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

Anillamiento científico de aves y vigilancia de enfermedades: Garrapatas, excrementos y plumas para prevenir brotes epidémicos

Trabajo presentado al XXIV Congreso Español y VII Ibérico de Ornitología, celebrado en Cadiz del 13 al 17 de noviembre de 2019.Recientemente varias enfermedades infecciosas han causado mortalidades severas en aves silvestres en Europa, con impactos notables en las poblaciones de algunas especies, tanto especies comunes como el mirlo europeo (Turdus merula) en el caso de virus Usutu en el valle del Rin en Alemania, como en especies amenazadas, como el halcón peregrino (Falco peregrinus) en el caso de influenza aviar H5N8 en los Países Bajos y Bélgica. Por otra parte, las aves están implicadas en los ciclos epidemiológicos de zoonosis importantes como la influenza aviar o la fiebre del Nilo occidental, entre otras, siendo aquí crucial la predicción de brotes para prevenir posibles casos en humanos. Incluso los mismos anilladores están en riesgo de exposición o de contactar con patógenos emergentes transmitidos por vectores (mosquitos en el caso de la fiebre del Nilo, garrapatas en la fiebre hemorrágica de Crimea-Congo) o de forma directa (como Salmonella, Clamidia o influenza aviar). Preocupa también la creciente resistencia de las bacterias a los antibióticos, en cuya transmisión podrían participar aves expuestas a ambientes urbanos o aguas residuales. Por la amplia actividad de anillamiento en toda la Península, la multitud de especies capturadas y la variedad de hábitats en los que se realizan las capturas, muestras procedentes de los anillamientos pueden resultar claves para generar información que pueda ayudar a predecir la aparición de brotes y prevenir riesgos, tanto para anilladores como para las aves y el público en general. Algunas muestras que se generan de forma espontánea durante el proceso de anillamiento, como los excrementos que las aves depositan en las bolsas colectoras, pueden ser de gran utilidad a la hora de investigar la presencia de Salmonella y otras bacterias patógenas, así como la expansión de bacterias multi-resistentes. Otras muestras, cuya colección resulta poco invasiva para las aves, como la recogida de plumas en crecimiento durante la fase activa de muda y las garrapatas que pueden parasitar a las aves, han demostrado ser de gran utilidad para la detección de diferentes patógenos. En el caso de las garrapatas, los patógenos que pueden transmitir dependen de la especie de garrapata, lo cual significa que la identificación de las mismas y su distribución permiten predecir ciertos riesgos. En este trabajo recopilamos una lista de enfermedades que se pueden detectar en estas muestras, y presentamos una sencilla aplicación de móvil denominada “BirdTick” que permite el envío de fotos de garrapatas halladas en las aves, para su identificación y remisión para el correspondiente análisis. Estas líneas de trabajo forman parte de un proyecto que pretende crear una red de puntos de muestreo en anillamiento que permita trazar un mapa de riesgos tanto para las aves como para las personas.Peer reviewe

Infection and exposure to vector-borne pathogens in rural dogs and their ticks, Uganda

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: In rural parts of Africa, dogs live in close association with humans and livestock, roam freely, and usually do not receive prophylactic measures. Thus, they are a source of infectious disease for humans and for wildlife such as protected carnivores. In 2011, an epidemiological study was carried out around three conservation areas in Uganda to detect the presence and determine the prevalence of vector-borne pathogens in rural dogs and associated ticks to evaluate the risk that these pathogens pose to humans and wildlife. [Methods]: Serum samples (n=105), blood smears (n=43) and blood preserved on FTA cards (n=38) and ticks (58 monospecific pools of Haemaphysalis leachi and Rhipicephalus praetextatus including 312 ticks from 52 dogs) were collected from dogs. Dog sera were tested by indirect immunofluorescence to detect the presence of antibodies against Rickettsia conorii and Ehrlichia canis. Antibodies against R. conorii were also examined by indirect enzyme immunoassay. Real time PCR for the detection of Rickettsia spp., Anaplasmataceae, Bartonella spp. and Babesia spp. was performed in DNA extracted from FTA cards and ticks. [Results]: 99 % of the dogs were seropositive to Rickettsia spp. and 29.5 % to Ehrlichia spp. Molecular analyses revealed that 7.8 % of the blood samples were infected with Babesia rossi, and all were negative for Rickettsia spp. and Ehrlichia spp. Ticks were infected with Rickettsia sp. (18.9 %), including R. conorii and R. massiliae; Ehrlichia sp. (18.9 %), including E. chaffeensis and Anaplasma platys; and B. rossi (1.7 %). Bartonella spp. was not detected in any of the blood or tick samples. [Conclusions]: This study confirms the presence of previously undetected vector-borne pathogens of humans and animals in East Africa. We recommend that dog owners in rural Uganda be advised to protect their animals against ectoparasites to prevent the transmission of pathogens to humans and wildlife.This study received partial support from the project CGL2010-17931.Peer Reviewe

Re-emergence of bovine piroplasmosis in Hungary: has the etiological role of Babesia divergens been taken over by B. major and Theileria buffeli?

[Background]: The prevalence of bovine babesiosis caused by Babesia divergens has been declining during the past decades in northeastern Hungary, and no cases have been observed since 2008. Infections of cattle with B. major and Theileria buffeli were hitherto reported in southern and western Europe. In other parts of the globe, there is evidence of emergence and a growing clinical importance of T. buffeli and closely related genotypes of the T. orientalis complex. [Findings]: In a herd of 88 beef cattle kept in northeastern Hungary, bovine piroplasmosis was diagnosed in nine animals through the examination of blood smears or by molecular methods. B. major was identified in five animals, two of which died. In addition, four cattle harboured T. buffeli, and one of these animals was anaemic. Despite their presence, a contributory role of Anaplasma marginale and A. phagocytophilum could not be established in the disease cases. [Conclusions]: In this study B. major and bovine theileriosis is reported for the first time in central-eastern Europe, where clinical cases were associated with a mild winter.This study was partially funded by EU grant FP7-261504 EDENext and is catalogued by the EDENext Steering Committee as EDENext258.Peer Reviewe

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

The effects of host and environmental factors on tick parasitism in red deer are modulated by sex

Póster presentado al Joint 8th International Ticks and Tick-borne Pathogens and 12th Biennial Society for Tropical Veterinary Medicine Conference, celebradas en Cape Town (Sudafrica) del 24 al 29 de agosto de 2014.[Objectives]: Host individual, host population and environmental factors interact to modulate parasite abundance in hosts. Since size dimorphism, life history traits and segregation observed in red deer (Cervus elaphus) are linked to sex and this ungulate species constitutes a highly relevant host for adult exophilic ticks, it was hypothesized that tick parasitism on stags and hinds would be differentially influenced by each of these factors. [Method]: Ticks from 306 red deer were collected during 7 years in a red deer population. By generalized linear models we modelled tick abundance on deer with 20 potential predictors. Three models were developed: one for stags, another for hinds, and one combining data from both sexes 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. [Conclusions]: Results support for sex-biased differences in tick parasitism in red deer. The higher weight of host individual and population factors in the model for stags show that intrinsic deer factors more strongly explain tick burden than environmental host-seeking tick abundance. In contrast, environmental variables better explained tick burdens in hinds.We thank gamekeepers, project AGL2010‐20730‐C02 (Spanish Ministry for Economy and Competitiveness‐MINECO) and EU FP7 grant ANTIGONE (278976). F. Ruiz‐Fons & P. Acevedo are supported by MINECO.Peer Reviewe

High degree of mitochondrial gene heterogeneity in the bat tick species Ixodes vespertilionis, I. ariadnae and I. simplex from Eurasia

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License.-- et al.[Background]: Phylogeographical studies allow precise genetic comparison of specimens, which were collected over large geographical ranges and belong to the same or closely related animal species. These methods have also been used to compare ticks of veterinary-medical importance. However, relevant data are missing in the case of ixodid ticks of bats, despite (1) the vast geographical range of both Ixodes vespertilionis and Ixodes simplex, and (2) the considerable uncertainty in their taxonomy, which is currently unresolvable by morphological clues. [Methods]: In the present study 21 ticks were selected from collections or were freshly removed from bats or cave walls in six European and four Asian countries. The DNA was extracted and PCRs were performed to amplify part of the cytochrome oxidase I (COI), 16S and 12S rDNA genes, followed by sequencing for identification and molecular-phylogenetic comparison. [Results]: No morphological differences were observed between Ixodes vespertilionis specimens from Spain and from other parts of Europe, but corresponding genotypes had only 94.6 % COI sequence identity. An I. vespertilionis specimen collected in Vietnam was different both morphologically and genetically (i.e. with only 84.1 % COI sequence identity in comparison with I. vespertilionis from Europe). Two ticks (collected in Vietnam and in Japan) formed a monophyletic clade and shared morphological features with I. ariadnae, recently described and hitherto only reported in Europe. In addition, two Asiatic specimens of I. simplex were shown to differ markedly from European genotypes of the same species. Phylogenetic relationships of ticks showed similar clustering patterns with those of their associated bat host species. [Conclusions]: Although all three ixodid bat tick species evaluated in the present study appear to be widespread in Eurasia, they exhibit pronounced genetic differences. Data of this study also reflect that I. vespertilionis may represent a species complex.Financial support was provided by OTKA 115854, by OTKA K112440, by the 9877- 3/2015/FEKUT grant of the Hungarian Ministry of Human Resources and by the national project grant from the Ministry of Education, Science and Technological Development of the Republic of Serbia (Project No. 173006). TPeer Reviewe

Molecular screening for Anaplasmataceae in ticks and tsetse flies from Ethiopia

Hard ticks and tsetse flies are regarded as the most important vectors of disease agents in Sub-Saharan Africa. With the aim of screening these blood-sucking arthropods for vector-borne pathogens belonging to the family Anaplasmataceae in South-Western Ethiopia, four species of tsetse flies (collected by traps) and seven species of ixodid ticks (removed from cattle) were molecularly analysed. DNA was extracted from 296 individual ticks and from 162 individuals or pools of tsetse flies. Besides known vector–pathogen associations, in Amblyomma cohaerens ticks sequences of Anaplasma marginale and A. phagocytophilum were detected, the latter for the first time in any ticks from cattle in Africa. In addition, part of the gltA gene of Ehrlichia ruminantium was successfully amplified from tsetse flies (Glossina pallidipes). First-time identification of sequences of the above pathogens in certain tick or tsetse fly species may serve as the basis of further epidemiological and transmission studies

Usutu virus in migratory song thrushes, Spain

Letter to the Editor.This research was supported by European Union grants 278976 from the following programs of the EMIDA ERANET (Coordination of European Research on Emerging and Major Infectious Diseases of Livestock; www.emida-era. net): ANTIGONE (Anticipating the Global Onset of Novel Epidemics) and APHAEA (Harmonised Approaches in Monitoring Wildlife Population Health).Peer Reviewe

Usutu Virus in Migratory Song Thrushes, Spain

Our data imply that introduction of USUV (and potentially other flaviviruses such as West Nile virus lineage 2, which has not yet been detected in Spain) from Northern Europe, in addition to local endemicity and introduction from Africa, occurs, and that the zoonotic European USUV strain may be co-circulating with strains of African origin. At this time, it is not clear whether USUV strains of Spanish/African lineage differ in virulence for humans from strains from the European/African lineage. However, virus introduction by northern migrants, in combination with locally favorable conditions for vector populations, implies a risk for virus amplification and transmission and disease outbreaks in humans and horses outside the currently established mosquito-trapping period (May-October) of targeted flavivirus surveillance programs.Fil: Höfle, Ursula. Consejo Superior de Investigaciones Cientificas; España;Fil: Gamino, Virginia. Consejo Superior de Investigaciones Cientificas; España;Fil: Fernández de Mera, Isabel G.. Consejo Superior de Investigaciones Cientificas; España;Fil: Mangold, Atilio Jose. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria, Rafaela; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina;Fil: Ortíz, José Antonio. Consejo Superior de Investigaciones Cientificas; España;Fil: de la Fuente, José. Oklahoma State University; Estados Unidos de América