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The hairy-legged vampire bat, Diphylla ecaudata, is a relatively rare, poorly known, and specialized species that feeds primarily on the blood of birds. We studied a large colony of D. ecaudata rosting with the common hematophagous bats Desmodus rotundus, in a brick house in São Paulo, a large metropolis in southeastern Brazil. The colony size varied from 68 individuals in July 2011 to 21 in February 2014, and females were slightly larger than males. This is the first record of a large group of D. ecaudata sheltering in a man-made structure in Brazil and the first largest group of the species recorded in the country. As a rabies control measure, some animals were subjected to fluorescent antibody and mouse inoculation tests. Blood samples were collected from 24 animals, and the sera were tested for the presence of rabies antibodies using a simplified fluorescent inhibition microtest. No bat tested positive for rabies. Using 0.5 IU/ml as the cut-off, the prevalence of rabies antibodies was 58.8% in D. ecaudata and 83.0% in D. rotundus. The expressive levels of rabies antibodies indicate that the rabies virus actively circulates between the two species. El murciélago vampiro patas peludas, Diphylla ecaudata, es una especie especializada, relativamente rara y poco conocida, que se alimenta principalmente de sangre de aves. Estudiamos una gran colonia de D. ecaudata cohabitando con el murciélago vampiro común Desmodus rotundus en una casa de ladrillos en la ciudad de São Paulo, una gran metrópolis en el sureste de Brasil. El tamaño de la colonia varió de 68 individuos en julio de 2011 a 21 en febrero de 2014, y las hembras fueron ligeramente más numerosas que los machos. Este es el primer registro de un grupo grande de D. ecaudata ocupando una estructura artificial en Brasil y el primer registro de un grupo tan grande de la especie en el país. Como medida de control de la rabia, algunos animales fueron sometidos a pruebas de anticuerpos fluorescentes y de inoculación utilizadas en ratones. Se recolectaron muestras de sangre de 24 animales y los sueros se analizaron para detectar la presencia de anticuerpos contra la rabia mediante una microprueba de inhibición fluorescente simplificada. Ningún murciélago dio positivo por rabia. Utilizando 0,5 UI/ml como punto de corte, la prevalencia de anticuerpos contra la rabia fue del 58,8% en D. ecaudata y del 83,0% en D. rotundus. Los niveles de expresión de anticuerpos contra la rabia indican que el virus de la rabia circula activamente entre las dos especies. [ABSTRACT FROM AUTHOR]

Abstract 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.

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. [ABSTRACT FROM AUTHOR]

In 2018, an outbreak of human rabies caused by the hematophagous bat Desmodus rotundus hit the Brazilian Amazon Basin community of Melgaço, Brazil, resulting in the death of 10 people, 9 of them children. The incidence of rabies has been on the rise among populations in conditions of vulnerability in this ecosystem due to human expansion into sylvatic environments and limited access to public health services. To address this issue, in September 2019, a collaborative effort from national, local, and international institutions promoted and executed a pilot for pre-exposure prophylaxis of a population in high-risk areas for hematophagous bat-mediated rabies. This measure is usually only implemented in response to outbreaks. The pilot was conducted in Portel, in a nearby location to the previous outbreak, with the use of fluvial transportation, and 2987 individuals in 411 dwellings were successfully vaccinated. It established a methodology for pre-exposure prophylaxis for populations in conditions of vulnerability, identifying logistics and costs, as well as characterizing the target riverine population regarding risk factors associated with bites by hematophagous bats. This approach offers a proactive measure to prevent future outbreaks and provides valuable insights into how to address the issue of rabies in remote and difficult-to-reach areas.

Bats carry many zoonotic pathogens without showing pronounced pathology, with a few exceptions. The underlying immune tolerance mechanisms in bats remain poorly understood, although information-rich omics tools hold promise for identifying a wide range of immune markers and their relationship with infection. To evaluate the generality of immune responses to infection, we assessed the differences and similarities in serum proteomes of wild vampire bats (Desmodus rotundus) across infection status with five taxonomically distinct pathogens: bacteria (Bartonella spp., hemoplasmas), protozoa (Trypanosoma cruzi), and DNA (herpesviruses) and RNA (alphacoronaviruses) viruses. From 19 bats sampled in 2019 in Belize, we evaluated the up- and downregulated immune responses of infected versus uninfected individuals for each pathogen. Using a high-quality genome annotation for vampire bats, we identified 586 serum proteins but found no evidence for differential abundance nor differences in composition between infected and uninfected bats. However, using receiver operating characteristic curves, we identified four to 48 candidate biomarkers of infection depending on the pathogen, including seven overlapping biomarkers (DSG2, PCBP1, MGAM, APOA4, DPEP1, GOT1, and IGFALS). Enrichment analysis of these proteins revealed that our viral pathogens, but not the bacteria or protozoa studied, were associated with upregulation of extracellular and cytoplasmatic secretory vesicles (indicative of viral replication) and downregulation of complement activation and coagulation cascades. Additionally, herpesvirus infection elicited a downregulation of leukocyte-mediated immunity and defense response but an upregulation of an inflammatory and humoral immune response. In contrast to our two viral infections, we found downregulation of lipid and cholesterol homeostasis and metabolism with Bartonella spp. infection, of platelet-dense and secretory granules with hemoplasma infection, and of blood coagulation pathways with T. cruzi infection. Despite the small sample size, our results suggest that vampire bats have a similar suite of immune mechanisms for viruses distinct from responses to the other pathogen taxa, and we identify potential biomarkers that can expand our understanding of pathogenesis of these infections in bats. By applying a proteomic approach to a multi-pathogen system in wild animals, our study provides a distinct framework that could be expanded across bat species to increase our understanding of how bats tolerate pathogens.

Simple Summary: Rabies is a fatal zoonotic disease and a significant cause of economic losses in cattle and equine farms located in South America. In this continent, it is primarily transmitted to these hosts through bites of the hematophagous bat Desmodus rotundus. This survey investigated the presence of rabies in cattle and equines in the state of Rondônia, situated in the Brazilian's Legal Amazon region, spanning from 2002 to 2021. The study correlated these findings with the preventive measures implemented by the local health agency (IDARON) for rabies management. Over this timeframe, there were 201 reported cases in cattle and 23 in horses. Both herbivores exhibited a declining trend in rabies incidences. No specific within-year patterns in rabies occurrence was identified, and there were variations in epidemic periods. The reduction in rabies incidence risk among cattle and horses was attributed to the ratio of treated bats and the sale of vaccines in the area while, on the other hand, the number of educational printed materials contributed to the increasing the incidence. Despite the diminishing trend of rabies in this Amazon Rainforest region, which can be attributed to the efforts of the animal health agency, the disease remains endemic, necessitating ongoing surveillance and prophylactic strategies for its control. 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. [ABSTRACT FROM AUTHOR]

The common vampire bat (Desmodus rotundus) maintains a diverse, sanguivorous diet, utilizing a broad range of prey taxa. As anthropogenic change alters the distribution of this species, shifts in predator–prey interactions are expected. Understanding prey richness and patterns of prey selection is, thus, increasingly informative from ecological, epidemiological, and economic perspectives. We reviewed D. rotundus diet and assessed the geographical, taxonomical, and behavioral features to find 63 vertebrate species within 21 orders and 45 families constitute prey, including suitable host species in regions of invasion outside D. rotundus' range. Rodentia contained the largest number of species utilized by D. rotundus, though cattle were the most commonly reported prey source, likely linked to the high availability of livestock and visibility of bite wounds compared to wildlife. Additionally, there was tendency to predate upon species with diurnal activity and social behavior, potentially facilitating convenient and nocturnal predation. Our review highlights the dietary heterogeneity of D. rotundus across its distribution. We define D. rotundus as a generalist predator, or parasite, depending on the ecological definition of its symbiont roles in an ecosystem (i.e., lethal vs. non-lethal blood consumption). In view of the eminent role of D. rotundus in rabies virus transmission and its range expansion, an understanding of its ecology would benefit public health, wildlife management, and agriculture. [ABSTRACT FROM AUTHOR]

Abstract Background The term virus ‘spillover’ embodies a highly complex phenomenon and is often used to refer to viral transmission from a primary reservoir host to a new, naïve yet susceptible and permissive host species. Spillover transmission can result in a virus becoming pathogenic, causing disease and death to the new host if successful infection and transmission takes place. Main text The scientific literature across diverse disciplines has used the terms virus spillover, spillover transmission, cross-species transmission, and host shift almost indistinctly to imply the complex process of establishment of a virus from an original host (source/donor) to a naïve host (recipient), which have close or distant taxonomic or evolutionary ties. Spillover transmission may result in unsuccessful onward transmission, if the virus dies off before propagation. Alternatively, successful viral establishment in the new host can occur if subsequent secondary transmission among individuals of the same novel species and among other sympatric susceptible species occurred. As such, virus spillover transmission is a common yet highly complex phenomenon that encompasses multiple subtle stages that can be deconstructed to be studied separately to better understand the drivers of disease emergence. Rabies virus (RABV) is a well-documented viral pathogen which still inflicts heavy impact on humans, companion animals, wildlife, and livestock throughout Latin America due substantial spatial temporal and ecological—natural and expansional—overlap with several virus reservoir hosts. Thereby, the rabies disease system represents a robust avenue through which the drivers and uncertainties surrounding spillover transmission can be unravel at its different subtle stages to better understand how they may be affected by coarse, medium, and fine scale variables. Conclusions The continued study of viral spillover transmission necessitates the elucidation of its complexities to better assess the cross-scale impacts of ecological forces linked to the propensity of spillover success. Improving capacities to reconstruct and predict spillover transmission would prevent public health impacts on those most at risk populations across the globe. Graphical Abstract:

Transmissible vaccines are an emerging biotechnology that hold prospects to eliminate pathogens from wildlife populations. Such vaccines would genetically modify naturally occurring, nonpathogenic viruses ("viral vectors") to express pathogen antigens while retaining their capacity to transmit. The epidemiology of candidate viral vectors within the target wildlife population has been notoriously challenging to resolve but underpins the selection of effective vectors prior to major investments in vaccine development. Here, we used spatiotemporally replicated deep sequencing to parameterize competing epidemiological mechanistic models of Desmodus rotundus betaherpesvirus (DrBHV), a proposed vector for a transmissible vaccine targeting vampire bat-transmitted rabies. Using 36 strain- and location-specific time series of prevalence collected over 6 y, we found that lifelong infections with cycles of latency and reactivation, combined with a high R0 (6.9; CI: 4.39 to 7.85), are necessary to explain patterns of DrBHV infection observed in wild bats. These epidemiological properties suggest that DrBHV may be suited to vector a lifelong, self-boosting, and transmissible vaccine. Simulations showed that inoculating a single bat with a DrBHV-vectored rabies vaccine could immunize >80% of a bat population, reducing the size, frequency, and duration of rabies outbreaks by 50 to 95%. Gradual loss of infectious vaccine from vaccinated individuals is expected but can be countered by inoculating larger but practically achievable proportions of bat populations. Parameterizing epidemiological models using accessible genomic data brings transmissible vaccines one step closer to implementation. [ABSTRACT FROM AUTHOR]

An especially interesting question is "How many species of bats can be found simultaneously in the same cave?" This information is surprisingly rare in the literature, mainly in the Neotropics. The aim of this study was to sample bats in Gruta do Limoeiro cave, Municipality of Castelo, State of Espírito Santo, Brazil after a 53-year interval of the first survey, by the naturalist Augusto Ruschi. Four surveys were conducted in 2005 and 2006, capturing bats with mist-nets and actively exploring the cave. We recorded eleven species of three families, Phyllostomidae, Vespertilionidae and Molossidae, making Gruta do Limoeiro cave one of the most diverse caves in the World for bats. Of the 14 species found by Ruschi, seven were still present, and four species were added. The seven species lost from Ruschi's list are mainly Emballonuridae and some Phyllostomidae, probably due to landscape changes. We recommend the long-term monitoring of the Gruta do Limoeiro cave to understand the loss in diversity, and consequently in ecosystem services. [ABSTRACT FROM AUTHOR]

Background: The term virus 'spillover' embodies a highly complex phenomenon and is often used to refer to viral transmission from a primary reservoir host to a new, naïve yet susceptible and permissive host species. Spillover transmission can result in a virus becoming pathogenic, causing disease and death to the new host if successful infection and transmission takes place. Main text: The scientific literature across diverse disciplines has used the terms virus spillover, spillover transmission, cross-species transmission, and host shift almost indistinctly to imply the complex process of establishment of a virus from an original host (source/donor) to a naïve host (recipient), which have close or distant taxonomic or evolutionary ties. Spillover transmission may result in unsuccessful onward transmission, if the virus dies off before propagation. Alternatively, successful viral establishment in the new host can occur if subsequent secondary transmission among individuals of the same novel species and among other sympatric susceptible species occurred. As such, virus spillover transmission is a common yet highly complex phenomenon that encompasses multiple subtle stages that can be deconstructed to be studied separately to better understand the drivers of disease emergence. Rabies virus (RABV) is a well-documented viral pathogen which still inflicts heavy impact on humans, companion animals, wildlife, and livestock throughout Latin America due substantial spatial temporal and ecological—natural and expansional—overlap with several virus reservoir hosts. Thereby, the rabies disease system represents a robust avenue through which the drivers and uncertainties surrounding spillover transmission can be unravel at its different subtle stages to better understand how they may be affected by coarse, medium, and fine scale variables. Conclusions: The continued study of viral spillover transmission necessitates the elucidation of its complexities to better assess the cross-scale impacts of ecological forces linked to the propensity of spillover success. Improving capacities to reconstruct and predict spillover transmission would prevent public health impacts on those most at risk populations across the globe. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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.

The pathogen transmission dynamics in bat reservoirs underpin efforts to reduce risks to human health and enhance bat conservation, but are notoriously challenging to resolve. For vampire bat rabies, the geographical scale of enzootic cycles, whether environmental factors modulate baseline risk, and how within-host processes affect population-level dynamics remain unresolved. We studied patterns of rabies exposure using an 11-year, spatially replicated sero-survey of 3709 Peruvian vampire bats and co-occurring outbreaks in livestock. Seroprevalence was correlated among nearby sites but fluctuated asynchronously at larger distances. A generalized additive mixed model confirmed spatially compartmentalized transmission cycles, but no effects of bat demography or environmental context on seroprevalence. Among 427 recaptured bats, we observed long-term survival following rabies exposure and antibody waning, supporting hypotheses that immunological mechanisms influence viral maintenance. Finally, seroprevalence in bats was only weakly correlated with outbreaks in livestock, reinforcing the challenge of spillover prediction even with extensive data. Together our results suggest that rabies maintenance requires transmission among multiple, nearby bat colonies which may be facilitated by waning of protective immunity. However, the likelihood of incursions and dynamics of transmission within bat colonies appear largely independent of bat ecology. The implications of these results for spillover anticipation and controlling transmission at the source are discussed. [ABSTRACT FROM AUTHOR]

In 2018, an outbreak of human rabies caused by the hematophagous bat Desmodus rotundus hit the Brazilian Amazon Basin community of Melgaço, Brazil, resulting in the death of 10 people, 9 of them children. The incidence of rabies has been on the rise among populations in conditions of vulnerability in this ecosystem due to human expansion into sylvatic environments and limited access to public health services. To address this issue, in September 2019, a collaborative effort from national, local, and international institutions promoted and executed a pilot for pre-exposure prophylaxis of a population in high-risk areas for hematophagous bat-mediated rabies. This measure is usually only implemented in response to outbreaks. The pilot was conducted in Portel, in a nearby location to the previous outbreak, with the use of fluvial transportation, and 2987 individuals in 411 dwellings were successfully vaccinated. It established a methodology for pre-exposure prophylaxis for populations in conditions of vulnerability, identifying logistics and costs, as well as characterizing the target riverine population regarding risk factors associated with bites by hematophagous bats. This approach offers a proactive measure to prevent future outbreaks and provides valuable insights into how to address the issue of rabies in remote and difficult-to-reach areas.

The apparent ability of bats to harbor many virulent viruses without showing disease is likely driven by distinct immune responses that coevolved with mammalian flight and the exceptional longevity of this order. Yet our understanding of the immune mechanisms of viral tolerance is restricted to a small number of bat-virus relationships and remains poor for coronaviruses (CoVs), despite their relevance to human health. Proteomics holds particular promise for illuminating the immune factors involved in bat responses to infection, because it can accommodate especially low sample volumes (e.g., sera) and thus can be applied to both large and small bat species as well as in longitudinal studies where lethal sampling is necessarily limited. Further, as the serum proteome includes proteins secreted from not only blood cells but also proximal organs, it provides a more general characterization of immune proteins. Here, we expand our recent work on the serum proteome of wild vampire bats (Desmodus rotundus) to better understand CoV pathogenesis. Across 19 bats sampled in 2019 in northern Belize with available sera, we detected CoVs in oral or rectal swabs from four individuals (21.1% positivity). Phylogenetic analyses identified all RdRp gene sequences in vampire bats as novel a-CoVs most closely related to known human CoVs. Across 586 identified serum proteins, we found no strong differences in protein composition nor abundance between uninfected and infected bats. However, receiver operating characteristic curve analyses identified seven to 32 candidate biomarkers of CoV infection, including AHSG, C4A, F12, GPI, DSG2, GSTO1, and RNH1. Enrichment analyses using these protein classifiers identified downregulation of complement, regulation of proteolysis, immune effector processes, and humoral immunity in CoV-infected bats alongside upregulation of neutrophil immunity, overall granulocyte activation, myeloid cell responses, and glutathione processes. Such results denote a mostly cellular immune response of vampire bats to CoV infection and identify putative biomarkers that could provide new insights into CoV pathogenesis in wild and experimental populations. More broadly, applying a similar proteomic approach across diverse bat species and to distinct life history stages in target species could improve our understanding of the immune mechanisms by which wild bats tolerate viruses. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Bat assemblages and breeding biology remain relatively poorly studied in northern Central America, especially in Honduras, which limits our abilities to make informed decisions regarding bat conservation. Here we provide information on species composition, sex ratio, and reproduction of a bat assemblage from an area relatively unstudied. During 43 nights of fieldwork, we studied an understory bat assemblage in the highlands of central Honduras for an annual cycle. We captured 594 individuals from 22 species representing two families--Phyllostomidae and Vespertilionidae--using mist nets located near ground level. Our captures include two species that are of global conservation concern and are considered rare in Honduras--Leptonycteris yerbabuenae and Choeronycteris mexicana. We estimate species richness of the Phyllostomidae to be 19 species in this fragmented landscape. In this family, we found nectarivorous species to breed earlier in the year, at the end of the dry season into the wet season, a result reported from other Neotropical areas characterized by pronounced wet and dry seasons. Sex equity was found for most species, except Desmodus rotundus, Sturnira parvidens, and Anoura geoffroyi. Compared to other studies from similar habitat and under similar effort, our results suggest that Honduran highlands host high phyllostomid bat biodiversity, including species of conservation interest, despite habitat fragmentation and anthropogenic land use. [ABSTRACT FROM AUTHOR]

A raiva é uma enfermidade viral que acomete animais silvestres e domésticos relatada no Brasil desde 1911. Sob o ponto de vista de saúde pública é imperativo que pessoas que tenham contato com animais sejam submetidas a vacinação. O vírus da raiva é neurotrópico e altamente letal a humanos e animais. Os prejuízos inerentes a raiva são de difícil quantificação e a cadeia produtiva de bovinos é a mais afetada. O presente trabalho aborda de maneira sucinta aspectos etiológicos da raiva, bem como fatores epidemiológicos envolvidos na manutenção da enfermidade em sistemas produtivos e, no meio silvestre e urbano. Os sinais clínicos em animais acometidos pela enfermidade foram elencados conforme as espécies e formas clínicas de apresentação da raiva, a saber, paralítica e furiosa. Também foram abordados tópicos sobre as principais alterações de necropsia, lesões histopatológicas da enfermidade com algumas peculiaridades referentes a distribuição e características das lesões. Foram listadas as principais formas de diagnóstico da raiva em animais de produção e medidas de controle e profilaxia.

The apparent ability of bats to harbor many virulent viruses without showing disease is likely driven by distinct immune responses that coevolved with mammalian flight and the exceptional longevity of this order. Yet our understanding of the immune mechanisms of viral tolerance is restricted to a small number of bat–virus relationships and remains poor for coronaviruses (CoVs), despite their relevance to human health. Proteomics holds particular promise for illuminating the immune factors involved in bat responses to infection, because it can accommodate especially low sample volumes (e.g., sera) and thus can be applied to both large and small bat species as well as in longitudinal studies where lethal sampling is necessarily limited. Further, as the serum proteome includes proteins secreted from not only blood cells but also proximal organs, it provides a more general characterization of immune proteins. Here, we expand our recent work on the serum proteome of wild vampire bats (Desmodus rotundus) to better understand CoV pathogenesis. Across 19 bats sampled in 2019 in northern Belize with available sera, we detected CoVs in oral or rectal swabs from four individuals (21.1% positivity). Phylogenetic analyses identified all RdRp gene sequences in vampire bats as novel α-CoVs most closely related to known human CoVs. Across 586 identified serum proteins, we found no strong differences in protein composition nor abundance between uninfected and infected bats. However, receiver operating characteristic curve analyses identified seven to 32 candidate biomarkers of CoV infection, including AHSG, C4A, F12, GPI, DSG2, GSTO1, and RNH1. Enrichment analyses using these protein classifiers identified downregulation of complement, regulation of proteolysis, immune effector processes, and humoral immunity in CoV-infected bats alongside upregulation of neutrophil immunity, overall granulocyte activation, myeloid cell responses, and glutathione processes. Such results denote a mostly cellular immune response of vampire bats to CoV infection and identify putative biomarkers that could provide new insights into CoV pathogenesis in wild and experimental populations. More broadly, applying a similar proteomic approach across diverse bat species and to distinct life history stages in target species could improve our understanding of the immune mechanisms by which wild bats tolerate viruses.

Rabies is considered a re-emerging disease due to increased contact with the reservoir. The vampire bat Desmodus rotundus is the reservoir and main transmitter of this disease. Alterations in the natural environment have caused imbalances of impact on the ecology, influencing the movement of the reservoir from natural areas to rural and urban environments, where there are human settlements and the presence of domestic animals. The objective of this work has been to present the most relevant aspects about the role of the vampire bat as a natural reservoir and main transmitter of rabies in the region in order to raise awareness in the population about the risk this is to public health. Attacks by vampire bat Desmodus rotundus on livestock species are becoming more frequent, even in regions that for decades had been considered free from rabies. This represents a public health problem, because these cases can generate contacts between infected animals and people.

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.

Introduction: The sylvatic cycle of rabies is a significant sanitary burden in Central America. The Costa Rican government monitors cases since 1985 and infections from bats are still reported for wild animals, livestock, and humans, generating a need of further pathogen characterization in the region. Objective: To compare rabies phylogenetic analyses from complete genomes with nucleoprotein gene studies. Methods: For the phylogenetic analyses we used four rabies tissue samples collected in 2018, and generated complete genomes by Next-Generation sequencing (NGS). We also extracted RNA from tissues of confirmed cases and generated ssDNA using several primers. Double-stranded DNA was generated and used to generate genomic libraries. Results: We describe, for the first-time, the complete genome of four sequences of the rabies virus isolated in Costa Rica in 2018. Complete genome trees resembled the topology of nucleoprotein gene trees. All isolates were related to Desmodus rotundus. One sample group into Lineage (L)2, and the remaining samples group in L1, matched previous reports from regional rabies viruses. Conclusion: Our method produces valid viral assemblies from clinical specimens without target enrichment or viral isolation.

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.

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.

Cattle ranching is one of the main production activities in the Neotropics that has unavoidably led to cattle exposure to the common vampire bat (Desmodus rotundus) and rabies virus. Although many studies have assessed this issue, the influence of environmental characteristics associated with land use and social and production constraints have received little attention. We used satellite imagery classification to identify a gradient of landscape disturbance and analyzed the effects of cattle management and landscape structure on common vampire bat abundance and feeding prevalence. Evidence of the common vampire bat feeding on cattle was common in the study area: 87.5% of the ranchers interviewed claimed to have experienced this problem. The abundance and feeding prevalence of the common vampire bat was lower in landscapes dominated by open fields, scarce forest cover, and agricultural land. Bat abundance was positively associated with the presence of streams in the proximity of grazing areas, whereas cave's presence was associated with higher feeding prevalence. We suggest that cattle grazing should avoid the proximity of streams, caves, and forests as much as possible, as these conditions increase the exposure of cattle to the common vampire bat and the potential for feeding, which can increase the likelihood of rabies virus transmission. [ABSTRACT FROM AUTHOR]

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.

Serology is a core component of the surveillance and management of viral zoonoses. Virus neutralization tests are a gold standard serological diagnostic, but requirements for large volumes of serum and high biosafety containment can limit widespread use. Here, focusing on Rabies lyssavirus, a globally important zoonosis, we developed a pseudotype micro‐neutralization rapid fluorescent focus inhibition test (pmRFFIT) that overcomes these limitations. Specifically, we adapted an existing micro‐neutralization test to use a green fluorescent protein‐tagged murine leukaemia virus pseudotype in lieu of pathogenic rabies virus, reducing the need for specialized reagents for antigen detection and enabling use in low‐containment laboratories. We further used statistical models to generate rapid, quantitative predictions of the probability and titre of rabies virus‐neutralizing antibodies from microscopic imaging of neutralization outcomes. Using 47 serum samples from domestic dogs with neutralizing antibody titres estimated using the fluorescent antibody virus neutralization test (FAVN), pmRFFIT showed moderate sensitivity (78.79%) and high specificity (84.62%). Despite small conflicts, titre predictions were correlated across tests repeated on different dates both for dog samples (r = 0.93) and in a second data set of sera from wild common vampire bats (r = 0.72, N = 41), indicating repeatability. Our test uses a starting volume of 3.5 µl of serum, estimates titres from a single dilution of serum rather than requiring multiple dilutions and end point titration, and may be adapted to target neutralizing antibodies against alternative lyssavirus species. The pmRFFIT enables high‐throughput detection of rabies virus‐neutralizing antibodies in low‐biocontainment settings and is suited to studies in wild or captive animals where large serum volumes cannot be obtained. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract Host ecological factors and external environmental factors are known to influence the structure of gut microbial communities, but few studies have examined the impacts of environmental changes on microbiotas in free‐ranging animals. Rapid land‐use change has the potential to shift gut microbial communities in wildlife through exposure to novel bacteria and/or by changing the availability or quality of local food resources. The consequences of such changes to host health and fitness remain unknown and may have important implications for pathogen spillover between humans and wildlife. To better understand the consequences of land‐use change on wildlife microbiotas, we analyzed long‐term dietary trends, gut microbiota composition, and innate immune function in common vampire bats (Desmodus rotundus) in two nearby sites in Belize that vary in landscape structure. We found that vampire bats living in a small forest fragment had more homogenous diets indicative of feeding on livestock and shifts in microbiota heterogeneity, but not overall composition, compared to those living in an intact forest reserve. We also found that irrespective of sampling site, vampire bats which consumed relatively more livestock showed shifts in some core bacteria compared with vampire bats which consumed relatively less livestock. The relative abundance of some core microbiota members was associated with innate immune function, suggesting that future research should consider the role of the host microbiota in immune defense and its relationship to zoonotic infection dynamics. We suggest that subsequent homogenization of diet and habitat loss through livestock rearing in the Neotropics may lead to disruption to the microbiota that could have downstream impacts on host immunity and cross‐species pathogen transmission.

The rabies virus propagates through several epidemiological cycles, which makes it difficult to control and predict. Thus, this study was structured with the aim of establishing the geospatial characterization of bat shelters in different semi-arid mesoregions of the state of Paraíba, Northeastern region of Brazil. Data provided by the Secretaria de Estado do Desenvolvimento da Agropecuária e da Pesca da Paraíba (SEDAP-PB), from 2007 to 2015 and data from digital platforms were used. The geographic representation was produced using the software QGIS 2.16.0 - Nodebo. To verify virus circulation sites, buffers were plotted within a 10-km radius from the registered shelters and rabies incidence sites in the state. A registry of 93 shelters in the period between 2007 and 2015 were distributed in 22 municipalities and 15 microregions. All mesoregions were represented, though 47.31% of the bat shelters were located in Agreste Paraibano. Of the total registered shelters, 66 (71%) are classified as artificial, and 27 (29%) as natural. The underreporting of rabies occurrences reveals the need to improve the registration of hematophagous bat shelters, specifically those for the D. rotundus species.

In the Neotropics, vampire bats (Desmodus rotundus) are the main reservoir host for rabies, a highly fatal encephalitis caused by viruses in the genus Lyssavirus. Although patterns of rabies virus exposure and infection have been well studied for vampire bats in South America and Mexico, exploring the ecology of vampire bat rabies in other regions is crucial for predicting risks to livestock and humans. In Belize, rabies outbreaks in livestock have increased in recent years, underscoring the need for systematic data on viral dynamics in vampire bats. In this study, we examine the first three years of a longitudinal study on the ecology of vampire bat rabies in northern Belize. Rabies seroprevalence in bats was high across years (29%–80%), suggesting active and endemic virus circulation. Across two locations, the seroprevalence time series per site were inversely related and out of phase by at least a year. Microsatellite data demonstrated historic panmixia of vampire bats, and mark–recapture detected rare but contemporary inter‐site dispersal. This degree of movement could facilitate spatial spread of rabies virus but is likely insufficient to synchronize infection dynamics, which offers one explanation for the observed phase lag in seroprevalence. More broadly, our analyses suggest frequent transmission of rabies virus within and among vampire bat roosts in northern Belize and highlight the need for future spatiotemporal, phylogenetic and ecological studies of vampire bat rabies in Central America. [ABSTRACT FROM AUTHOR]

Durante o ano de 2002, foi realizada uma busca por abrigos de morcegos hematófagos Desmodus rotundus no município de São Pedro - SP. Quando localizados, essas populações foram georeferenciadas e avaliadas quanto a sua população e utilização. Esses dados foram fornecidos à Coordenadoria de Defesa Agropecuária, a qual enviou uma equipe técnica no dia 08/05/2002 para a realização de um controle populacional através da aplicação de pasta vampiricida. Para a avaliação da repopulação dos abrigos, foram realizadas inspeções nos dias 10/09/2002, 12/04/2005 e 11/05/2006. A repopulação de abrigos foi reduzida de 62,5 % a 87,5%. Quando houve, essa repopulação se deu, principalmente, pela presença de machos em grutas e um túnel. Também foram enviadas amostras de D. rotundus para o Instituto Pasteur - SP, para pesquisa do antígeno rábico e prova biológica, sendo que todas apresentaram resultados negativos. A ausência de repopulação de abrigos por fêmeas e formação de novas maternidades por um período de quatro anos é um indício de que a população de D. rotundus está controlada, não ocorrendo crescimento vegetativo da população destes morcegos nesta região. O monitoramento da repopulação dos abrigos por D. rotundus, bem como o envio de amostras para pesquisa do antígeno rábico nessa população são importantes ferramentas de estudos de corte epidemiológico do vírus da raiva, além de possibilitar o aprimoramento de estratégias no controle seletivo desses morcegos e da raiva dos herbívoros.

Bats (Chiroptera) are often viewed negatively by the public. Negative public perceptions of bats may hinder efforts to conserve declining populations. In Belize, the presence of vampire bats (Desmodus rotundus and Diphylla ecaudata) exacerbates the potential for conflicts with humans because of the increased rabies transmission risks. To mitigate these risks, the Belize government provides farmers with assistance to trap and remove vampire bats. In June 2018, we surveyed farmers (n = 44) in and adjacent to the Vaca Forest Reserve in Belize to learn more about their attitudes, knowledge, and experiences with bats. This information may provide new insights and approaches to address farmers’ concerns and enhance bat conservation efforts in Belize. Farmers held negative attitudes toward bats, exhibited low knowledge of their ecosystem services, and supported the trapping and use of toxicants to control bat populations to reduce the risk of rabies transmission between vampire bats and livestock. Farmers with livestock had more negative attitudes toward bats than farmers without livestock. Despite farmers reporting depredation incidences with fruit-eating and vampire bats, farmers expressed more negative attitudes toward vampire bats. We recommend that conservation education efforts target all stakeholders in the reserve to increase awareness about the importance of bats to ecosystems and highlight the dangers of indiscriminate trapping. Cumulatively, this may lead to positive attitude changes toward bats and their conservation.

Spatial epidemiology of bat-transmitted rabies in cattle has been limited to spatial distribution of cases, an approach that does not identify hidden patterns and the spread resulting in outbreaks in endemic and susceptible areas. Therefore, the purpose of this study was to determine the relationship between the three variables average annual maximum, annual minimum temperature and precipitation in the region on the one hand, and the spatial distribution of cases on the other, using geographic information systems and co-Kriging considering that these environmental variables condition the existence of the rabies vector Desmodus rotundus. A stationary behaviour between the primary and the secondary variables was verified by basic statistics and moving window statistics. The directions of greater and lesser spatial continuity were determined by experimental cross-semivariograms. It was found that the highest risk for bovine paralytic rabies occurs in areas known as La Huasteca Potosina and La Sierra Gorda that are characterized by a maximum temperature of 29.5 °C, a minimum temperature of 16.5 °C and precipitation of 1200 mm. A risk estimation map was obtained for the presence of rabies with a determination coefficient greater than 95%, and a correlation coefficient greater than 0.95. Our conclusion is that ordinary co- Kriging provides a better estimation of risk and spatial distribution of rabies than simple Kriging, making this the method recommended for risk estimation and regional distribution of rabies.

The aim of this research was to detect rabies virus in peripheral tissues in captive vampires. Vampire bats were inoculated with 106 MICLD50 of homologous rabies virus. Bats displayed clinical signs of rabies beginning on d 8 until the 19th d post-inoculation (pi). Rabies virus antigens were found in the brain of all rabid bats. Viral RNA was detected in brain, salivary gland and tongue tissue by RT-PCR and nested PCR (nPCR). Viral genome was also detected in organs unrelated to the central nervous system. Rabies virus was not detected in saliva nor documented from any tissues without occurrence of viral antigens in the brain. Host humoral response was most pronounced via the induction of viral neutralizing antibodies (VNA) from d 8 to 20 pi, having a peak at d 14 with 0.9 IU. Antibody levels were variable, but tended to remain high after inoculation, showing significant differences to the negative control group (P=0.001). This research is one of the few recent studies focused upon Desmodus rotundus and contributes to the basic knowledge of rabies virus pathogenesis, which is required for an understanding of perpetuation in a major viral reservoir in Latin America.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Bats (Chiroptera) are often viewed negatively by the public. Negative public perceptions of bats may hinder efforts to conserve declining populations. In Belize, the presence of vampire bats (Desmodus rotundus and Diphylla ecaudata) exacerbates the potential for conflicts with humans because of the increased rabies transmission risks. To mitigate these risks, the Belize government provides farmers with assistance to trap and remove vampire bats. In June 2018, we surveyed farmers (n = 44) in and adjacent to the Vaca Forest Reserve in Belize to learn more about their attitudes, knowledge, and experiences with bats. This information may provide new insights and approaches to address farmers' concerns and enhance bat conservation efforts in Belize. Farmers held negative attitudes toward bats, exhibited low knowledge of their ecosystem services, and supported the trapping and use of toxicants to control bat populations to reduce the risk of rabies transmission between vampire bats and livestock. Farmers with livestock had more negative attitudes toward bats than farmers without livestock. Despite farmers reporting depredation incidences with fruit-eating and vampire bats, farmers expressed more negative attitudes toward vampire bats. We recommend that conservation education efforts target all stakeholders in the reserve to increase awareness about the importance of bats to ecosystems and highlight the dangers of indiscriminate trapping. Cumulatively, this may lead to positive attitude changes toward bats and their conservation. [ABSTRACT FROM AUTHOR]

The vampire bat (Desmodus rotundus) plays a crucial role in the maintenance and transmission of the rabies virus to humans and livestock, impacting public health and economic production. Its importance lies not only in its capacity to transmit the virus but also in its ability to adapt to anthropic changes, as expressed in its wide geographic distribution in Latin America. Deforestation, livestock intensification, and other human activities have reduced the abundance of its wild prey but have also provided new and abundant shelter and foraging resources for the vampire bats. We used radiotelemetry to evaluate relations between topography, feeding site choice, and foraging behavior in southeastern Brazil, where three occupied D. rotundus roosts, out of 11 possible, were systematically monitored throughout a 1-year period once every 2 months. Sixty-two vampire bats were captured; biometric data were collected and 44 radiotransmitters were installed in adult individuals, producing telemetry data that were recorded in VHF receptors installed in the farms. Elevation of the roosts was related to the farms attacked by the vampire bats. Understanding the use of the environment and resources by vampire bats is critical to improving rabies control aiming at the reduction of disease impacts. From the perspective of the official veterinary service, telemetry would be ineffective as a rabies surveillance system due to the costs and limitations of the available technology. However, livestock rabies control measures would be greatly improved if ecological characteristics of the vampire bat were considered. [ABSTRACT FROM AUTHOR]

The vampire bat (Desmodus rotundus) plays a crucial role in the maintenance and transmission of the rabies virus to humans and livestock, impacting public health and economic production. Its importance lies not only in its capacity to transmit the virus but also in its ability to adapt to anthropic changes, as expressed in its wide geographic distribution in Latin America. Deforestation, livestock intensification, and other human activities have reduced the abundance of its wild prey but have also provided new and abundant shelter and foraging resources for the vampire bats. We used radiotelemetry to evaluate relations between topography, feeding site choice, and foraging behavior in southeastern Brazil, where three occupied D. rotundus roosts, out of 11 possible, were systematically monitored throughout a 1-year period once every 2 months. Sixty-two vampire bats were captured; biometric data were collected and 44 radiotransmitters were installed in adult individuals, producing telemetry data that were recorded in VHF receptors installed in the farms. Elevation of the roosts was related to the farms attacked by the vampire bats. Understanding the use of the environment and resources by vampire bats is critical to improving rabies control aiming at the reduction of disease impacts. From the perspective of the official veterinary service, telemetry would be ineffective as a rabies surveillance system due to the costs and limitations of the available technology. However, livestock rabies control measures would be greatly improved if ecological characteristics of the vampire bat were considered. [ABSTRACT FROM AUTHOR]

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. see also the Perspective by Wille [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Rabies is listed as one of the World Health Organisation’s (WHO) Neglected Tropical Diseases Worldwide, with a significant impact in South America. This paper explores the dynamics of rabies cases in humans, pets (dogs and cats), livestock and wildlife (bats in particular) in South America during the period 2009–2018. The data used in this study were derived from the two main databases for rabies in South America: the OIE-WAHIS from the World Organisation for Animal Health (OIE) and PANAFTOSA’s Regional Information System for the Epidemiological Surveillance of Rabies (SIRVERA). Being a neglected disease with possible underreporting in some areas, the reported rabies cases may not always represent the real disease burden. The analysis focuses on the evolution of the number of cases in time and their spatial distribution, as well as on the main source of infections in humans, determined by laboratory assays of the antigenic variant or through epidemiological investigations. Additionally, Generalised Linear Mixed Models (GLMM) were used to evaluate the risk factors associated with the occurrence of human cases. Our results show that the highest impact of the disease in terms of number of cases was reported on livestock, while the overall number of cases (in animals and humans) progressively decreased along the study period. The spatial distribution of rabies in livestock showed two main clusters in the north-western (mainly Colombia) and in the south-eastern part of the affected area (Brazil), and a third smaller cluster in Peru. A cluster in dogs was observed in Bolivia. Out of the 192 human cases reported during the study period, 70% of them were transmitted by bats. The number of human cases reported during the study period were significantly associated with the number of rabies cases reported in livestock, pets and wildlife. Despite the overall decreasing case report rate, the disease still represents a major animal and public health concern in South America, and new strategies for compiling systematic information, networking and education are needed, as well as the education and training of veterinary staff.

Rabies is a zoonosis of great importance for human and animal health, being responsible for a progressive and acute encephalitis in humans and animals. Considering that the correct viral identification has serious implications for the prophylaxis and treatment, is important a diagnostic system specifically designed for monitoring the infection cases. The objective of the study was to describe the occurrence of rabies in hematophagous bats (Desmodus rotundus) analyzing many diagnoses performed in the state of Sergipe. The objective of this study was to describe the occurrence of rabies in hematophagous bats (Desmodus rotundus) from an analysis of the diagnoses performed in the state of Sergipe. An observational, descriptive and retrospective study was conducted with the evaluation of 935 rabies diagnoses in bats (D. rotundus) between 1987 and 2014. It was noticed that only one case was positive in the city of Aracaju in the year 2000 and no positive bat was identified with the rabies virus in the rural area. The results show the need to increase the monitoring of rabies in other species of non-hematophagous bats, and especially in other wild reservoirs. It is suggested that the monitoring of rabies take into account the specific ecosystem of each region, since Brazil has continental dimensions and a great biological diversity.

Bats carry many zoonotic pathogens without showing pronounced pathology, with a few exceptions. The underlying immune tolerance mechanisms in bats remain poorly understood, although information-rich omics tools hold promise for identifying a wide range of immune markers and their relationship with infection. To evaluate the generality of immune responses to infection, we assessed the differences and similarities in serum proteomes of wild vampire bats ( Desmodus rotundus ) across infection status with five taxonomically distinct pathogens: bacteria ( Bartonella spp., hemoplasmas), protozoa ( Trypanosoma cruzi ), and DNA (herpesviruses) and RNA (alphacoronaviruses) viruses. From 19 bats sampled in 2019 in Belize, we evaluated the up- and downregulated immune responses of infected versus uninfected individuals for each pathogen. Using a high-quality genome annotation for vampire bats, we identified 586 serum proteins but found no evidence for differential abundance nor differences in composition between infected and uninfected bats. However, using receiver operating characteristic curves, we identified four to 48 candidate biomarkers of infection depending on the pathogen, including seven overlapping biomarkers (DSG2, PCBP1, MGAM, APOA4, DPEP1, GOT1, and IGFALS). Enrichment analysis of these proteins revealed that our viral pathogens, but not the bacteria or protozoa studied, were associated with upregulation of extracellular and cytoplasmatic secretory vesicles (indicative of viral replication) and downregulation of complement activation and coagulation cascades. Additionally, herpesvirus infection elicited a downregulation of leukocyte-mediated immunity and defense response but an upregulation of an inflammatory and humoral immune response. In contrast to our two viral infections, we found downregulation of lipid and cholesterol homeostasis and metabolism with Bartonella spp. infection, of platelet-dense and secretory granules with hemoplasma infection, and of blood coagulation pathways with T. cruzi infection. Despite the small sample size, our results suggest that vampire bats have a similar suite of immune mechanisms for viruses distinct from responses to the other pathogen taxa, and we identify potential biomarkers that can expand our understanding of pathogenesis of these infections in bats. By applying a proteomic approach to a multi-pathogen system in wild animals, our study provides a distinct framework that could be expanded across bat species to increase our understanding of how bats tolerate pathogens., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Vicente-Santos, Lock, Allira, Dyer, Dunsmore, Tu, Volokhov, Herrera, Lei, Relich, Janech, Bland, Simmons and Becker.)

O vírus rábico se propaga por vários ciclos epidemiológicos dificultando seu controle e previsibilidade de ocorrência. Desta forma, o objetivo desse estudo foi realizar a caracterização geoespacial dos abrigos de morcegos nas diferentes mesorregiões do semiárido paraibano, região Nordeste do Brasil. Foram utilizados dados fornecidos pela Secretaria de Estado do Desenvolvimento da Agropecuária e da Pesca da Paraíba (SEDAP-PB), do período entre 2007 à 2015 e dados de plataformas digitais. A representação geográfica foi produzida por meio do software QGIS 2.16.0 - Nodebo. Foram plotados buffers com raio de 10 km dos abrigos cadastrados e das ocorrências de raiva no Estado para verificar os possíveis locais de circulação do vírus, com o cadastro de 93 abrigos no período entre 2007 e 2015. Foram amostrados abrigos distribuídos em 22 municípios, 15 microrregiões e representados em todas as mesorregiões, em destaque a do Agreste Paraibano concentrando 47,31% do total de abrigos do morcego Desmodus rotundus. Do total de abrigos cadastrados 66 (71%) estão classificados como artificiais e 27 (29%) como naturais. As subnotificações das ocorrências de raiva na Paraíba revelam à necessidade de aumentar o trabalho de cadastramento de abrigos de morcegos hematófagos, com ênfase para a espécie Desmodus rotundus.

Host ecological factors and external environmental factors are known to influence the structure of gut microbial communities, but few studies have examined the impacts of environmental changes on microbiotas in free‐ranging animals. Rapid land‐use change has the potential to shift gut microbial communities in wildlife through exposure to novel bacteria and/or by changing the availability or quality of local food resources. The consequences of such changes to host health and fitness remain unknown and may have important implications for pathogen spillover between humans and wildlife. To better understand the consequences of land‐use change on wildlife microbiotas, we analyzed long‐term dietary trends, gut microbiota composition, and innate immune function in common vampire bats (Desmodus rotundus) in two nearby sites in Belize that vary in landscape structure. We found that vampire bats living in a small forest fragment had more homogenous diets indicative of feeding on livestock and shifts in microbiota heterogeneity, but not overall composition, compared to those living in an intact forest reserve. We also found that irrespective of sampling site, vampire bats which consumed relatively more livestock showed shifts in some core bacteria compared with vampire bats which consumed relatively less livestock. The relative abundance of some core microbiota members was associated with innate immune function, suggesting that future research should consider the role of the host microbiota in immune defense and its relationship to zoonotic infection dynamics. We suggest that subsequent homogenization of diet and habitat loss through livestock rearing in the Neotropics may lead to disruption to the microbiota that could have downstream impacts on host immunity and cross‐species pathogen transmission. [ABSTRACT FROM AUTHOR]