Maisons-Alfort, France
Maisons-Alfort, France

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Azzag N.,National Veterinary School of Algiers | Haddad N.,National Veterinary School of Alfort | Durand B.,Laboratoire Of Sante Animale | Petit E.,National Veterinary School of Alfort | And 3 more authors.
PLoS ONE | Year: 2012

Whole blood samples from 211 stray cats from Algiers, Algeria, were cultured to detect the presence of Bartonella species and to evaluate the genetic diversity of B. henselae strains by multiple locus VNTR analysis (MLVA). Bartonella henselae was the only species isolated from 36 (17%) of 211 cats. B. henselae genotype I was the predominant genotype (64%). MLVA typing of 259 strains from 30 bacteremic cats revealed 52 different profiles as compared to only 3 profiles using MLST. Of these 52 profiles, 48 (92.3%) were identified for the first time. One-third of the cats harbored one MLVA profile only. As there was a correlation between the age of cats and the number of MLVA profiles, we hypothesized that the single profile in these cats was the profile of the initial infecting strain. Two-third of the cats harbored 2 to 6 MLVA profiles simultaneously. The similarity of MLVA profiles obtained from the same cat, neighbor-joining clustering and structure-neighbor clustering indicate that such a diversity likely results from two different mechanisms occurring either independently or simultaneously: independent infections and genetic drift from a primary strain. © 2012 Azzag et al.


Bouquet J.,Laboratoire Of Sante Animale | Bouquet J.,French National Institute for Agricultural Research | Bouquet J.,National Veterinary School of Alfort | Cherel P.,France Hybrides | And 3 more authors.
Infection, Genetics and Evolution | Year: 2012

Hepatitis E virus (HEV) is present in different species and ecological niches. It has been divided into 4 major mammalian genotypes. In this study, 3 new full-length genomes of swine HEV were sequenced and the results did not reveal any particular host determinant in comparison with human isolates belonging to the same genotype. Nucleotide composition and codon usage bias were determined to characterize HEV host restriction and genome evolution. Peculiar nucleotide bias was observed for A and C nucleotides in all HEV genotypes. Apart from the ORF1 hypervariable region and the ORF2/3 overlapping region, no nucleotide bias was observed between the 3 codon positions. CpG dinucleotides were also shown to be under-represented in HEV as in most RNA viruses. The effective number of codon used in HEV genome was high, indicating a lack of codon bias. Correspondence analysis of the relative synonymous codon usage was performed and demonstrated that evolution of HEV is not driven by geographical or host factors, but is representative of HEV phylogeny. These results confirm that HEV genome evolution is mainly based on mutational pressure. Natural selection, for instance involving fine-tuning translation kinetics and escape from the host immune system, may also play a role in shaping the HEV genome, particularly in the ORF1 hypervariable region and the ORF2/3 overlapping region. These regions might be involved in host restriction. Finally this study revealed the need to re-evaluate the possible subtyping classification. © 2012 Elsevier B.V.


Barnaud E.,Laboratoire Of Sante Animale | Barnaud E.,French National Institute for Agricultural Research | Barnaud E.,National Veterinary School of Alfort | Rogee S.,Laboratoire Of Sante Animale | And 7 more authors.
Applied and Environmental Microbiology | Year: 2012

Hepatitis E virus (HEV) infection of zoonotic origin is an emerging concern in industrialized countries. In the past few years,several cases of zoonotic hepatitis E have been identified and the consumption of food products derived from pork liver have been associated with clusters of human cases. More specifically, raw or undercooked pork products have been incriminated. Few data on the effect of heating on HEV inactivation in food products are available. In the present study,the various times and temperatures that are used during industrial processing of pork products were applied to experimentally contaminated food preparations.After treatment, the presence of residual infectious virus particles was investigated using real-time reverse transcription-PCR and an in vivo experimental model in pigs. Results show that heating the food to an internal temperature of 71°C for 20 min is necessary to completely inactivate HEV. These results are very important for determining processing methods to ensure food safety in regard to food-borne hepatitis E. © 2012, American Society for Microbiology.


Hogerwerf L.,University Utrecht | Courcoul A.,French National Institute for Agricultural Research | Courcoul A.,National School of Engineering in Agricultural and Food Industries | Courcoul A.,Laboratoire Of Sante Animale | And 5 more authors.
Veterinary Research | Year: 2013

Between 2007 and 2009, the largest human Q fever epidemic ever described occurred in the Netherlands. The source was traced back to dairy goat farms, where abortion storms had been observed since 2005. Since one putative cause of these abortion storms is the intensive husbandry systems in which the goats are kept, the objective of this study was to assess whether these could be explained by herd size, reproductive pattern and other demographic aspects of Dutch dairy goat herds alone. We adapted an existing, fully parameterized simulation model for Q fever transmission in French dairy cattle herds to represent the demographics typical for Dutch dairy goat herds. The original model represents the infection dynamics in a herd of 50 dairy cows after introduction of a single infected animal; the adapted model has 770 dairy goats. For a full comparison, herds of 770 cows and 50 goats were also modeled. The effects of herd size and goat versus cattle demographics on the probability of and time to extinction of the infection, environmental bacterial load and abortion rate were studied by simulation. The abortion storms could not be fully explained by demographics alone. Adequate data were lacking at the moment to attribute the difference to characteristics of the pathogen, host, within-herd environment, or a combination thereof. The probability of extinction was higher in goat herds than in cattle herds of the same size. The environmental contamination was highest within cattle herds, which may be taken into account when enlarging cattle farming systems. © 2013 Hogerwerf et al.; licensee BioMed Central Ltd.


Durand B.,Laboratoire Of Sante Animale | Lecollinet S.,Laboratoire Of Sante Animale | Beck C.,Laboratoire Of Sante Animale | Martinez-Lopez B.,Complutense University of Madrid | And 2 more authors.
PLoS ONE | Year: 2013

Live animal trade is considered a major mode of introduction of viruses from enzootic foci into disease-free areas. Due to societal and behavioural changes, some wild animal species may nowadays be considered as pet species. The species diversity of animals involved in international trade is thus increasing. This could benefit pathogens that have a broad host range such as arboviruses. The objective of this study was to analyze the risk posed by live animal imports for the introduction, in the European Union (EU), of four arboviruses that affect human and horses: Eastern and Western equine encephalomyelitis, Venezuelan equine encephalitis and Japanese encephalitis. Importation data for a five-years period (2005-2009, extracted from the EU TRACES database), environmental data (used as a proxy for the presence of vectors) and horses and human population density data (impacting the occurrence of clinical cases) were combined to derive spatially explicit risk indicators for virus introduction and for the potential consequences of such introductions. Results showed the existence of hotspots where the introduction risk was the highest in Belgium, in the Netherlands and in the north of Italy. This risk was higher for Eastern equine encephalomyelitis (EEE) than for the three other diseases. It was mainly attributed to exotic pet species such as rodents, reptiles or cage birds, imported in small-sized containments from a wide variety of geographic origins. The increasing species and origin diversity of these animals may have in the future a strong impact on the risk of introduction of arboviruses in the EU. © 2013 Durand et al.


Chevalier V.,CIRAD - Agricultural Research for Development | Rakotondrafara T.,British Petroleum | Jourdan M.,CIRAD - Agricultural Research for Development | Heraud J.M.,Institute Pasteur Of Madagascar | And 5 more authors.
PLoS Neglected Tropical Diseases | Year: 2011

Rift Valley fever is an acute, zoonotic viral disease of domestic ruminants, caused by a phlebovirus (Bunyaviridae family). A large outbreak occurred in Madagascar in 2008-2009. The goal of the present study was to evaluate the point prevalence of antibodies against Rift Valley Fever Virus (RVFV) in cattle in the Anjozorobe district, located in the wet and temperate highland region of Madagascar and yet heavily affected by the disease, and analyse environmental and trade factors potentially linked to RVFV transmission. A serological study was performed in 2009 in 894 bovines. For each bovine, the following variables were recorded: age, location of the night pen, minimum distance from the pen to the nearest water point and the forest, nearest water point type, and herd replacement practices. The serological data were analyzed using a generalized linear mixed model. The overall anti-RVFV IgG seroprevalence rate was 28% [CI95% 25-31]. Age was statistically linked to prevalence (p = 10 -4), being consistent with a recurrent RVFV circulation. Distance from the night pen to the nearest water point was a protective factor (p = 5.10 -3), which would be compatible with a substantial part of the virus transmission being carried out by nocturnal mosquito vectors. However, water point type did not influence the risk of infection: several mosquito species are probably involved. Cattle belonging to owners who purchase animals to renew the herd were significantly more likely to have seroconverted than others (p = 0.04): cattle trade may contribute to the introduction of the virus in this area. The minimum distance of the night pen to the forest was not linked to the prevalence. This is the first evidence of a recurrent transmission of RVFV in such an ecosystem that associates a wet, temperate climate, high altitude, paddy fields, and vicinity to a dense rain forest. Persistence mechanisms need to be further investigated. © 2011 Chevalier et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Bouquet J.,Laboratoire Of Sante Animale | Tesse S.,Hopital des Armees Val de Grace | Lunazzi A.,Laboratoire Of Sante Animale | Eloit M.,National Veterinary School of Alfort | And 3 more authors.
Emerging Infectious Diseases | Year: 2011

Frequent zoonotic transmission of hepatitis E virus (HEV) has been suspected, but data supporting the animal origin of autochthonous cases are still sparse. We assessed the genetic identity of HEV strains found in humans and swine during an 18-month period in France. HEV sequences identified in patients with autochthonous hepatitis E infection (n = 106) were compared with sequences amplified from swine livers collected in slaughterhouses (n = 43). Phylogenetic analysis showed the same proportions of subtypes 3f (73.8%), 3c (13.4%), and 3e (4.7%) in human and swine populations. Furthermore, similarity of >99% was found between HEV sequences of human and swine origins. These results indicate that consumption of some pork products, such as raw liver, is a major source of exposure for autochthonous HEV infection.


Vergne T.,Laboratoire Of Sante Animale | Vergne T.,CIRAD - Agricultural Research for Development | Calavas D.,ANSES Lyon | Cazeau G.,ANSES Lyon | And 3 more authors.
Preventive Veterinary Medicine | Year: 2012

Capture-recapture (CR) methods are used to study populations that are monitored with imperfect observation processes. They have recently been applied to the monitoring of animal diseases to evaluate the number of infected units that remain undetected by the surveillance system. This paper proposes three Bayesian models to estimate the total number of scrapie-infected holdings in France from CR count data obtained from the French classical scrapie surveillance programme. We fitted two zero-truncated Poisson (ZTP) models (with and without holding size as a covariate) and a zero-truncated negative binomial (ZTNB) model to the 2006 national surveillance count dataset. We detected a large amount of heterogeneity in the count data, making the use of the simple ZTP model inappropriate. However, including holding size as a covariate did not bring any significant improvement over the simple ZTP model. The ZTNB model proved to be the best model, giving an estimation of 535 (CI 95% 401-796) infected and detectable sheep holdings in 2006, although only 141 were effectively detected, resulting in a holding-level prevalence of 4.4‰ (CI 95% 3.2-6.3) and a sensitivity of holding-level surveillance of 26% (CI 95% 18-35). The main limitation of the present study was the small amount of data collected during the surveillance programme. It was therefore not possible to build complex models that would allow depicting more accurately the epidemiological and detection processes that generate the surveillance data. We discuss the perspectives of capture-recapture count models in the context of animal disease surveillance. © 2012 Elsevier B.V.


Chevalier V.,CIRAD - Agricultural Research for Development | Lecollinet S.,Laboratoire Of Sante Animale | Durand B.,Laboratoire Of Sante Animale
Vector-Borne and Zoonotic Diseases | Year: 2011

Current knowledge suggests that there is a low-level and recurrent circulation of West Nile virus (WNV) in Europe, with sporadic human and/or equines cases. However, recent events indicate that this picture is changing, raising the possibility that Europe could experience a modification in the virus' circulation patterns. We used an existing model of WNV circulation between Southern Europe and West Africa to estimate the sample size of equivalent West Nile surveillance systems, either passive (based upon horse populations and sentinel veterinarians) or active (sentinel horses, sentinel chickens, or WNV genome detection in trapped mosquito pools). The costs and calendar day of first detection of these different surveillance systems were compared under three different epidemiological scenarios: very low level circulation, low level recurrent circulation, and epidemic situation. The passive surveillance of 1000 horses by specialized veterinarian clinics appeared to be the most cost-effective system in the current European context, and estimated median dates of first detection appeared consistent with recent field observations. Our results can be used to optimize surveillance designs for different epidemiological requirements. © Copyright 2011, Mary Ann Liebert, Inc.


Eschbaumer M.,Institute of Diagnostic Virology | Wackerlin R.,Institute of Diagnostic Virology | Savini G.,Instituto G Caporale | Zientara S.,Laboratoire Of Sante Animale | And 4 more authors.
Vaccine | Year: 2011

Five cattle and five sheep that had never been exposed to bluetongue virus (BTV), as well as ten animals that had been experimentally infected with BTV-8, were inoculated with BTV-1. Previous exposure to BTV-8 did not prevent a second infection with another serotype. After the experiment, the BTV-1 preparation was found to be contaminated with BTV-15. The inoculum and blood samples taken during the experiment were analysed by serotype-specific real-time RT-PCR. There was 100-fold less BTV-15 than BTV-1 in the inoculum. Unexpectedly, BTV-15 dominated the infection in cattle that had previously been exposed to BTV-8. In sheep of both groups, on the other hand, BTV-1 prevailed over the contaminant. Regardless of the outcome, the incident demonstrates the need for a thorough contamination screening of virus preparations. For this purpose, two type-specific RT-PCR primer sets for each of the 24 established BTV serotypes as well as Toggenburg Orbivirus were designed. © 2011 Elsevier Ltd.

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