Applications of epidemiology in PRRS control

[ES]: Aunque el síndrome reproductivo y respiratorio porcino (PRRS) fue descrito por primera vez en la década de los 80, en menos de 30 años esta enfermedad ha pasado a convertirse en una de las patologías más importantes para el sector porcino. Los esfuerzos invertidos en este periodo en su investigación han permitido la identificación de su agente causal y de sus ciclos epidemiológicos, así como el desarrollo de nuevas herramientas diagnósticas y vacunas. En la actualidad cualquier programa de lucha frente al virus del PRRS debe estar basado en la combinación de todas las herramientas disponibles con el objetivo fundamental de romper los ciclos de transmisión, para lo cual es imprescindible un adecuado conocimiento de la epidemiología de la enfermedad.[EN]: Even though the porcine reproductive and respiratory syndrome was first reported in the 80’s, in less than 30 years the disease has become one of the most important diseases affecting the swine industry worldwide. Efforts invested since then in research have allowed the identification of its causative agent and its epidemiological cycles as well as the development of new diagnostic tools and vaccines. Nowadays effective control programs against PRRS virus must be based on the combined used of all available tools with the main aim of disrupting the transmission cycles; an adequate knowledge of the epidemiology of the disease is cornerstone to achieve this goal.Peer Reviewe

Depredación de Timon lepidus por gato asilvestrado

La financiación de estos trabajos ha sido posible gracias a los proyectos “Interacciones ecológicas en comunidades de carnívoros ibéricos” (CGL2009-10741, financiado por el Plan Nacional de I+D y fondos FEDER) y “Hunting for sustainability” (HUNT, financiado por la Comisión Europea dentro del 7º Programa Marco para Investigación y Desarrollo Tecnológico).Peer Reviewe

Leishmania infantum in free-ranging hares, Spain, 2004-2010

Iberian hares (Lepus granatensis) were recently deemed responsible for an outbreak of human leishmaniasis affecting metropolitan Madrid, Spain. However, the reservoir potential of hares in Europe is poorly known. We report a retrospective survey on Leishmania infantum, the causal agent of zoonotic endemic leishmaniasis in the Mediterranean basin, infection status of Iberian, European (Le. europaeus) and Broom (Le. castroviejoi) hares in Spain. Spleen samples from 94 hares were tested by polymerase chain reaction. Sequencing and restriction fragment length polymorphism (RFLP) assays were performed on positive samples and RFLP patterns compared with those of strains reported in the scientific literature. DNA prevalence in hare spleen samples was 43.6% (95% confidence interval: 33.6-53.6). In all six regions studied at least one positive sample was found. RFLP revealed existence of specific hare strains of L. infantum differing from those reported in wild carnivores in Spain. The widespread presence of L. infantum in the most abundant Spanish hare species and the recent evidence of the ability of naturally infected hares to transmit the pathogen to Phlebotomus perniciosus, its main vector in the western Mediterranean, suggest that hares may have an unexpected role in the epidemiology of L. infantum in Spain.This study is a contribution to project POII09-0141-8176 (JCCM and EU-FEDER) and EU grants ANTIGONE (278976) and APHAEA (EMIDA ERA-NET). F. Ruiz-Fon acknowledges a Juan de la Cierva contract (Ministerio de Economía y Competitividad).Peer Reviewe

Wild boar: an increasing concern for Aujeszky's disease control in pigs?

<p>Abstract</p> <p>Background</p> <p>The goal of this study was describing the temporal evolution of Aujeszky's disease virus (ADV) contact prevalence among Eurasian wild boar (<it>Sus scrofa</it>) populations under different management regimes and contact likelihoods with domestic pigs. Given the recent increase in wild boar abundance throughout Europe, we hypothesized that wild boar contact with ADV would remain stable in time even after significant reduction of ADV prevalence in domestic pigs.</p> <p>Results</p> <p>Sera from 1659 wild boar were collected from 2000 to 2010 within 6 areas of the Iberian Peninsula and tested for the presence of antibodies against ADV by ELISA. According to sampling date, wild boar were grouped into three time periods. ADV prevalence was compared through period both globally and by geographic area. Overall seroprevalence for the ten-year study period was 49.6 ± 2.4%. The highest seroprevalence was recorded in areas with intense wild boar management. The annual proportion of positive wild boar sampling sites remained stable through the study period, while the percentage of domestic pig AD positive counties decreased from 70% in 2003 to 1.7% in 2010.</p> <p>Conclusions</p> <p>Results presented herein confirmed our hypothesis that ADV would remain almost stable in wild boar populations. This evidences the increasing risk wild boar pose in the final stages of ADV eradication in pigs and for wildlife conservation.</p

Assessment of the capacity of a pyrophosphate-based mouth rinse to inhibit the formation of supragingival dental calculus. a randomized double-blind placebo-controlled clinical trial

This study aimed to analyze the efficacy of an anti-calculus mouth rinse and its possible adverse effects on the mucosa and teeth. This randomized double-blind placebo-controlled clinical trial included 40 patients with treated and managed periodontal disease, all with a history of rapid calculus formation. Patients used a pyrophosphate-based test mouth rinse (B) or a placebo (A). A range of parameters were measured for: saliva (saliva flow, pH and chemical composition); calculus (Volpe-Manhold [V-M] index, weight, and volume); adverse effects on mucosa and teeth; and the patients? subjective perceptive of mouth rinse efficacy. The test mouth rinse B produced reductions in urea, uric acid, and phosphorous, calcium, saliva flow, and increases in pH. V-M index and calculus weight decreased after using the test mouth rinse. Calculus volume decreased with both mouth rinses. No changes to the mucosa or teeth were observed. Patients perceived that the test mouth rinse was more effective. The test/B and placebo mouth rinses both modified certain parameters in saliva composition, particularly reductions in urea, uric acid, and phosphorous. Calcium tended to increase after using the test-B mouth rinse. The results did not demonstrate the anticalculus efficacy of the pyrophosphate-based mouth rinse or positive effects on saliva flow or composition. This field requires further research, as no product has been developed that prevents calculus formation completely

Bluetongue virus serotypes 1 and 4 in red deer, Spain

We studied the potential of red deer as bluetongue maintenance hosts and sentinels. Deer maintained detectable bluetongue virus (BTV) serotype 4 RNA for 1 year after the virus was cleared from livestock. However, the virus was not transmitted to yearlings. BTV serotype 1 RNA was detected in red deer immediately after its first detection in cattle.This study was funded by the Spanish Ministry of Natural, Rural and Marine Environment (RASVE 274/2007, and an agreement between Organismo Autónomo de Parques Nacionales (OAPN), Dirección General de Recursos Agricolas y Ganaderos (DGRAG), and Consejo Superior de Investigaciones Cientificas (CSIC). F.R.-F. is supported by a postdoctoral contract of the Instituto de Salud Carlos III of the Spanish government.Peer Reviewe

Culicoides species communities associated with wild ruminant ecosystems in Spain: Tracking the way to determine potential bridge vectors for arboviruses

This is an open access article distributed under the terms of the Creative Commons Attribution License.-- et al.The genus Culicoides Latreille 1809 is a well-known vector for protozoa, filarial worms and, above all, numerous viruses. The Bluetongue virus (BTV) and the recently emerged Schmallenberg virus (SBV) are responsible for important infectious, non-contagious, insect-borne viral diseases found in domestic ruminants and transmitted by Culicoides spp. Both of these diseases have been detected in wild ruminants, but their role as reservoirs during the vector-free season still remains relatively unknown. In fact, we tend to ignore the possibility of wild ruminants acting as a source of disease (BTV, SBV) and permitting its reintroduction to domestic ruminants during the following vector season. In this context, a knowledge of the composition of the Culicoides species communities that inhabit areas where there are wild ruminants is of major importance as the presence of a vector species is a prerequisite for disease transmission. In this study, samplings were conducted in areas inhabited by different wild ruminant species; samples were taken in both 2009 and 2010, on a monthly basis, during the peak season for midge activity (in summer and autumn). A total of 102,693 specimens of 40 different species of the genus Culicoides were trapped; these included major BTV and SBV vector species. The most abundant vector species were C. imicola and species of the Obsoletus group, which represented 15% and 11% of total numbers of specimens, respectively. At the local scale, the presence of major BTV and SBV vector species in areas with wild ruminants coincided with that of the nearest sentinel farms included in the Spanish Bluetongue Entomological Surveillance Programme, although their relative abundance varied. The data suggest that such species do not exhibit strong host specificity towards either domestic or wild ruminants and that they could consequently play a prominent role as bridge vectors for different pathogens between both types of ruminants. This finding would support the hypothesis that wild ruminants could act as reservoirs for such pathogens, and subsequently be involved in the reintroduction of disease to livestock on neighbouring farms.This study was supported by the project FAU 2008-0019 from Instituto Nacional de Investigaciones Agrarias, and was partially funded by EU grant GOCE-2003-010284 EDENext and is cataloged by the EDENext Steering Committee as EDENext429 (http://www.edenext.eu). F. Ruiz-Fons is supported by the Spanish Ministry for the Economy and Competitiveness through a Juan de la Cierva postdoctoral contract.Peer Reviewe

Spatial and Temporal Evolution of Bluetongue Virus in Wild Ruminants, Spain

We confirmed the emergence of bluetongue virus (BTV) in 5 wild ruminant species in Spain. BTV seroprevalence was high and dispersed with time, with a south-to-north gradient. Our results suggest a complex epidemiology of BTV and underline the need for additional research on wildlife in Europe

Bluetongue Virus Serotypes 1 and 4 in Red Deer, Spain

We studied the potential of red deer as bluetongue maintenance hosts and sentinels. Deer maintained detectable bluetongue virus (BTV) serotype 4 RNA for 1 year after the virus was cleared from livestock. However, the virus was not transmitted to yearlings. BTV serotype 1 RNA was detected in red deer immediately after its first detection in cattle

Sex-biased differences in the effects of host individual, host population and environmental traits driving tick parasitism in red deer

The interactions between host individual, host population, and environmental factors modulate parasite abundance in a given host population. Since adult exophilic ticks are highly aggregated in red deer (Cervus elaphus) and this ungulate exhibits significant sexual size dimorphism, life history traits and segregation, we hypothesized that tick parasitism on males and hinds would be differentially influenced by each of these factors. To test the hypothesis, ticks from 306 red deer-182 males and 124 females-were collected during 7 years in a red deer population in south-central Spain. By using generalized linear models, with a negative binomial error distribution and a logarithmic link function, we modeled tick abundance on deer with 20 potential predictors. Three models were developed: one for red deer males, another for hinds, and one combining data for males and females and including >sex> as factor. Our rationale was that if tick burdens on males and hinds relate to the explanatory factors in a differential way, it is not possible to precisely and accurately predict the tick burden on one sex using the model fitted on the other sex, or with the model that combines data from both sexes. Our results showed that deer males were the primary target for ticks, the weight of each factor differed between sexes, and each sex specific model was not able to accurately predict burdens on the animals of the other sex. That is, results support for sex-biased differences. The higher weight of host individual and population factors in the model for males show that intrinsic deer factors more strongly explain tick burden than environmental host-seeking tick abundance. In contrast, environmental variables predominated in the models explaining tick burdens in hinds.This study was supported by project AGL2010-20730-C02 (Spanish Ministry for Economy and Competitiveness) and EU FP7 grant ANTIGONE (278976). F. Ruiz-Fons is supported by a Juan de la Cierva contract from the Spanish Ministry for Economy and Competitiveness. P. Acevedo is funded from the SFRH/BPD/90320/2012 post-doctoral grant by Portuguese Fundação para a Ciência e a Tecnologia (FCT) and European Social Fund.Peer Reviewe