A. Thebault - Academia.edu (original) (raw)

Papers by A. Thebault

Organohalogen compounds, 2007

The aim of the French Dioxin and Incinerators Study was to evaluate the serum PCDDs, PCDFs and PC... more The aim of the French Dioxin and Incinerators Study was to evaluate the serum PCDDs, PCDFs and PCBs concentration distribution in 1030 randomly selected residents living in the vicinity of 8 municipal solid waste incinerators and its association with dioxin exposure, particularly with intake of local food produced under the incinerator's plume. The geometric mean of serum concentrations for the study population was 13.7 pg TEQ/g for PCDD/Fs lipids and 27.7 for the total TEQ. Globally, we did not observe any difference in geometric mean of serum dioxin levels between the residents living around incinerators and the residents living far from any known source of dioxins. Nevertheless, the analysis of the local consumers showed an increase of their serum dioxins levels with the consumption of local products from animal origin such as dairy products, eggs and more generally lipids. It is important to stress that this influence was observed for old incinerators, but not for the recent...

Temperature and relative humidity are major factors determining virus inactivation in the environ... more Temperature and relative humidity are major factors determining virus inactivation in the environment. This article reviews inactivation data of coronaviruses on surfaces and in liquids from published studies and develops secondary models to predict coronaviruses inactivation as a function of temperature and relative humidity. A total of 102 D-values (time to obtain a log10 reduction of virus infectivity), including values for SARS-CoV-2, were collected from 26 published studies. The values obtained from the different coronaviruses and studies were found to be generally consistent. Five different models were fitted to the global dataset of D-values. The most appropriate model considered temperature and relative humidity. A spreadsheet predicting the inactivation of coronaviruses and the associated uncertainty is presented and can be used to predict virus inactivation for untested temperatures, time points or new coronavirus strains.ImportanceThe prediction of the persistence of SARS...

Revue Scientifique et Technique de l'OIE

Scientific Supports to Policy (SSP). Position paper on consequence assessment – measuring the imp... more Scientific Supports to Policy (SSP). Position paper on consequence assessment – measuring the impact of pathogen exchange and disease interaction between wild and farmed aquatic animal populations

Veterinary Research

The management of infectious diseases in wildlife reservoirs is challenging and faces several lim... more The management of infectious diseases in wildlife reservoirs is challenging and faces several limitations. However, detailed knowledge of host–pathogen systems often reveal heterogeneity among the hosts’ contribution to transmission. Management strategies targeting specific classes of individuals and/or areas, having a particular role in transmission, could be more effective and more acceptable than population-wide interventions. In the wild population of Alpine ibex (Capra ibex—a protected species) of the Bargy massif (French Alps), females transmit brucellosis (Brucella melitensis) infection in ~90% of cases, and most transmissions occur in the central spatial units (“core area”). Therefore, we expanded an individual-based model, developed in a previous study, to test whether strategies targeting females or the core area, or both, would be more effective. We simulated the relative efficacy of realistic strategies for the studied population, combining test-and-remove (euthanasia of...

Applied and Environmental Microbiology

The prediction of the persistence of SARS-CoV-2 on fomites is essential in investigating the impo... more The prediction of the persistence of SARS-CoV-2 on fomites is essential in investigating the importance of contact transmission. This study collects available information on inactivation kinetics of coronaviruses in both solid and liquid fomites and creates a mathematical model for the impact of temperature and relative humidity on virus persistence. The predictions of the model can support more robust decision‐making and could be useful in various public health contexts. A calculator for the natural clearance of SARS-CoV-2 depending on temperature and relative humidity could be a valuable operational tool for public authorities.

Preventive Veterinary Medicine

INRAE Productions Animales

La lutte contre la propagation des maladies infectieuses et les conséquences de celles-ci de mani... more La lutte contre la propagation des maladies infectieuses et les conséquences de celles-ci de manière préventive est particulièrement importante en santé des espèces aquacoles, du fait des difficultés d’éradication des maladies une fois qu’elles sont introduites, notamment en milieu marin. Par conséquent, la modélisation en tant qu’outil prédictif est particulièrement justifiée. Une revue bibliographique a été menée dans le cadre du projet européen DIPNET en vue de dresser l’inventaire des modèles utilisés dans le domaine de la santé des espèces aquacoles. L’appréciation quantitative des risques commence à se développer pour certaines maladies des salmonidés d’Europe du nord, visant à garantir les transferts, aider les programmes, surveiller et prévenir l’apparition de maladies émergentes. Les modèles dynamiques de maladies commencent à être utilisés pour la gestion du risque, pour les salmonidés et pour les coquillages (USA) mais sont, suivant leur complexité, coûteux en données et ...

Parasite

In France, the consumption of cattle and sheep meat appears to be a risk factor for infection of ... more In France, the consumption of cattle and sheep meat appears to be a risk factor for infection of pregnant women with Toxoplasma gondii. Several nation-wide surveys in France have investigated the prevalence of T. gondii in sheep and pig meat, but little is known at present about the prevalence of the parasite in beef. The main objective of the present cross-sectional survey was to estimate the seroprevalence of T. gondii infection in beef consumed in France. A secondary objective was to attempt to isolate T. gondii from cattle tissues and to study the geographical and age variations of this seroprevalence. The overall estimate of seroprevalence of T. gondii in bovine carcasses (n = 2912), for a threshold of 1:6 was 17.38%. A strong age effect was observed (p 8 months). Seroprevalence estimates given by area of birth and area of slaughtering for adults showed that the areas with the highest seroprevalence were not the same between these two variables. Only two strains, corresponding ...

Frontiers in Microbiology

Source Attribution of Foodborne Diseases and concentration) of a given pathogen in each source, a... more Source Attribution of Foodborne Diseases and concentration) of a given pathogen in each source, and then go upwards in the transmission chain incorporating factors related to human exposure to these sources and dose-response relationships. Other approaches are intervention studies, including 'natural experiments,' and expert elicitations. A number of methodological challenges concerning all these approaches are discussed. In absence of an universally agreed upon 'gold' standard, i.e., a single method that satisfies all situations and needs for all pathogens, combining different approaches or applying them in a comparative fashion seems to be a promising way forward.

Toxins

Paralytic shellfish poisoning (PSP) is caused by a group of marine toxins with saxitoxin (STX) as... more Paralytic shellfish poisoning (PSP) is caused by a group of marine toxins with saxitoxin (STX) as the reference compound. Symptoms in humans after consumption of contaminated shellfish vary from slight neurological and gastrointestinal effects to fatal respiratory paralysis. A systematic review was conducted to identify reported cases of human poisoning associated with the ingestion of shellfish contaminated with paralytic shellfish toxins (PSTs). Raw data were collected from 143 exposed individuals (113 with symptoms, 30 without symptoms) from 13 studies. Exposure estimates were based on mouse bioassays except in one study. A significant relationship between exposure to PSTs and severity of symptoms was established by ordinal modelling. The critical minimal dose with a probability higher than 10% of showing symptoms is 0.37 µg STX eq./kg b.w. This means that 10% of the individuals exposed to this dose would have symptoms (without considering the severity of the symptoms). This dose...

Microbial Risk Analysis

In order to design effective public health strategies, and, in particular, effective food safety ... more In order to design effective public health strategies, and, in particular, effective food safety interventions to reduce the burden of foodborne disease, the most important sources of enteric illnesses should be identified. Both case-control and cohort observational studies have for long been powerful approaches among epidemiologists to investigate the association of exposure and illness. In the literature, there are numerous case-control and cohort studies reporting results on risk factors and routes of transmission of sporadic foodborne infections. The objective of this article is to describe, in depth, the strategies implemented for systematic review and meta-analysis of the associations between multiple risk factors and eleven food and waterborne diseases, namely, non-typhoidal salmonellosis, campylobacteriosis, Shiga-toxin E. coli infection, listeriosis, yersiniosis, toxoplasmosis, norovirus infection, hepatitis A, hepatitis E, cryptosporidiosis and giardiasis. First, this article describes the procedures of systematic searches in five bibliographic engines, screening of relevance and assessment of methodological quality according to pre-set criteria. It proceeds with the explanation of a broad data categorisation scheme established to hierarchically group the risk factors into travel, host-specific factors and pathways of exposure (i.e., person-to-person, animal, environment and food routes), with views to harmonising and supporting the integration of outcomes from studies investigating a variety of potential determinants of disease. Next, the article describes the four meta-analysis models that were devised in order to calculate: (i) overall oddsratios of acquiring the disease due to a specific risk factor by geographical region; (ii) overall odds-ratios of acquiring the disease from the different risk factors; (iii) overall risks of disease from consumption of ready-toeat and barbecued foods; and (iv) overall effects of food handling (i.e., consuming food in raw, undercooked or unwashed state) and food preparation setting (i.e., eating food prepared outside the home) on risk of disease. The procedures for sensitivity analysis and removal of any influential and potentially-biased odds-ratio; and two methods for publication bias assessment are outlined. Finally, details are given on deviations from the standard risk categorisation scheme for specific foodborne hazards.

Frontiers in microbiology, 2018