Browsing by Author "Sanaa, Moez"
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- A critical review of risk assessment models for listeria monocytogenes in dairy productsPublication . Gonzales-Barron, Ursula; Cadavez, Vasco; Guillier, Laurent; Sanaa, MoezA review of the published quantitative risk assessment (QRA) models of L. monocytogenes in dairy products was undertaken in order to identify and appraise the relative effectiveness of control measures and intervention strategies implemented at primary production, processing, retail, and consumer practices. A systematic literature search retrieved 18 QRA models, most of them (9) investigated raw and pasteurized milk cheeses, with the majority covering long supply chains (4 farm-to-table and 3 processing-to-table scopes). On-farm contamination sources, either from shedding animals or from the broad environment, have been demonstrated by different QRA models to impact the risk of listeriosis, in particular for raw milk cheeses. Through scenarios and sensitivity analysis, QRA models demonstrated the importance of the modeled growth rate and lag phase duration and showed that the risk contribution of consumers’ practices is greater than in retail conditions. Storage temperature was proven to be more determinant of the final risk than storage time. Despite the pathogen’s known ability to reside in damp spots or niches, re-contamination and/or cross-contamination were modeled in only two QRA studies. Future QRA models in dairy products should entail the full farm-to-table scope, should represent cross-contamination and the use of novel technologies, and should estimate L. monocytogenes growth more accurately by means of better-informed kinetic parameters and realistic time–temperature trajectories.
- A Critical Review of Risk Assessment Models for Listeria monocytogenes in Meat and Meat ProductsPublication . Gonzales-Barron, Ursula; Cadavez, Vasco; Mota, Juliana de Oliveira; Guillier, Laurent; Sanaa, MoezA review of the published quantitative risk assessment (QRA) models of L. monocytogenes in meat and meat products was performed, with the objective of appraising the intervention strategies deemed suitable for implementation along the food chain as well as their relative effectiveness. A systematic review retrieved 23 QRA models; most of them (87%) focused on ready-to-eat meat products and the majority (78%) also covered short supply chains (end processing/retail to consumption, or consumption only). The processing-to-table scope was the choice of models for processed meats such as chorizo, bulk-cooked meat, fermented sausage and dry-cured pork, in which the effects of processing were simulated. Sensitivity analysis demonstrated the importance of obtaining accurate estimates for lag time, growth rate and maximum microbial density, in particular when affected by growth inhibitors and lactic acid bacteria. In the case of deli meats, QRA models showed that delicatessen meats sliced at retail were associated with a higher risk of listeriosis than manufacture pre-packed deli meats. Many models converged on the fact that (1) controlling cold storage temperature led to greater reductions in the final risk than decreasing the time to consumption and, furthermore, that (2) lower numbers and less prevalence of L. monocytogenes at the end of processing were far more effective than keeping low temperatures and/or short times during retail and/or home storage. Therefore, future listeriosis QRA models for meat products should encompass a processing module in order to assess the intervention strategies that lead to lower numbers and prevalence, such as the use of bio-preservation and novel technologies. Future models should be built upon accurate microbial kinetic parameters, and should realistically represent cross-contamination events along the food chain.
- A Critical Review of Risk Assessment Models for Listeria monocytogenes in ProducePublication . Gonzales-Barron, Ursula; Cadavez, Vasco; Mota, Juliana de Oliveira; Guillier, Laurent; Sanaa, MoezA review of quantitative risk assessment (QRA) models of Listeria monocytogenes in produce was carried out, with the objective of appraising and contrasting the effectiveness of the control strategies placed along the food chains. Despite nine of the thirteen QRA models recovered being focused on fresh or RTE leafy greens, none of them represented important factors or sources of contamination in the primary production, such as the type of cultivation, water, fertilisers or irrigation method/practices. Cross-contamination at processing and during consumer's handling was modelled using transfer rates, which were shown to moderately drive the final risk of listeriosis, therefore highlighting the importance of accurately representing the transfer coefficient parameters. Many QRA models coincided in the fact that temperature fluctuations at retail or temperature abuse at home were key factors contributing to increasing the risk of listeriosis. In addition to a primary module that could help assess current on-farm practices and potential control measures, future QRA models for minimally processed produce should also contain a refined sanitisation module able to estimate the effectiveness of various sanitisers as a function of type, concentration and exposure time. Finally, L. monocytogenes growth in the products down the supply chain should be estimated by using realistic time-temperature trajectories, and validated microbial kinetic parameters, both of them currently available in the literature.
- A Critical Review of Risk Assessment Models for Listeria monocytogenes in SeafoodPublication . Gonzales-Barron, Ursula; Cadavez, Vasco; Mota, Juliana de Oliveira; Guillier, Laurent; Sanaa, MoezInvasive listeriosis, due to its severe nature in susceptible populations, has been the focus of many quantitative risk assessment (QRA) models aiming to provide a valuable guide in future risk management efforts. A review of the published QRA models of Listeria monocytogenes in seafood was performed, with the objective of appraising the effectiveness of the control strategies at different points along the food chain. It is worth noting, however, that the outcomes of a QRA model are context-specific, and influenced by the country and target population, the assumptions that are employed, and the model architecture itself. Studies containing QRA models were retrieved through a literature search using properly connected keywords on Scopus and PubMed®. All 13 QRA models that were recovered were of short scope, covering, at most, the period from the end of processing to consumption; the majority (85%) focused on smoked or gravad fish. Since the modelled pathways commenced with the packaged product, none of the QRA models addressed cross-contamination events. Many models agreed that keeping the product’s temperature at 4.0–4.5 °C leads to greater reductions in the final risk of listeriosis than reducing the shelf life by one week and that the effectiveness of both measures can be surpassed by reducing the initial occurrence of L. monocytogenes in the product (at the end of processing). It is, therefore, necessary that future QRA models for RTE seafood contain a processing module that can provide insight into intervention strategies that can retard L. monocytogenes’ growth, such as the use of bacteriocins, ad hoc starter cultures and/or organic acids, and other strategies seeking to reduce cross-contamination at the facilities, such as stringent controls for sanitation procedures. Since risk estimates were shown to be moderately driven by growth kinetic parameters, namely, the exponential growth rate, the minimum temperature for growth, and the maximum population density, further work is needed to reduce uncertainties.
- Editorial note to the special issue “Risk factors for sporadic foodborne diseases by meta-analysis of observational studies”Publication . Gonzales-Barron, Ursula; Cadavez, Vasco; Thebault, Anne; Kooh, Pauline; Sanaa, MoezEpidemiological studies are valuable tools for investigating the origin of outbreaks and also sporadic cases in order to better understand the circumstances of foodborne disease occurrence. It is common to report ad hoc analyses of compiled data of food-borne disease outbreaks, however, such analyses including sporadic cases remain relatively rare. In the literature, several case-control and cohort studies have been published that investigate associations of sporadic foodborne diseases with diverse exposure pathways, foods, food handling practices and health pre-conditions in different populations. This special issue compiles several epidemiological studies of spo- radic cases of leading foodborne infectious diseases, and summarises the measurements of associations (odds ratios) of risk factors with the occurrence of sporadic cases. These odds ratio estimates in combination with the frequency of exposure to risk factors will allow the contribu- tions of the different risk factors to be assessed based on calculations of attributable fractions. Source attribution has been traditionally accom- plished by different methods such as epidemiological studies, microbial subtyping models, comparative exposure assessments and expert’s knowledge elicitation. Yet, there has been very few publications using meta-analysis to better understand risk factor identification and help prioritize and quantify interventions measures to reduce the impact of foodborne diseases.
- Hierarquização dos factores de risco associados à salmonelose por meta-análise de estudos caso-controloPublication . Rodrigues, Vânia; Cadavez, Vasco; Gonzales-Barron, Ursula; Kooh, Pauline; Sanaa, Moez; Rodrigues, VâniaOs estudos caso-controlo são uma metodologia de investigação em epidemiologia que permitem analisar, de forma retrospectiva, a exposição a factores de risco das doenças entéricas. O objectivo deste trabalho foi sintetizar a associação entre as infecções esporádicas por Salmonella spp. e os factores de risco, através da combinação dos resultados de estudos casocontrolo. Para uniformizar as categorias de exposição, desenvolvemos uma classificação dos eventuais factores de risco, com as seguintes categorias: viagem, especificidades do hospedeiro, transmissão de pessoa a pessoa, contacto com animais, contaminação pelo ambiente e consumo de alimentos. A pesquisa da literatura relevante foi realizada através dos portais da Science Direct, Pubmed, Scielo, 151 Web of Science e Scopus. Em cada estudo caso-controlo, foi recolhida a medida de associação oddsratio (ORs) da doença com a exposição. Os estudos seleccionados foram classificados quanto ao seu potencial de enviesamento, resultante de deficiências do desenho experimental, da selecção da população e dos métodos utilizados na análise dos dados. Foram também extraídas outras características consideradas importantes, tais como: a população, o desenho experimental, a análise estatística dos dados e o(s) factor(es) de risco. Posteriormente, os ORs globais, para cada factor de risco e das rotas de transmissão, foram estimados por modelos de meta-análise com o software R, e hierarquizados.
- Meta-análise do contato com animais como rota de transmissão de toxoplasmose esporádicaPublication . Rodrigues, Vânia; Cadavez, Vasco; Kooh, Pauline; Sanaa, Moez; Gonzales-Barron, Ursula; Rodrigues, VâniaA toxoplasmose é uma infeção causada pelo parasita Toxoplasma gondii, cuja transmissão ocorre por ingestão de alimentos contaminados, contato com animais (zoonose) e de mãe para filho (congénita). O objetivo deste estudo foi sintetizar a associação entre a infeção esporádica por T. gondii e o contato com animais, através da combinação dos resultados de estudos de caso-controlo relevantes, usando a meta-análise para produzir uma estimativa mais precisa da associação global entre o fator de risco e a doença.
- Meta-análise do contato com animais e do consumo de carne como fontes de salmonelose esporádicaPublication . Gonçalves-Tenório, Andiara; Cadavez, Vasco; Rodrigues, Vânia; Kooh, Pauline; Sanaa, Moez; Gonzales-Barron, Ursula; Rodrigues, VâniaAs doenças gastrointestinais representam um importante problema de saúde pública em todo mundo, desta forma a identificação da origem de transmissão é de grande importância para a avaliação e atribuição de risco. Os estudos epidemiológicos de casocontrolo são usados para identificar os fatores de risco associados à transmissão das doenças. A salmonelose, doença causada por vários serotipos de Salmonella spp., pode ser transmitida ao homem de diversas formas. De uma forma geral, os casos esporádicos de salmonelose não partilham o mesmo fator de risco ou rota de contaminação, de modo que os estudos que medem a relação de probabilidades (“odds ratio”, OR) de qualquer fonte de transmissão podem ocultar os riscos reais tornando-os mais difíceis de detetar (Fullerton et al., 2012). Por exemplo, o frango assado é uma importante fonte de contaminação por Salmonella spp., todavia a maioria das porções de frango não estão contaminadas, de modo que a probabilidade de uma pessoa adquirir salmonelose pelo consumo de frango assado é apenas um pouco superior à das pessoas que não consomem frango assado (controlo).
- Meta-análise do contato com animais e do consumo de carne como fontes de salmonelose esporádicaPublication . Gonçalves-Tenório, Andiara; Cadavez, Vasco; Rodrigues, Vânia; Kooh, Pauline; Sanaa, Moez; Gonzales-Barron, Ursula; Rodrigues, VâniaAs doenças gastrointestinais representam um importante problema de saúde pública em todo mundo, desta forma a identificação da origem de transmissão é de grande importância para a avaliação e atribuição de risco. Os estudos epidemiológicos de casocontrolo são usados para identificar os fatores de risco associados à transmissão das doenças. A salmonelose, doença causada por vários serotipos de Salmonella spp., pode ser transmitida ao homem de diversas formas. De uma forma geral, os casos esporádicos de salmonelose não partilham o mesmo fator de risco ou rota de contaminação, de modo que os estudos que medem a relação de probabilidades (“odds ratio”, OR) de qualquer fonte de transmissão podem ocultar os riscos reais tornando-os mais difíceis de detetar (Fullerton et al., 2012). Por exemplo, o frango assado é uma importante fonte de contaminação por Salmonella spp., todavia a maioria das porções de frango não estão contaminadas, de modo que a probabilidade de uma pessoa adquirir salmonelose pelo consumo de frango assado é apenas um pouco superior à das pessoas que não consomem frango assado (controlo).
- Pathogens-in-Foods database: A web application for assessing the occurrence data of microbiological hazards in foods marketed in EuropePublication . Faria, Ana Sofia; Winter, Maiara; Thebault, Anne; Guillier, Laurent; Sanaa, Moez; Kooh, Pauline; Cadavez, Vasco; Gonzales-Barron, UrsulaPathogens-in-Foods (PIF) is a dynamic database constructed using systematic literature searches of occurrence data (prevalence and enumeration) of important pathogenic agents (Bacillus cereus, Campylobacter spp., Clostridium perfringens, Listeria monocytogenes, Salmonella spp., Shiga toxin-producing Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica, Cryptosporidium spp., Giardia spp., Toxoplasma gondii, Hepatitis A virus, Hepatitis E virus and Norovirus) in foods randomly surveyed across Europe. After filtering the primary studies, these were screened for relevance and methodological quality, and the data were extracted into the PIF database following a systematic categorisation of microbiological methods, food types and outcomes. The database is freely accessible through a web application that facilitates data retrieval according to several relevant variables. The PIF spans data published from 2000 onwards and is intended for use by researchers and food authorities after meta-analysis, in microbiological risk assessment.