Deforestation and Bovine Rabies Outbreaks in Costa Rica, 1985-2020.

In Latin America, rabies virus has persisted in a cycle between Desmodus rotundus vampire bats and cattle, potentially enhanced by deforestation. We modeled bovine rabies virus outbreaks in Costa Rica relative to land-use indicators and found spatial-temporal relationships among rabies virus outbreaks with deforestation as a predictor.

Virome analysis of Desmodus rotundus tissue samples from the Amazon region.

BACKGROUND: Bats are renowned for harboring a high viral diversity, their characteristics contribute to emerging infectious diseases. However, environmental and anthropic factors also play a significant role in the emergence of zoonotic viruses. Metagenomic is an important tool for investigating the virome of bats and discovering new viruses. RESULTS: Twenty-four families of virus were detected in lung samples by sequencing and bioinfomatic analysis, the largest amount of reads was focused on the Retroviridae and contigs assembled to Desmodus rotundus endogenous retrovirus, which was feasible to acquire complete sequences. The reads were also abundant for phages. CONCLUSION: This lung virome of D. rotundus contributes valuable information regarding the viral diversity found in bats, which is useful for understanding the drivers of viral cycles and their ecology in this species. The identification and taxonomic categorization of viruses hosted by bats carry epidemiological significance due to the potential for viral adaptation to other animals and humans, which can have severe repercussions for public health. Furthermore, the characterization of endogenized viruses helps to understanding the host genome and the evolution of the species.

Dispersion and diversification of Lyssavirus rabies transmitted from haematophagous bats Desmodus rotundus: a phylogeographical study.

Rabies is worldwide zoonosis caused by Lyssavirus rabies (RABV) a RNA negative sense virus with low level of fidelity during replication cycle. Nucleoprotein of RABV is the most conserved between all five proteins of the virus and is the most used gene for phylogenetic and phylogeographic studies. Despite of rabies been very important in Public Health concern, it demands continuous prophylactic care for herbivores with economic interest, such as cattle and horses. The main transmitter of RABV for these animals in Brazil is the hematophagous bats Desmodus rotundus. The aim of this study was to determine the dispersion over time and space of RABV transmitted by D. rotundus. Samples of RABV from the State of São Paulo (SP), Southeast Brazil isolated from the central nervous system (CNS) of cattle, were submitted to RNA extraction, RT-PCR, sequencing and phylogeographic analyzes with BEAST (Bayesian Evolutionary Analysis Sampling Trees) v 2.5 software. Was possible to identify high rate of diversification in starts sublineages of RABV what are correlated with a behavior of D. rotundus, the main transmitter of rabies to cattle. This study also highlights the importance of continuous monitoring of genetic lineages of RABV in Brazil.

Epidemiology and Control of Rabies in Cattle and Equines in Rondônia State, a Brazilian's Legal Amazon Area.

Rabies is a fatal neglected tropical zoonosis, and its significance for domestic herbivores in the rural cycle is probably associated with rainforest deforestation, livestock, and agricultural expansion. This epidemiological survey aimed to study the occurrence of rabies in bovines and equines in the state of Rondônia, located in the Brazilian's Legal Amazon, between the years 2002 and 2021, correlating these findings with the prophylactic strategies adopted by the local sanitary agency for rabies control. During this period, 201 cases were observed in bovines and 23 in equines. A downward trend in rabies incidence was observed for both domestic herbivores. Rabies did not show a higher occurrence in any specific time of the year, and epidemic periods varied during some years for bovines and equines. Using the Generalized estimating equations (GEE) method, a multiple model approach was obtained with the explanatory variables significantly associated with the decrease in rabies incidence in cattle and horses during the study period: the ratio of treated bats and ratio of vaccine doses sold. Furthermore, the ratio of printed educative material was positively associated with rabies incidence. Despite a decreasing trend in rabies occurrences in this Amazon rainforest area, likely due to the actions taken by the animal sanitary agency, rabies remains endemic and requires monitoring, as well as prophylactic strategies to control this disease.

Novel Borrelia Genotypes from Brazil Indicate a New Group of Borrelia spp. Associated with South American Bats.

The bacterial genus Borrelia comprises vector-borne spirochetes that have been classified into three major groups: the relapsing fever group (RFG), the Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner sensu lato group (Bbsl), and the reptile-monotreme group (RMG). All three groups have been associated mainly with ticks and wild animals, especially rodents, birds, and reptiles. Here, we searched for Borrelia infection among 99 vampire bats [Desmodus rotundus (É. Geoffroy)] (Chiroptera: Phyllostomidae) from the Brazilian semiarid region. Through molecular investigation of bat internal organs, haplotypes of a potentially novel Borrelia organism were detected in 5% (5/99) of the bats. Borrelia DNA was detected in the liver, blood, spleen, kidney and brain, suggesting a systemic infection. Phylogenetic analyses inferred from partial sequences of the borrelial rrs and flaB genes indicated that the vampire bat-associated Borrelia sp. of this study form a monophyletic group with a newly reported Borrelia associated with a Colombia bat, distinct from the three main currently recognized groups of Borrelia spp., Bbsl, RFG, and RMG. These novel bat-associated Borrelia spp. from South America might have arisen through an independent event along the borrelial evolutionary history, since previous molecular reports of Borrelia organisms in bats or bat-associated ticks from Africa, Europe, and North America were all classified in the RFG.

Drivers of Spatial Expansions of Vampire Bat Rabies in Colombia.

Spatial expansions of vampire bat-transmitted rabies (VBR) are increasing the risk of lethal infections in livestock and humans in Latin America. Identifying the drivers of these expansions could improve current approaches to surveillance and prevention. We aimed to identify if VBR spatial expansions are occurring in Colombia and test factors associated with these expansions. We analyzed 2336 VBR outbreaks in livestock reported to the National Animal Health Agency (Instituto Colombiano Agropecuario-ICA) affecting 297 municipalities from 2000-2019. The area affected by VBR changed through time and was correlated to the reported number of outbreaks each year. Consistent with spatial expansions, some municipalities reported VBR outbreaks for the first time each year and nearly half of the estimated infected area in 2010-2019 did not report outbreaks in the previous decade. However, the number of newly infected municipalities decreased between 2000-2019, suggesting decelerating spatial expansions. Municipalities infected later had lower cattle populations and were located further from the local reporting offices of the ICA. Reducing the VBR burden in Colombia requires improving vaccination coverage in both endemic and newly infected areas while improving surveillance capacity in increasingly remote areas with lower cattle populations where rabies is emerging.

Trypanosoma cruzi DNA in Desmodus rotundus (common vampire bat) and Histiotus montanus (small big-eared brown bat) from Chile.

The protozoan Trypanosoma cruzi, the causative agent of Chagas disease, is transmitted by infected feces or consumption of blood-sucking triatomine insects to several mammalian orders including Chiroptera. In Chile, the distribution of several insectivorous and one hematophagous bat species overlaps with those of triatomine vectors, but the T. cruzi infection status of local chiropterans is unknown. In 2018, we live-captured bats from two protected areas in Chile to collect plagiopatagium tissue, feces and perianal swab samples, in search for T. cruzi-DNA by real time PCR assays using species-specific primers. In Pan de Azúcar island (∼26°S), we examined a roost of Desmodus rotundus (common vampire bat) and sampled tissue from 17 individuals, detecting T. cruzi-DNA in five of them. In Las Chinchillas National Reserve (∼31°S), we examined two roosts of Histiotus montanus (small big-eared brown bat), collecting feces or perianal swab samples from eight individuals, detecting T. cruzi-DNA in four of them. This is the first report of T. cruzi-DNA evidence in bat species from Chile. Both vector-borne and oral transmission are potential infection routes that can explain our results. Further investigation is needed for a better understanding of the role of bats in the T. cruzi transmission cycle.

Detection of coronavirus in vampire bats (Desmodus rotundus) in southern Brazil.

The vampire bat (Desmodus rotundus) is a haematophagous animal that feeds exclusively on the blood of domestic mammals. Vampire bat feeding habits enable their contact with mammalian hosts and may enhance zoonotic spillover. Moreover, they may carry several pathogenic organisms, including coronaviruses (CoVs), for which they are important hosts. The human pathogens that cause severe acute respiratory syndrome (SARS-CoV), Middle East respiratory syndrome (MERS-CoV) and possibly coronavirus disease 2019 (SARS-CoV-2) all originated in bats but required bridge hosts to spread into human populations. To monitor the presence of potential zoonotic viruses in bats, the present work evaluated the presence of CoVs in vampire bats from southern Brazil. A total of 101 vampire bats were captured and euthanized between 2017 and 2019 in Rio Grande do Sul state, southern Brazil. The brain, heart, liver, lungs, kidneys and intestines were collected and macerated individually. The samples were pooled and submitted to high-throughput sequencing (HTS) using the Illumina MiSeq platform and subsequently individually screened using a pancoronavirus RT-PCR protocol. We detected CoV-related sequences in HTS, but only two (2/101; 1.98%) animals had CoV detected in the intestines by RT-PCR. Partial sequences of RdRp and spike genes were obtained in the same sample and the RdRp region in the other sample. The sequences were classified as belonging to Alphacoronavirus. The sequences were closely related to alphacoronaviruses detected in vampire bats from Peru. The continuous monitoring of bat CoVs may help to map and predict putative future zoonotic agents with great impacts on human health.

Bat fly (Diptera: Streblidae) and common vampire bat (Chiroptera: Phyllostomidae) association in Honduras: prevalence, mean intensity, infracommunities and influence of the biological characteristics of the host

ABSTRACT Bat species present a series of attributes that makes them prone to being parasitized. Bat flies (Streblidae) are hematophagous ectoparasites exclusive to bats. Our study aimed to investigate the association of bat flies with the Common vampire bat, Desmodus rotundus (É. Geoffroy, 1810), in Honduras. We analyzed the effect of sex and age of the host on parasitism. Eight localities belonging to six departments were sampled in an altitudinal range between 50 and 995 m. Field data were obtained between May 2018 to November 2019 and 80 individuals were captured, from which 395 bat flies were extracted. Four species of bat flies were registered: Strebla wiedemanni Kolenati, 1856, Trichobius parasiticus Gervais, 1844, T. joblingi Wenzel, 1966 and T. caecus Edwards, 1948. Trichobius parasiticus presented the highest prevalence and mean intensity, followed by S. wiedemanni. Trichobius joblingi and T. caecus are new records of parasitism on D. rotundus for Honduras, although we consider as an accidental association. We recorded six types of infracommunities that parasitized 85% of the hosts. The prevalence and mean intensity was not affected by age and sex of the host for any bat fly species.

Bat fly (Diptera: Streblidae) and common vampire bat (Chiroptera: Phyllostomidae) association in Honduras: prevalence, mean intensity, infracommunities and influence of the biological characteristics of the host

Bat species present a series of attributes that makes them prone to being parasitized. Bat flies (Streblidae) are hematophagous ectoparasites exclusive to bats. Our study aimed to investigate the association of bat flies with the Common vampire bat, Desmodus rotundus (É. Geoffroy, 1810), in Honduras. We analyzed the effect of sex and age of the host on parasitism. Eight localities belonging to six departments were sampled in an altitudinal range between 50 and 995 m. Field data were obtained between May 2018 to November 2019 and 80 individuals were captured, from which 395 bat flies were extracted. Four species of bat flies were registered: Strebla wiedemanni Kolenati, 1856, Trichobius parasiticus Gervais, 1844, T. joblingi Wenzel, 1966 and T. caecus Edwards, 1948. Trichobius parasiticus presented the highest prevalence and mean intensity, followed by S. wiedemanni. Trichobius joblingi and T. caecus are new records of parasitism on D. rotundus for Honduras, although we consider as an accidental association. We recorded six types of infracommunities that parasitized 85% of the hosts. The prevalence and mean intensity was not affected by age and sex of the host for any bat fly species.

Análise quantitativa da receptividade a presença de abrigos de morcegos hematófagos Desmodus rotundus no município de São Pedro - SP / Quantitative analysis of the receptivity of the presence of vampire bats Desmodus rotundus shelters in the municipality of São Pedro - SP / Análisis cuantitativo de la receptividad de la presencia de hematophagus bat shelters Desmodus rotundus en el municipio de São Pedro - SP

O morcego hematófago Desmodus rotundus é o principal transmissor da raiva dos herbívoros, responsável por enormes prejuízos econômicos na pecuária na América Latina. Devido às interações de D. rotundus como meio ambiente, o risco da raiva nos herbívoros pode ser explicado pela vulnerabilidade e a receptividade do ambiente a capacidade do ecossistema albergar populações de D. rotundus. Utilizando de Sistema de Informações Geográficas foram analisados quantitativamente os seguintes determinantes de receptividade em que se encontravam os abrigos de morcegos hematófagos D. rotundus nomunicípio de SãoPedro - SP: tipo de solo e geologia, uso e cobertura do solo, declividade, hipsometria e proximidade a corpos de água. Foram localizados oito abrigos de D. rotundus, sendo dois abrigos naturais: uma gruta de arenito de Geologia Formação Piramboia e Neossolo Quartzarênico habitada por apenas um morcego, e outra gruta basáltica de Geologia Formação Itaqueri e Latossolo Vermelho-amarelo comum a população estimada de 100 D. rotundus. 75% dos abrigos estava em áreas de pastagem e cana de açúcar, seguido por áreas de vegetação nativa e vegetação riparia associada a pastagens. A presença de abrigos de D. rotundus em áreas de cultura canavieira e pastoril em quantidade superior a áreas de cobertura florestal ressalta a importância de oferta de abrigos artificiais em áreas agrícolas. A declividade do terreno em que se encontravam os abrigos variou de 3% a 29%. 62,5% dos abrigos estavam em áreas com baixas declividades com presença de pastagens, porém próximos a áreas de relevo mais escarpado e vegetação nativa com altitudes que variaram entre 475 m e 929 m. Todos os abrigos estavam localizados próximos a corpos d'agua. Apesar de corpos d'agua não constarem como fator de receptividade à presença de abrigos de D. rotundus no modelo epidemiológico indicado pelo Manual de Combate a Raiva dos Herbívoros - MAPA, no presente estudo a proximidade de todos os abrigos de D. rotundus a corpos d'agua evidencia a importância deste fator na receptividade ambiental à presença de abrigos destes morcegos, tornando relevante a inclusão deste fator nos modelos epidemiológicos de controle da raiva dos herbívoros. Desta forma faz-se necessária uma reavaliação da importância dos fatores de receptividade à presença de abrigos de D. rotundus nos modelos epidemiológicos, considerando a escala e particularidades de cada região em estudo, a inclusão outros tipos de formação geológica além da calcária para formação de abrigos naturais, a inclusão de novos tipos e cobertura de solo e a proximidade de corpos d'agua.

The vampire bat Desmodus rotundus is the main transmitter rabies in herbivores, responsible for enormous economic losses in livestock in Latin America. Due to interactions of D. rotundus with the environment, the risk of rabies in herbivores can be explained by the vulnerability and receptiveness of the environment to the capacity of the ecosystem to support populations of D. rotundus. Using a Geographic Information System, the following determinants of receptivity were quantitatively analyzed in which the vampire bat roosts D. rotundus were found in the city of São Pedro - SP: soil type and geology, land use and cover, slope, hypsometry and proximity to water bodies. Eight D. rotundus shelters were located, two of which were natural: as and stone cave of Piramboia Formation Geology and Quartzarênic Neosol inhabited by only one bat, and another basaltic cave of Itaqueri Formation Geology and Red-yellow Latosol with an estimated population of 100 D. rotundus. 75% of the shelters were in pasture and sugar cane areas, followed by areas of native vegetation and riparian vegetation associated with pastures. The presence of D. rotundus shelters in sugar cane and pastoral areas in a greater quantity than in forest cover areas highlights the importance of offering artificial shelters in agricultural areas. The slope of the land on which the shelters were located ranged from 3% to 29%. 62.5% of the shelters were in areas with lows lopes with the presence of pastures, but close to areas with more rugged relief and native vegetation with altitudes ranging between 475m and 929m. All shelters were located close to bodies of water. Although bodies of water do not appear as a factor of receptivity to the presence of shelters of D. rotundus in the epidemiological model indicated by the Herbivore Rabies Control Manual - MAPA, in the present study the proximity of all roosts of D. rotundus to water bodies highlights the importance of this factor in environmental receptivity to the presence of roosts for these bats, making it relevant to include this factor in epidemiological models for controlling rabies in herbivores. Thus, it is necessary to reassess the importance of factors of receptivity to the presence of D. rotundus roosts in epidemiological models, considering the scale and particularities of each region under study, the inclusion of other types of geological formation in addition to limestone for the formation of natural shelters, the inclusion of new types and land cover and the proximity of water bodies.

El murciélago vampiro Desmodus rotundus es el principal transmisor de la rabia herbívora, responsable de enormes pérdidas económicas en la ganadería en América Latina. Debido a las interacciones de D. rotundus con el medio ambiente, el riesgo de rabia en herbívoros puede explicarse por la vulnerabilidad y receptividad del medio ambiente a la capacidad del ecosistema para sustentar poblaciones de D. rotundus. Utilizando un Sistema de Información Geográfica, se analizaron cuantitativamente los siguientes determinantes de la receptividad en los que se encontraron los refugios de murciélagos vampiro D. rotundus en la ciudad de São Pedro SP: tipo de suelo y geología, uso y cobertura del suelo, pendiente, hipsometría y proximidad a cuerpos de agua. Se ubicaron ocho refugios de D.rotundus, siendo dos refugios naturales: una cueva de arenisca de Geología de la Formación Piramboia y Quartzarênico Neosol habitada por un solo murciélago, y otra cueva basáltica de Geología de la Formación Itaqueri y Latosol Rojo-amarillo con una población estimada de 100 D. rotundus. El 75% de los refugios estaban en áreas de pastos y caña de azúcar, seguidos de áreas de vegetación nativa y vegetación de ribera asociada a pastos. La presencia de refugios de D. rotundus en áreas cañeras y pastorales en mayor cantidad que en áreas de cobertura forestal resalta la importancia de ofrecer refugios artificiales en áreas agrícolas. La pendiente del terreno en el que se ubicaron los refugios osciló entre el 3% y el 29%. El 62,5% de los refugios se encontraban en zonas de baja pendiente con presencia de pastos, pero próximas a zonas de relieve más accidentado y vegetación autóctona con altitudes que oscilan entre 475 my 929 m. Todos los refugios estaban ubicados cerca de cuerpos de agua. Si bien los cuerpos de agua no aparecen como factor de receptividad a la presencia de refugios de D. rotundus en el modelo epidemiológico indicado por el Manual de Combate a la Rabia de Herbívoros - MAPA, en el presente estudio la proximidad de todos los refugios de D. rotundus to bodies d'agua destaca la importancia de este factor en la receptividad ambiental a la presencia de refugios para estos murciélagos, por lo que es relevante incluir este factor en los modelos epidemiológicos para el control de la rabia en herbívoros. Así, es necesario reevaluar la importancia de los factores de receptividad a la presencia de refugios de D. rotundus en los modelos epidemiológicos, considerando la escala y particularidades de cada región en estudio, la inclusión de otros tipos de formación geológica además de la caliza para la formación de refugios naturales, inclusión de nuevos tipos y coberturas terrestres y proximidad de cuerpos de agua.

Detection of Trypanosoma cruzi in the saliva of diverse neotropical bats.

Trypanosoma cruzi is widely reported in bats, yet transmission routes remain unclear. We present evidence from metagenomic sequence data that T. cruzi occurs in the saliva of diverse Neotropical bats. Phylogenetic analyses demonstrated that the bat-associated T. cruzi sequences described here formed part of a bat-specific clade, suggesting an independent transmission cycle. Our results highlight the value in repurposing metagenomic data generated for viral discovery to reveal insights into the biology of other parasites. Evaluating whether the presence of T. cruzi in the saliva of two hematophagous bat species represents an ecological route for zoonotic transmission of Chagas disease is an interesting avenue for future research.

Predictive risk model of livestock rabies occurrence in Peru / Modelo de risco preditivo para a ocorrência da raiva bovina no Peru

Livestock rabies is endemic in Peru. Hence, its persistence and annual dissemination represent an important economic impact, especially for impoverished farming communities. The disease is mostly transmitted by the hematophagous bat Desmodus rotundus. The present study aimed to adapt an existing predictive model of the occurrence of livestock rabies to Peru, in which the risk of rabies transmission from bats to livestock was estimated using decision-tree models of receptivity and vulnerability. Official rabies surveillance data between 2010 and 2015 were used along with possible risk factors, such as livestock biomass, environmental changes, and geomorphological characteristics. Several scenarios were established to evaluate the prediction of the occurrence of livestock rabies cases by determining more than one cut-off point of the receptivity variables. During the study period, the precision of the model was estimated through the sensitivity (39.46%) and specificity (98.64%) by using confusion matrices. Targeting control efforts, especially in districts with a high estimated risk, could represent the prevention of a significant proportion of livestock rabies cases, which would optimize the human and economic resources of the Peruvian surveillance service. However, the quality of data produced by the surveillance should be improved not only to obtain higher model precision but also to allow the adequate planning of control actions.(AU)

Raiva de herbívoros é endêmica no Peru. Consequentemente, sua disseminação persistente e anual representa um importante impacto econômico, especialmente às comunidades rurais empobrecidas. A doença é principalmente transmitida pelo morcego hematófago Desmodus rotundus. Este estudo tem por objetivo adaptar um modelo preditivo pré-existente às ocorrências de raiva de herbívoros no Peru, no qual o risco de transmissão de morcegos para os herbívoros foi estimado por meio de árvores de cenários de receptividade e vulnerabilidade. Foram usados os dados oficiais de vigilância da raiva entre 2010 e 2015, assim como os possíveis fatores de risco, tais quais a biomassa de animais, alterações ambientais e características geomorfológicas. Diversos cenários foram criados para avaliar a predição da ocorrência da raiva por meio da determinação de diversos pontos de corte das variáveis de receptividade. Durante o período de estudo, a precisão do modelo foi estimada por meio da sensibilidade (39,46%) e especificidade (98,64%), utilizando matrizes de confusão. Focando em esforços de controle, especialmente em distritos com elevado risco estimado, seria possível prevenir uma proporção significativa dos focos, o que poderia otimizar os recursos humanos e econômicos do serviço oficial peruano. Entretanto, a qualidade dos dados produzidos pelo sistema de vigilância deveria ser melhorada não somente para obter maior precisão do modelo, mas também para possibilitar o melhor planejamento das ações de controle desta doença.(AU)

A new locality record for Radfordiella desmodi radovsky, 1967 (Mesostigmata: Macronyssidae) parasitizing the vampire bat in Brazil

Macronyssid mites are ectoparasites of reptiles, birds, and mammals (mainly bats). Out of 35 genera in this family, Radfordiella Fonseca, 1948 is a genus from the Neotropical region with six valid species, found parasitizing phyllostomid bats. Only Radfordiella desmodi Radovsky, 1967 and Radfordiella oudemansi Fonseca, 1948 have been registered in Brazil. The present study provides a new locality record for the species R. desmodi, microscopy images to aid in the identification, and a distribution map.

Predictive risk model of livestock rabies occurrence in Peru / Modelo de risco preditivo para a ocorrência da raiva bovina no Peru

Livestock rabies is endemic in Peru. Hence, its persistence and annual dissemination represent an important economic impact, especially for impoverished farming communities. The disease is mostly transmitted by the hematophagous bat Desmodus rotundus. The present study aimed to adapt an existing predictive model of the occurrence of livestock rabies to Peru, in which the risk of rabies transmission from bats to livestock was estimated using decision-tree models of receptivity and vulnerability. Official rabies surveillance data between 2010 and 2015 were used along with possible risk factors, such as livestock biomass, environmental changes, and geomorphological characteristics. Several scenarios were established to evaluate the prediction of the occurrence of livestock rabies cases by determining more than one cut-off point of the receptivity variables. During the study period, the precision of the model was estimated through the sensitivity (39.46%) and specificity (98.64%) by using confusion matrices. Targeting control efforts, especially in districts with a high estimated risk, could represent the prevention of a significant proportion of livestock rabies cases, which would optimize the human and economic resources of the Peruvian surveillance service. However, the quality of data produced by the surveillance should be improved not only to obtain higher model precision but also to allow the adequate planning of control actions.(AU)

Raiva de herbívoros é endêmica no Peru. Consequentemente, sua disseminação persistente e anual representa um importante impacto econômico, especialmente às comunidades rurais empobrecidas. A doença é principalmente transmitida pelo morcego hematófago Desmodus rotundus. Este estudo tem por objetivo adaptar um modelo preditivo pré-existente às ocorrências de raiva de herbívoros no Peru, no qual o risco de transmissão de morcegos para os herbívoros foi estimado por meio de árvores de cenários de receptividade e vulnerabilidade. Foram usados os dados oficiais de vigilância da raiva entre 2010 e 2015, assim como os possíveis fatores de risco, tais quais a biomassa de animais, alterações ambientais e características geomorfológicas. Diversos cenários foram criados para avaliar a predição da ocorrência da raiva por meio da determinação de diversos pontos de corte das variáveis de receptividade. Durante o período de estudo, a precisão do modelo foi estimada por meio da sensibilidade (39,46%) e especificidade (98,64%), utilizando matrizes de confusão. Focando em esforços de controle, especialmente em distritos com elevado risco estimado, seria possível prevenir uma proporção significativa dos focos, o que poderia otimizar os recursos humanos e econômicos do serviço oficial peruano. Entretanto, a qualidade dos dados produzidos pelo sistema de vigilância deveria ser melhorada não somente para obter maior precisão do modelo, mas também para possibilitar o melhor planejamento das ações de controle desta doença.(AU)

Synergistic Effects of Grassland Fragmentation and Temperature on Bovine Rabies Emergence.

In 2007, common vampire bats were the source of the first outbreak of paralytic bovine rabies in Uruguay. The outbreak coincided in space and time with the fragmentation of native grasslands for monospecific forestry for wood and cellulose production. Using spatial analyses, we show that the increase in grassland fragmentation, together with the minimum temperature in the winter, accounts for the spatial pattern of outbreaks in the country. We propose that fragmentation may increase the connectivity of vampire bat colonies by promoting the sharing of feeding areas, while temperature modulates their home range plasticity. While a recent introduction of the virus from neighboring Brazil could have had an effect on outbreak occurrence, we show here that the distribution of rabies cases is unlikely to be explained by only an invasion process from Brazil. In accordance with previous modeling efforts, an increase in connectivity may promote spatial persistence of rabies virus within vampire bat populations. Our results suggest that land use planning might help to reduce grassland fragmentation and thus reduce risk of rabies transmission to livestock. This will be especially important in the context of climatic changes and increasing minimum temperatures in the winter.

Distribution pattern of ZO-1 and claudins in the epididymis of vampire bats.

Epithelial cells connect with each other by tight junctions (TJs) in several tissues. In epididymides, TJs proteins form the blood-epididymis barrier (BEB), which is crucial for male fertility. However, little is known about BEB morphological and physiological aspects in wild animals. This study examines the region-specific distribution pattern of TJs proteins in D. rotundus' epididymis, assessing their regulation in rainy and dry season. The expression of zonula occludens-1 (ZO-1), and claudins (Cldn)-1, -3, and -4 were evaluated by confocal immunofluorescence and ELISA analysis. Herein, ZO-1 was strictly expressed in TJs, whereas Cldns were expressed in TJs and basolateral membranes of epithelial cells. Their co-localization and intensity of expression varied in the epididymal regions examined. The effect of season on protein expression was detected mainly in TJ proteins located in the proximal regions. As such, in the initial segment (IS), Cldn-3 and -4 were detected at low levels in basolateral membranes in the rainy season compared to the dry season. Furthermore, in the distal IS, Cldn-1 expression was lower in TJs of epithelial cells during the rainy season than the dry season. ZO-1 expression was higher in the cauda region than the corpus region by ELISA analysis. Additionally, in the corpus region, ZO-1 expression was higher in TJs during dry season compared to the rainy season. Our study sheds light on the understanding of BEB in D. rotundus, improving the knowledge of their reproductive biology.

The common vampire bat Desmodus rotundus (Chiroptera: Phyllostomidae) and the transmission of the rabies virus to livestock: A contact network approach and recommendations for surveillance and control.

The importance of the common vampire bat Desmodus rotundus for the transmission of the rabies virus does not lie solely in its ability to transmit this disease to other mammals, but also in its capacity to adapt to environmental and climatic changes, granting them a wide geographical distribution. Control of this disease is currently based on culling of the vampire bat and vaccination of the livestock. A transmission model incorporating geographic and behavioral determinants of the vampire bat was proposed to direct and optimize the epidemiological surveillance and control of livestock rabies. This model was built using a bimodal network connecting 260 vampire bat roosts among themselves (roost-roost-network) and with 1557 farms (roost-farm network) in eastern Sao Paulo State, Brazil. These roosts were grouped in 9 communities, some very interconnected, and some not and the farms were grouped in 14 communities. From 2013 to 2017, 44 livestock rabies outbreaks occurred in the area, circulating among the farm communities during the entire period, with possible introductions from neighboring areas. Based on the network and environment parameters, it was possible to reasonably predict both the roosts' occupation type (harem, bachelor, overnight and empty) and livestock rabies outbreak occurrence. The network approach brings light to the importance of phylogenetic studies of bats and rabies virus. Finally, the understanding of the interactions between bats and their feeding sources, influenced by the environment, allows to establish more precise surveillance and control measures and, ultimately, with a lower cost-benefit ratio of these actions.

Demographic and environmental drivers of metagenomic viral diversity in vampire bats.

Viruses infect all forms of life and play critical roles as agents of disease, drivers of biochemical cycles and sources of genetic diversity for their hosts. Our understanding of viral diversity derives primarily from comparisons among host species, precluding insight into how intraspecific variation in host ecology affects viral communities or how predictable viral communities are across populations. Here we test spatial, demographic and environmental hypotheses explaining viral richness and community composition across populations of common vampire bats, which occur in diverse habitats of North, Central and South America. We demonstrate marked variation in viral communities that was not consistently predicted by a null model of declining community similarity with increasing spatial or genetic distances separating populations. We also find no evidence that larger bat colonies host greater viral diversity. Instead, viral diversity follows an elevational gradient, is enriched by juvenile-biased age structure, and declines with local anthropogenic food resources as measured by livestock density. Our results establish the value of linking the modern influx of metagenomic sequence data with comparative ecology, reveal that snapshot views of viral diversity are unlikely to be representative at the species level, and affirm existing ecological theories that link host ecology not only to single pathogen dynamics but also to viral communities.

Genetic diversity of Bartonella spp. in vampire bats from Brazil.

Recently, an increasing number of Bartonella species have been emerged to cause human diseases. Among animal reservoirs for Bartonella spp., bats stand out due to their high mobility, wide distribution, social behaviour and long-life span. Although studies on the role of vampire bats in the epidemiology of rabies have been extensively investigated in Latin America, information on the circulation and genetic diversity of Bartonella species in these bat species is scarce. In the present work, 208 vampire bats, namely Desmodus rotundus (the common vampire bat; n = 167), Diphylla ecaudata (the hairy-legged vampire bat; n = 32) and Diaemus youngii (the white-winged vampire bat; n = 9) from 15 different states in Brazil were sampled. DNA was extracted from liver tissue samples and submitted to real-time PCR (qPCR) and conventional PCR (cPCR) assays for Bartonella spp. targeting five genetic loci, followed by phylogenetic and genotype network analyses. Fifty-one out of 208 liver samples (24.51%) were positive for Bartonella DNA in the ITS real-time PCR assay [40 (78.43%) of them were from D. rotundus from 11 states, and 11 (21.57%) samples from D. ecaudata from three states. Eleven genotypes were found for each gltA and rpoB genes. Several ITS sequences detected in the present study clustered within the lineage that includes B. bacilliformis and B. ancachensis. The Bayesian phylogenetic inference based on the gltA gene positioned the obtained sequences in six different clades, closely related to Bartonella genotypes previously detected in D. rotundus and associated ectoparasites sampled in Latin America. On the other hand, the Bartonella rpoB genotypes clustered together with the ruminant species, B. schoenbuchensis and B. chomelii. The present study describes for the first time the molecular detection of Bartonella spp. in D. ecaudata bats. It also indicates that Bartonella spp. of vampire bats are genetically diverse and geographically widespread in Brazil.