21 ","pages":"Article 100203"},"PeriodicalIF":2.8,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352352222000032/pdfft?md5=d2ce85724b7743148da8376b4ac790e5&pid=1-s2.0-S2352352222000032-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46984941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbiological profile and modeling the survival of Escherichia coli ATCC 25922 in Amlou: A traditional Moroccan spread food","authors":"Youssef Ezzaky ,&nbsp;Mariem Zanzan ,&nbsp;Fouad Achemchem ,&nbsp;Antonio Valero ,&nbsp;Fatima Hamadi","doi":"10.1016/j.mran.2022.100216","DOIUrl":"10.1016/j.mran.2022.100216","url":null,"abstract":"<div><p>This study was carried out to assess the bacteriological profile and to model the combined effects of physicochemical parameters on <em>Escherichia coli</em> ATCC 25922 levels in <em>Amlou</em>, a typical Moroccan traditional spread food made with argan oil, sweet almonds, and honey or sugar. Microbiological analyses of the samples (<em>n</em><span><span> = 44), collected from different traditional producers, included total viable count (TVC), total </span>coliforms (TC), fecal coliforms (FC), </span><em>E. coli,</em><span> lactic acid bacteria (LAB), yeasts and molds (YM), </span><span><em>Staphylococcus aureus</em><span><em>, Salmonella, and </em><em>Listeria</em></span></span> spp<em>.</em> The results showed that 61% of samples met the Moroccan hygiene standards for vegetable paste spreads, with contamination levels of 4.21, 2.94, 2.38, 1.87, and 1.50 log cfu/g for TVC, YM, TC, FC, and <em>E. coli</em>, respectively. <em>S. aureus</em> was detected in 6.82% of <em>Amlou</em> samples, while <em>Salmonella</em> and <em>Listeria</em> spp. were not detected in any of the analyzed samples. On the other hand, the effects of water activity (a_w<span>) (0.44, 0.50, 0.53), temperature (23, 30 °C), and pH (5.5, 6.5) on the kinetics parameters, inactivation rate (IR, log cfu/g/d), and shoulder period (SP, d) of </span><em>E. coli</em> ATCC 25922, were investigated. The survival curves generated under different conditions were fitted using the Baranyi model. Secondary modeling for the combined effects of a_w, temperature, and pH on the survival parameters was carried out using a polynomial equation. Finally, the goodness of fit was assessed for the survival kinetics of <em>E. coli</em>. Root mean square error (RMSE) and standard error of prediction (%SEP) obtained were 0.20 and 10.22% for IR and 0.24 and 40.01% for SP. These models can provide an estimate of <em>E. coli</em> inactivation in <em>Amlou</em>. Further studies should consider other factors such as argan oil concentration and amount of protein before being applied to ensure food safety for <em>E. coli</em> control in <em>Amlou</em>.</p></div>","PeriodicalId":48593,"journal":{"name":"Microbial Risk Analysis","volume":"21 ","pages":"Article 100216"},"PeriodicalIF":2.8,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43785954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using thermodynamic equilibrium models to predict the effect of antiviral agents on infectivity: Theoretical application to SARS-CoV-2 and other viruses.","authors":"Paul Gale","doi":"10.1016/j.mran.2021.100198","DOIUrl":"10.1016/j.mran.2021.100198","url":null,"abstract":"&lt;div&gt;&lt;p&gt;Thermodynamic equilibrium models predict the infectivity of novel and emerging viruses using molecular data including the binding affinity of the virus to the host cell (as represented by the association constant K&lt;sub&gt;a_virus_T&lt;/sub&gt;) and the probability, p&lt;sub&gt;virogenesis&lt;/sub&gt;, of the virus replicating after entry to the cell. Here those models are adapted based on the principles of ligand binding to macromolecules to assess the effect on virus infectivity of inhibitor molecules which target specific proteins of the virus. Three types of inhibitor are considered using the thermodynamic equilibrium model for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of the human lung with parameters for the strength and nature of the interaction between the target virus protein and the inhibitor molecule. The first is competitive inhibition of the SARS-CoV-2 spike glycoprotein (SGP) trimer binding to its human angiotensin converting enzyme 2 (ACE2) receptor by unfractionated heparin (UFH). Using a novel approach presented here, a value of K&lt;sub&gt;a_virus_T&lt;/sub&gt; = 3.53 × 10&lt;sup&gt;17&lt;/sup&gt; M&lt;sup&gt;−1&lt;/sup&gt; is calculated for SARS-CoV-2 from the IC&lt;sub&gt;50&lt;/sub&gt; for inhibition by UFH of SARS-CoV-2 plaque formation in cell culture together with the dissociation constant K&lt;sub&gt;VI&lt;/sub&gt; of 0.73 × 10&lt;sup&gt;−10&lt;/sup&gt; M reported for heparin binding to SARS-CoV-2 SGP trimer. Such a high K&lt;sub&gt;a_virus_T&lt;/sub&gt; limits the effectiveness of competitive inhibitors such as UFH. The second is the attachment of a nanoparticle such as a zinc oxide tetrapod (ZnOT) to the virus shell as for herpes simplex virus (HSV). The increase in molecular weight through ZnOT attachment is predicted to decrease K&lt;sub&gt;a_virus_T&lt;/sub&gt; by orders of magnitude by making the entropy change (ΔS&lt;sub&gt;a_immob&lt;/sub&gt;) on immobilisation of the ZnOT:virus complex on cell binding more negative than for the virus alone. According to the model, ZnOT acts synergistically with UFH at the IC&lt;sub&gt;50&lt;/sub&gt; of 33 μg/cm&lt;sup&gt;3&lt;/sup&gt; which together decrease viral infectivity by 61,000-fold compared to the two-fold and three-fold decreases predicted for UFH alone at the IC&lt;sub&gt;50&lt;/sub&gt; and for ZnOT alone respectively. According to the model here, UFH alone at its peak deliverable dose to the lung of 1,000 μg/cm&lt;sup&gt;3&lt;/sup&gt; only decreases infectivity by 31-fold. Practicable approaches to target and decrease ΔS&lt;sub&gt;a_immob&lt;/sub&gt; for respiratory viruses should therefore be considered. The combination of decreasing ΔS&lt;sub&gt;a_immob&lt;/sub&gt; together with blocking the interaction of virus surface protein with its host cell receptor may achieve synergistic effects for faecal-oral viruses and HSV. The third is reversible noncompetitive inhibition of the viral main protease (M&lt;sup&gt;pro&lt;/sup&gt;) for which the decrease in p&lt;sub&gt;virogenesis&lt;/sub&gt; is assumed to be proportional to the decrease in enzyme activity as predicted by enzyme kinetic equations for a given concentration of inhibitor which binds to M&lt;sup&gt;pro","PeriodicalId":48593,"journal":{"name":"Microbial Risk Analysis","volume":"21 ","pages":"Article 100198"},"PeriodicalIF":2.8,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8642839/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39721646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strain Wars: Competitive interactions between SARS-CoV-2 strains are explained by Gibbs energy of antigen-receptor binding","authors":"Marko Popovic ,&nbsp;Marta Popovic","doi":"10.1016/j.mran.2022.100202","DOIUrl":"10.1016/j.mran.2022.100202","url":null,"abstract":"<div><p>Since the beginning of the COVID-19 pandemic, SARS-CoV-2 has mutated several times into new strains, with an increased infectivity. Infectivity of SARS-CoV-2 strains depends on binding affinity of the virus to its host cell receptor. In this paper, we quantified the binding affinity using Gibbs energy of binding and analyzed the competition between SARS-CoV-2 strains as an interference phenomenon. Gibbs energies of binding were calculated for several SARS-SoV-2 strains, including Hu-1 (wild type), B.1.1.7 (alpha), B.1.351 (beta), P.1 (Gamma), B.1.36 and B.1.617 (Delta). The least negative Gibbs energy of binding is that of Hu-1 strain, -37.97 kJ/mol. On the other hand, the most negative Gibbs energy of binding is that of the Delta strain, -49.50 kJ/mol. We used the more negative Gibbs energy of binding to explain the increased infectivity of newer SARS-CoV-2 strains compared to the wild type. Gibbs energies of binding was found to decrease chronologically, with appearance of new strains. The ratio of Gibbs energies of binding of mutated strains and wild type was used to define a susceptibility coefficient, which is an indicator of viral interference, where a virus can prevent or partially inhibit infection with another virus.</p></div>","PeriodicalId":48593,"journal":{"name":"Microbial Risk Analysis","volume":"21 ","pages":"Article 100202"},"PeriodicalIF":2.8,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8816792/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39792280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing Campylobacter cross-contamination of Danish broiler flocks at slaughterhouses considering true flock prevalence estimates and ad-hoc sampling","authors":"Alessandro Foddai,&nbsp;Nao Takeuchi-Storm,&nbsp;Birgitte Borck Høg,&nbsp;Jette Sejer Kjeldgaard,&nbsp;Jens Kirk Andersen,&nbsp;Johanne Ellis-Iversen","doi":"10.1016/j.mran.2022.100214","DOIUrl":"10.1016/j.mran.2022.100214","url":null,"abstract":"<div><p><em>Campylobacter</em> cross-contamination of Danish broiler flocks at slaughterhouses was investigated using data from two national surveillance components and from ad-hoc sampling. The animal level (AL) and food safety (FS) components from 2018 were compared. The AL component contained results of PCR on pools of cloacal swabs from 3,012 flocks processed at two Danish slaughterhouses (S1-S2), while the FS component regarded culture testing of leg skins from 999/3,012 flocks. The monthly “apparent” (AP) and “true” flock prevalence (TP) were estimated. Agreement between components was measured in percentage and in weighted-Kappa values. The relationship between the occurrence of cross-contamination (flock positive only in the FS component = cross-contaminated or <em>CC</em>, vs. flock negative in both components or <em>NegBoth</em>), slaughterhouse and surveillance period (quarter: Q1 to Q4) was evaluated by a generalized linear mixed effects (GLM) model. Thereafter, a linear mixed effects (LME) model was used to investigate the relationship between the level of meat contamination of carcass positive flocks (<em>y</em> = log10 colony forming units per gram, cfu/g), slaughterhouse, surveillance period, and flock type (<em>CC</em> vs. positive in both components or <em>PosBoth</em>). For both models, the farm was the random effect. Finally, in autumn 2019, ad-hoc field investigations were carried out testing caecal and neck skin samples, from two consecutive flocks at S1 and S2. Whole genome sequencing (WGS) was performed on isolates, for multilocus sequence typing (MLST) and single nucleotide polymorphisms (SNP) analysis. The monthly TP was always higher for the FS than for the AL component. Agreement between the components was substantial, but 8.1–8.6% of the flocks were <em>CC</em>. Those had median cfu/g 21–28 times lower than that of <em>PosBoth</em> flocks. In the GLM model, the explanatory variables were both significant (P-value &lt;0.05). For example, the odds ratios (ORs) were 8.4 (95% CI: 4.0; 17.6) for Q3 vs. Q1, and 3.1 (1.8; 5.2) for S2 vs. S1. In the LME model, the flock type and the interaction between the other two variables, were significant. In the field study, a caecal positive flock was succeeded by an initially negative flock, in one out of five sampling sessions at S2. The cecal negative flock was positive in 58.3% of the neck skins with the isolate genetically similar to that from the caecal positive flock. Those results show that cross-contamination can be affected by surveillance periods and slaughterhouses, and it can contribute significantly to the TP of carcass positive flocks.</p></div>","PeriodicalId":48593,"journal":{"name":"Microbial Risk Analysis","volume":"21 ","pages":"Article 100214"},"PeriodicalIF":2.8,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352352222000147/pdfft?md5=0fa710d7808469aa52d76a46cee7a52f&pid=1-s2.0-S2352352222000147-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41369800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Risk-based control of Campylobacter spp. in broiler farms and slaughtered flocks to mitigate risk of human campylobacteriosis – A One Health approach","authors":"Alessandro Foddai,&nbsp;Maarten Nauta,&nbsp;Johanne Ellis-Iversen","doi":"10.1016/j.mran.2021.100190","DOIUrl":"10.1016/j.mran.2021.100190","url":null,"abstract":"<div><p>Effects of risk-based control of <em>Campylobacter</em> spp. in Danish broiler farms and flocks were simulated, to assess potential reductions of human risk of campylobacteriosis, associated to the consumption of poultry meat produced in Denmark. Two national data streams were used and represented: Flock status by testing cloacal swabs (CS, 2018–2019) and carcass status by testing leg skin samples (LS, 2019). In the CS surveillance component all flocks slaughtered at the two major Danish slaughterhouses were tested with a polymerase chain reaction (PCR), while in LS one third randomly selected flocks were tested by culture (results in colony forming units per gram, cfu/g). Each farm was identified by its Central Husbandry Register (CHR) number. Two risk farm classification strategies (I-II) were based on CS data from 2018. Farms were classified as: always negative (Neg-CHRs), low risk (LowR-CHRs) and high risk (HighR-CHRs) farms. In strategy I, HighR-CHRs had more than five positive flocks, while in strategy II; they had more than 27.8% of the slaughtered flocks positive. Those two cut-offs were the annual 3^rd quartiles across positive farms. Thereafter, a risk assessment model was used to estimate the annual relative risk (RR) of human campylobacteriosis in 2019, compared to that of 2013. Three hypothetical levels of cfu/g reductions (A, B and C) were simulated on the LS positive flocks (&gt; 10 cfu/g) slaughtered by HighR-CHRs and were pairwise combined with the two classification strategies, yielding six risk-mitigation scenarios (A I-II; B I-II; C I-II). In scenarios A I-II, zero cfu/g were simulated, while in scenarios B and C, the original cfu/g were divided by three and by two. For each scenario, RRs were compared to the RR of the original cfu/g (scenario O).</p><p>In 2018, if all flocks from HighR-CHRs had been negative, the annual CS flock prevalence would have reduced from 19.7% to 7.6% (strategy I) or 9.6% (strategy II). Whereas in 2019, it would have reduced from 17.1% to 7.8% or 11.6%. In both years, HighR-CHRs delivered a high percentage of the total annual positive flocks (61.4–54.4% under strategy I and 51.2–32.6% with strategy II). In 2019, if HighR-CHRs had delivered only LS negative flocks, the RR would have reduced from 0.94 (scenario “O”) to 0.51 (A-I). Other scenarios showed smaller RR reductions. Targeting high risk farms/flocks for intensive control could improve One Health-ness of national action plans against <em>Campylobacter</em> spp.</p></div>","PeriodicalId":48593,"journal":{"name":"Microbial Risk Analysis","volume":"21 ","pages":"Article 100190"},"PeriodicalIF":2.8,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352352221000323/pdfft?md5=f45b79214e0c01a8c408d9668ddced31&pid=1-s2.0-S2352352221000323-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46694915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An updated assessment of the effect of control options to reduce Campylobacter concentrations in broiler caeca on human health risk in the European Union","authors":"Maarten Nauta ,&nbsp;Declan Bolton ,&nbsp;Matteo Crotta ,&nbsp;Johanne Ellis-Iversen ,&nbsp;Thomas Alter ,&nbsp;Michaela Hempen ,&nbsp;Winy Messens ,&nbsp;Marianne Chemaly","doi":"10.1016/j.mran.2021.100197","DOIUrl":"10.1016/j.mran.2021.100197","url":null,"abstract":"<div><p>Quantitative microbiological risk assessment (QMRA) studies have suggested that control options to reduce the concentration of <em>Campylobacter</em> spp. in broiler chicken caeca may be highly effective at reducing the risk of human campylobacteriosis. These QMRA studies have been updated based on scientific evidence obtained in the past decade. The relationship between <em>Campylobacter</em> concentrations in the caeca and on broiler skins after industrial processing was modelled by means of linear regression and combined with a number of consumer phase models (CPM) and dose-response (DR) models. The reduction of caecal <em>Campylobacter</em> concentration as reported for selected feed additives and vaccines, was used to estimate the relative risk reduction expressed as the percentage decrease in human campylobacteriosis cases in the EU associated with consumption of broiler meat. The model outputs suggest that the effectiveness of these control options are less pronounced than previously indicated. For example, the median estimate for the relative risk reduction obtained through a 2 log₁₀ reduction in caecal concentrations was 39% (95% CI 9–73%), whereas previous estimates were between 76 and 98%. The main reason for this finding is that recent studies show lower values for the slope of the regression line; the impact of using newly published DR models and CPMs is smaller. Still, the uncertainty associated to the estimated effects is large, mainly due to uncertainty about the slope of the regression line. Additionally, data on the effectiveness of vaccination and the application of feed and water additives obtained under field conditions are scarce, but they are a prerequisite to assess the risk reduction that may be achieved by these control options when applied in practice.</p></div>","PeriodicalId":48593,"journal":{"name":"Microbial Risk Analysis","volume":"21 ","pages":"Article 100197"},"PeriodicalIF":2.8,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42471098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating the likelihood of ESBL-producing E. coli carriage in slaughter-aged pigs following bacterial introduction onto a farm: A multiscale risk assessment","authors":"Catherine McCarthy ,&nbsp;Alexis Viel ,&nbsp;Chris Gavin ,&nbsp;Pascal Sanders ,&nbsp;Robin R.L. Simons","doi":"10.1016/j.mran.2021.100185","DOIUrl":"10.1016/j.mran.2021.100185","url":null,"abstract":"<div><p>The transmission of antimicrobial resistance (AMR) between animals, their environment, food and humans is a complex issue. Previous pharmacokinetic-pharmacodynamic (PKPD) models indicate that extended-spectrum β-lactamase (ESBL) resistant bacterial populations may be self-sustaining through horizontal and vertical gene transfer, even in the absence of antimicrobial pressure. However, models focusing purely on the biochemical aspects fail to incorporate the complicated host population dynamics which occur within a farm environment. Models of disease transmission within commercial farm environments can provide further insight to the on-farm transmission dynamics of AMR between animals and their environment, as well as predict the effect of various on-farm interventions. Here, we present a risk assessment which predicts the likelihood that slaughter-aged pigs would carry resistant bacteria after a single introduction of ESBL <em>E. coli</em> on commercial pig farms. We incorporate outputs from a PKPD model which explores the complex host/gastrointestinal bacteria interplay after antimicrobial treatment; with an on-farm model of bacterial transmission. The risk assessment is designed to be adaptable for the simultaneous transmission of multiple bacteria and resistant strains. We predicted that after introduction onto a pig farm, ESBL <em>E. coli</em> bacteria are likely to persist on the farm for more than a year, leading to a high batch prevalence (39.4% slaughter pigs, 5th and 95th percentiles: 0.0–57.5) and high faecal shedding. A comparison of different farm management types suggested that all-in-all-out housing was a protective measure for both prevalence in slaughter-aged pigs and faecal shedding rates. We applied two main interventions at the farm level, an enhanced cleaning and disinfectant (C&amp;D) protocol and isolation of pigs in sick pens for the duration of their antibiotic treatment. Both interventions were able to reduce the number of pigs shedding more than 2 log₁₀ ESBL <em>E. coli</em> from 18.7% (5th and 95th percentiles: 5.9–30.4) in the baseline scenario, to 7.2% (5th and 95th percentiles: 0.0–21.5) when an enhanced C&amp;D protocol was applied, 0.1% (5th and 95th percentiles: 0.0–0.3) when sick pens were used and 0.1% (5th and 95th percentiles: 0.0–0.3) when a combination of enhanced C&amp;D plus sick pens was used. Both scenarios also reduced the prevalence in batches of pigs going to slaughter. This effect was largest when sick pens were used, where 75% of batches had 0% positive pigs. The results suggest that a single introductory event is sufficient to cause a substantial risk of carriage in slaughter-aged pigs. Further quantitative microbial risk assessments (QMRA) are needed to consider the onwards risk posed to later parts of the food chain.</p></div>","PeriodicalId":48593,"journal":{"name":"Microbial Risk Analysis","volume":"20 ","pages":"Article 100185"},"PeriodicalIF":2.8,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44195437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the risk of acute gastrointestinal illness (AGI) acquired through recreational exposure to combined sewer overflow-impacted waters in Philadelphia: A quantitative microbial risk assessment","authors":"Shannon M. McGinnis ,&nbsp;Tucker Burch ,&nbsp;Heather M. Murphy","doi":"10.1016/j.mran.2021.100189","DOIUrl":"10.1016/j.mran.2021.100189","url":null,"abstract":"<div><p>Combined sewer overflows (CSOs) are known contributors of human fecal pollution in urban waterways. Exposure to these waterways occurs during recreational activities, including swimming, wading, and fishing. This study used quantitative microbial risk assessment (QMRA) to estimate the risk of acute gastrointestinal illness (AGI) due to recreation during CSO-impacted (&lt; 24 h after a CSO) and non-impacted (&gt; 24 h after a CSO) conditions. Water samples (<em>n</em> = 69) were collected from two creeks and one river in Philadelphia from June–August 2017–2019. HF183 concentrations were measured to estimate concentrations of five reference pathogens: <em>Cryptosporidium, Giardia</em>, norovirus, <em>E. coli</em> O157:H7, and <em>Salmonella</em>. Observational data on the types and frequency of recreational exposures were also collected. Results found that recreating &lt; 24 h after a CSO increased AGI risk by 39–75%, compared to recreating &gt; 24 h after a CSO. However, estimated health risks were still high for some exposure scenarios that occurred &gt; 24 h after a CSO. Crudes estimates determined that recreational activities along known CSO-impacted sites may account for 1–8% of all cases of salmonellosis, cryptosporidiosis, and giardiasis in the city of Philadelphia. Findings support risk reduction strategies that aim to reduce the frequency of CSOs in urban settings and may help target risk mitigation strategies.</p></div>","PeriodicalId":48593,"journal":{"name":"Microbial Risk Analysis","volume":"20 ","pages":"Article 100189"},"PeriodicalIF":2.8,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352352221000311/pdfft?md5=7fade244a857501e203726d8aa843089&pid=1-s2.0-S2352352221000311-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46798762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of test timing and isolation length to reduce the risk of COVID-19 infection associated with airplane travel, as determined by infectious disease dynamics modeling","authors":"Masashi Kamo ,&nbsp;Michio Murakami ,&nbsp;Seiya Imoto","doi":"10.1016/j.mran.2021.100199","DOIUrl":"10.1016/j.mran.2021.100199","url":null,"abstract":"<div><p>Effective measures to reduce the risk of coronavirus disease 2019 (COVID-19) infection in overseas travelers are urgently needed. However, the effectiveness of current testing and isolation protocols is not yet fully understood. Here, we examined how the timing of testing and the number of tests conducted affect the spread of COVID-19 infection associated with airplane travel. We used two mathematical models of infectious disease dynamics to examine how different test protocols changed the density of infected individuals traveling by airplane and entering another country. We found that the timing of testing markedly affected the spread of COVID-19 infection. A single test conducted on the day before departure was the most effective at reducing the density of infected individuals travelling; this effectiveness decreased with increasing time before departure. After arrival, immediate testing was found to overlook individuals infected on the airplane. With respect to preventing infected individuals from entering the destination country, isolation with a single test on day 7 or 8 after arrival was comparable with isolation only for 11 or 14 days, respectively, depending on the model used, indicating that isolation length can be shortened with appropriately timed testing.</p></div>","PeriodicalId":48593,"journal":{"name":"Microbial Risk Analysis","volume":"20 ","pages":"Article 100199"},"PeriodicalIF":2.8,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8664726/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39739865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}