Highly pathogenic avian influenza (HPAI) risk management requires efficient surveillance of the infection in wild birds for early warning purposes. In this study, our aim was to describe the spread ...of continent‐wide infection cases using a fireworks model and therefore improve current surveillance systems. The fireworks model is a metaphor illustrating the spread of HPAI as a point source epizootic. The approach is based on early detection of the outbreak seeds (sparks from the fireworks) and uses a predictive model of the probability of the occurrence of new cases following a seed introduction; this then determines the spatiotemporal perimeter for intense surveillance investigations. For a case study, we used surveillance data on HPAI H5N1 in wild birds across Europe between 2005 and 2010 to describe the outbreaks and determine the success of the case detection used to inform management of the disease. The fireworks description assumes simultaneous introductions of ‘seeds’ of cases, which then ‘explode’ in local foci but do not merge into a progressive disease wave. This model fits the data well. Using this predictive approach for HPAI cases in EU countries, we found that the investigation radius needed to achieve a detection level of 90% of new cases after an outbreak ranged from 10 km to more than 300 km, depending on the outbreak pattern. Based on these findings, the fireworks approach can be a valuable method for identifying the perimeters and risk areas to be targeted for enhanced surveillance. The rationale of the fireworks approach is quite generic and can easily be adapted to different situations and contexts.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
In a previous study, three of the authors designed a one-dimensional model to simulate the propagation of rabies within a growing fox population; the influence of various parameters on the epidemic ...model was studied, including oral-vaccination programmes. In this work, a two-dimensional model of a fox population having either an exponential or a logistic growth pattern was considered. Using numerical simulations, the efficiencies of two prophylactic methods (fox contraception and vaccination against rabies) were assessed, used either separately or jointly. It was concluded that far lower rates of administration are necessary to eradicate rabies, and that the undesirable side-effects of each programme disappear, when both are used together.
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•Ruminant pathogens were prioritised to target surveillance reasonably in Europe.•A light, simple and direct email-based method was used to gather experts’ opinions.•Several experts in wildlife ...health throughout Europe took part in the survey.•A final list of six pathogens was set up for targeted field surveillance.•Preparedness should rely on such priority lists, but also on other approaches.
This study attempted to develop a list of priority pathogens. It is part of a European Union (EU) project dedicated to the surveillance of emerging or re-emerging pathogens of wildlife. Partners of the consortium established an initial list of 138 pathogens of concern, which was reduced to a smaller list of 65 pathogens likely to affect ruminants (i.e., the most costly animal group in the EU over the last 15 years). These 65 pathogens underwent a two-step, expert-based risk analysis: 92 experts graded them with respect to their global importance for animal welfare, species conservation, trade/economic impacts and public health. In step 2, the top 15 pathogens from step 1 were assessed by 69 experts considering seven weighted epidemiological criteria (pathogen variability, host specificity, potential for contagion, speed of spread, presence in Europe, difficulty of surveillance in wildlife and persistence in the environment) for which four options were possible. The responses concerned a wide geographic coverage. The resulting top-list pathogens were ranked as follows: 1. Salmonella enterica, 2. Coxiella burnetii, 3. foot-and-mouth disease virus, 4. Mycobacterium bovis, 5. bluetongue virus, and 6. European tick-borne encephalitis virus. The influence of the characteristics of the respondents, the importance of the levels of uncertainty/variability and the implication of the results are discussed. This work highlights the relevance of developing such lists for preparedness.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We report the first two cases of pulmonary presence of leptospires in apparently healthy rats captured in a city park in Lyon (France). Only renal carriage of Leptospira has been described in the ...literature. Blood serology was performed in parallel with molecular and histological analyses of the kidney and lung samples. We isolated leptospires from the kidneys of two out of three seropositive wild rats. These results were confirmed by specific detection of pathogenic Leptospira by real-time PCR. Moreover, Leptospira DNA was detected in lung tissues. Immunohistochemistry and Warthin-Starry staining revealed that leptospires were present on the surface of the ciliated epithelium of the bronchi. Using PCR of the rrs (16S) gene and Multispacer Sequence Typing, DNA extracts of the kidney and lung were identified as belonging to Leptospira interrogans serovar Icterohaemorrhagiae “CHU Réunion.” This first observation of the presence Leptospira in the lung with simultaneous renal carriage will require further study in future on several target organs to gain a better understanding of the Leptospira infection in wild rat.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Hochberg and co-workers have predicted that an increase in host adult mortality due to parasites is balanced by an earlier age at first reproduction. In polygynous species we hypothesize that such a ...pattern would lead to diverging selection pressure on body size between sexes and increased sexual size dimorphism. In polygynous mammals, male body size is considered to be an important factor for repro- ductive success. Thus, under the pressure of a virulent infection, males should be selected for rapid growth and/or higher body size to be able to compete successfully as soon as possible with opponents. In contrast, under the same selection pressure, females should be selected for lighter adult body size or rapid growth to reach sexual maturity earlier.We investigated this hypothesis in the domestic cat Felis catus. Orange cats have greater body size dimorphism than non-orange cats. Orange females are lighter than non-orange females, and orange males are heavier than non-orange males. Here, we report the extent to which orange and non-orange individuals differ in infection prevalence for two retroviruses, feline immunode- ciency virus (FIV) and feline leukaemia virus (FeLV). FIV is thought to be transmitted almost exclusively through aggressive contacts between individuals, whereas FeLV transmission occurs mainly through social contacts. The pattern of infection of both diseases is consistent with the higher aggressiveness of orange cats. In both sexes, orange cats are significantly more infected by FIV, and tend to be less infected by FeLV than other cats. The pattern of infection is also consistent with an earlier age at first reproduction in orange than in non-orange cats, at least for females. These results suggest that microparasitism may have played an important role in the evolution of sexual size dimorphism of domestic cats.
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Density-dependent and climatic factors affect reproduction and dynamics of wild ungulates. Parasites can also decrease reproductive success through either a direct abortive effect or a negative ...impact on host growth and body condition. However, few studies have investigated the effect of parasitism on fecundity of ungulates in natural conditions. We studied three bacterial infections caused by Salmonella enterica serovar Abortusovis, Chlamydophila abortus and Coxiella burnetii. These bacteria are leading causes of reproductive failure in sheep, goat and cattle, which raises the question of their influence on population dynamics of wild ungulates. A long-term study of demography and epidemiology of an alpine chamois (Rupicapra rupicapra, L.) population (Les Bauges Reserve, France) and a generalized linear modeling approach were used to analyze the reproductive success of chamois according to population density, weather conditions and the prevalence of antibodies against the three bacteria in females. This approach enabled us to identify the confounding effect of weather and parasitism on fecundity in a natural population. After accounting for density, the prevalence of antibodies against the three bacteria explained 36% of the annual variation in reproductive success, and weather conditions explained an additional 31%. This study was, to our knowledge, the first to compare the decrease in fecundity due to bacterial infections and weather conditions in a population of wild mountain ungulates.
BACKGROUND: Hantaviruses are single-stranded RNA viruses, which are transmitted to humans primarily via inhalation of aerosolised virus in contaminated rodent urine and faeces. Whilst infected ...reservoir hosts are asymptomatic, human infections can lead to two clinical manifestations, haemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS), with varying degrees of clinical severity. The incidence of rodent and human cases of Seoul virus (SEOV) in Europe has been considered to be low, and speculated to be driven by the sporadic introduction of infected brown rats (Rattus norvegicus) via ports. METHODS: Between October 2010 and March 2012, 128 brown rats were caught at sites across the Lyon region in France. RESULTS: SEOV RNA was detected in the lungs of 14% (95% CI 8.01 – 20.11) of brown rats tested using a nested pan-hantavirus RT-PCR (polymerase gene). Phylogenetic analysis supports the inclusion of the Lyon SEOV within Lineage 7 with SEOV strains originating from SE Asia and the previously reported French & Belgian SEOV strains. Sequence data obtained from the recent human SEOV case (Replonges) was most similar to that obtained from one brown rat trapped in a public park in Lyon city centre. We obtained significantly improved recovery of virus genome sequence directly from SEOV infected lung material using a simple viral enrichment approach and NGS technology. CONCLUSIONS: The detection of SEOV in two wild caught brown rats in the UK and the multiple detection of SEOV infected brown rats in the Lyon region of France, suggests that SEOV is circulating in European brown rats. Under-reporting and difficulties in identifying the hantaviruses associated with HFRS may mask the public health impact of SEOV in Europe.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Les auteurs réunis sous l’égide de l’Académie vétérinaire de France ont étudié comment la littérature scientifique interroge le rapport entre l’émergence de zoonoses ou de nouvelles maladies ...infectieuses humaines et animales, d’une part et les pertes de biodiversité observées sous l’effet des pressions humaines d’autre part. L’examen de la littérature consultée décrit comment certains agents pathogènes peuvent passer du « réservoir » naturel sauvage à celui des animaux domestiques et aux populations humaines. L’exploitation et la destruction des milieux naturels comme les forêts primaires et les zones humides tropicales, ainsi que le rapprochement d’espèces consécutif, favorisent des contacts permettant le passage (direct ou via des réservoirs intermédiaires) d’agents pathogènes du réservoir sauvage aux humains, qui propagent ensuite ces agents sur la planète. Il existe toutefois une importante variabilité des modalités permettant le passage, puis la propagation locale et planétaire des agents pathogènes issus de la biodiversité. Il est prématuré de tirer des conclusions générales sur les relations que cette revue scientifique a examinées. L’article suggère néanmoins que l’approche pluridisciplinaire doit progresser tant dans le domaine de la recherche que dans celui des pratiques et de l’enseignement. Cette pluridisciplinarité implique une étroite collaboration entre les médecines vétérinaires et humaines, l’écologie de la santé, d’autres disciplines biologiques et environnementales, et les sciences humaines.
Les auteurs réunis sous l’égide de l’Académie Vétérinaire de France ont étudié comment la littérature scientifique interroge le rapport entre l’émergence de zoonoses ou de nouvelles maladies ...infectieuses humaines et animales, d’une part et les pertes de biodiversité observées sous l’effet des pressions humaines d’autre part. L’examen de la littérature consultée décrit comment certains agents pathogènes peuvent passer du «réservoir » naturel sauvage à celui des animaux domestiques et aux populations humaines. L’exploitation et la destruction des milieux naturels comme les forêts primaires et les zones humides tropicales, ainsi que le rapprochement d’espèces consécutif, favorisent des contacts permettant le passage (direct ou via des réservoirs intermédiaires) d’agents pathogènes du réservoir sauvage aux humains, qui propagent ensuite ces agents sur la planète. Il existe toutefois une importante variabilité des modalités permettant le passage, puis la propagation locale et planétaire des agents pathogènes issus de la biodiversité. Il est prématuré de tirer des conclusions générales sur les relations que cette revue scientifique a examinées. L’article suggère néanmoins que l’approche pluridisciplinaire doit progresser tant dans le domaine de la recherche que dans celui des pratiques et de l’enseignement. Cette pluridisciplinarité implique une étroite collaboration entre les médecines vétérinaires et humaines, l’écologie de la santé, d’autres disciplines biologiques et environnementales, et les sciences humaines.
The authors, under the aegis of the Veterinary Academy of France, studied how the scientific literature questions the relationship between the emergence of zoonosis or new human and animal infectious diseases and the loss of biodiversity observed under anthropogenic changes. This review describes how some pathogens can spill over from «wild reservoir » to domestic animal populations and human. The exploitation and destruction of natural environments such as primary forests and tropical wetlands, and closest proximity amongst species that is consecutive promote contacts that allow pathogens to circulate from the wild natural reservoirs to humans, who then spread these agents all over the world. However, there is a large array of modalities with regard to the transmission and further spread of pathogens from biodiversity. It is premature to draw general conclusions on these relationships from this review only. However, the study emphasizes the needs to strengthen a multidisciplinary approach in research as well as in practice and teaching. Such multi-disciplinary approach should involve close collaborations between veterinary and human medicines, ecology, other biological and environmental disciplines and the human sciences.
A retrospective study was conducted to identify and describe the distribution pattern of Leptospira serogroups in domestic animals in France. The population consisted of cattle herds and dogs with ...clinically suspected leptospirosis that were tested at the "Laboratoire des Leptospires" between 2008 and 2011. The laboratory database was queried for records of cattle and dogs in which seroreactivity in Leptospira microagglutination tests was consistent with a recent or current infection, excluding vaccine serogroups in dogs. A total of 394 cattle herds and 232 dogs were diagnosed with clinical leptospirosis, and the results suggested infection by the Leptospira serogroup Australis in 43% and 63%, respectively; by the Leptospira serogroup Grippotyphosa in 17% and 9%, respectively; and by the Leptospira serogroup Sejroe in 33% and 6%, respectively. This inventory of infecting Leptospira serogroups revealed that current vaccines in France are not fully capable of preventing the clinical form of the disease.
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