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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 apparently is expanding its range northwards in Mexico and seems poised to enter the southern United States. Climate models predict suitable habitat in the U.S. in south Texas and parts of southern Arizona. While vampire bats’ northward range expansion is not unexpected, the fact that this species brings a strain of rabies that impacts livestock and people warrants a strategic response. Annual economic damages from bats are estimated between $7M and $9M, largely associated with deaths of livestock from rabies. To prepare for the emerging rabies issue, USDA Wildlife Services programs in Texas and Arizona have begun training employees to recognize symptoms and respond to bat presence. Surveillance of livestock at sale barns and on ranches is designed to maximize the opportunity to detect bat bites in livestock. Outreach on the issue, via one-on-one training and a DVD handout to landowners along both sides of the border, has been initiated. This paper details the extent of preparations for an emerging disease; quantifies expenditures necessary for a responsive program; and discusses some issues associated with the proximity of vampire bats to the U.S.-Mexico border.

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]

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]

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.

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]

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]

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]

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.

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]

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.

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.

La Rabia Paralítica Bovina (RPB) es una zoonosis viral ampliamente distribuida en México, su principal reservorio y transmisor es el murciélago hematófago Desmodus rotundus. La presente investigación tiene por objetivo impulsar la formulación de políticas públicas para el diseño de estrategias de prevención y control adecuadas. El área de estudio corresponde a la Mixteca Poblano-Oaxaqueña que presenta las condiciones de altitud, temperatura promedio del trimestre más frío, precipitación del trimestre más seco y vegetación y uso del suelo para la estimación del riesgo potencial mediante la interpolación Kriging. Posteriormente, se aplicó una encuesta a 317 individuos, en donde se asociaron el riesgo a la trasmisión de enfermedades y el daño ocasionado. La población reconoce que la RPB impacta al ganado bovino, porcino, caprino, avícola, asnal y equino. El desarrollo de propuestas de políticas públicas en temas de salud ambiental, como lo es la RPB permiten enfocar las áreas que requieren atención prioritaria y obtener resultados tangibles en: conocimiento de las comunidades de murciélagos, estimación de las áreas potenciales de distribución del murciélago hematófago, control adecuado del mismo, prevención de la RPB y tratamiento del ganado, así como, la atención a las poblaciones humanas que podrían estar en riesgo. A nivel local se podrían generar cambios que promuevan la salud y mejoren la calidad de vida; desde el punto de vista económico el gasto público y privado de un programa de prevención y control es mínimo comparado con las pérdidas económicas que generan los brotes.

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 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.

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.

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.

Rabies transmitted by the common vampire bat is a major public health concern in subtropical and tropical areas of Latin America, and there is some concern that the species will eventually spread into south Texas. The objective of this study was to estimate the total economic impact of the potential spread of vampire bats into south Texas. Data on livestock populations and values in the relevant counties was combined with expected mortality rates to calculate livestock losses. An IMPLAN model of the regional economy was then used to estimate the secondary impacts experienced by other businesses in the region. These impacts were combined with estimates of increased expenditures on post-exposure prophylaxis and animal tests to derive the total economic impact. We estimated the total economic impact would be $7 million to $9.2 million annually if vampire bats spread to south Texas.

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.

La rabia es una enfermedad viral zoonótica ocasionada por un virus ARN del género Lyssavirus de la familia Rhabdoviridae, su principal transmisor es el Desmodus rotundus; la transmisión acontece por penetración del virus contenido en la saliva del transmisor infectado. Una vez inoculado el virus rábico por mordedura de un animal infectado, se produce la primera replicación in situ del virus en las células musculares estriadas, los husos o placas neuromusculares facilitan el acceso del virus a las terminales nerviosas, que se dirige en forma centrípeta hacia la médula espinal y encéfalo. Los principales síntomas incluyen: depresión, incoordinación, paresia de los miembros, decúbito esternal y lateral, opistótonos, salivación abundante, mugidos constantes, agresividad, hiperexcitabilidad, hiperestesia, prurito intenso, manifestaciones de irritación cutánea y muerte. El objetivo del trabajo fue describir las alteraciones histológicas en el SNC (sistema nervioso central) y complejo GHR (ganglio de gasser, hipófisis y rete de mirabile) en un bovino con síntomas neurológicos. Un establecimiento de la ciudad de Valenzuela (en el departamento de Cordillera, Paraguay) presentó muertes en bovinos con manifestaciones neurológicas. Se realizó la necropsia y análisis histopatológico del sistema nervioso central de un bovino criollo, hembra de 5 años. Los principales hallazgos microscópicos incluyeron: infiltrado inflamatorio perivascular mononuclear linfoplasmocitario tipo manguito perivascular, proliferación difusa de células gliales, aislados nódulos gliales, nódulos neuronofágicos, células satélites alrededor de neuronas, células de Purkinje alrededor del cerebelo con uno a varios corpúsculos de Negri en el citoplasma, el complejo de ganglio de Gasser, la rete mirabile e hipófisis con proliferación de células satélites, nódulos neuronofágicos y ganglionitis multifocal no supurativa, neuronas con cambios degenerativos similares a lo identificado en cerebelo, tálamo, cerebro y médula espinal, con presencia de corpúsculo eosinofílico de Negri en el citoplasma de algunas neuronas. Considerando el historial clínico del establecimiento y los hallazgos histopatológicos se concluye con un cuadro severo de daño neurológico a partir de una infección por el virus de la Rabia. Es imprescindible implementar programas estrictos de vacunación profiláctica en establecimientos ganaderos e instar a la denuncia obligatoria a la institución nacional de vigilancia epidemiológica (SENACSA). [ABSTRACT FROM AUTHOR]

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.

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.

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.

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]

Vampire bat control strategies have not changed in México for more than 40 years. Anticoagulants and strychnine are frequently used to reduce bat populations and the prevalence of rabies. Despite these control efforts, vampire bat-borne rabies continues to have a significant economic impact. A new control method is being developed that takes advantage of the reproductive changes induced by phytoestrogens in mammals. In this study, we fed bats the phytoestrogen coumestrol, for 30 days and examined its effect on the reproductive organs of male and female vampire bats in laboratory tests. For males, coumestrol resulted in an increase in weight and loss of the typical histological structure of testes. Treated females had no corpora lutea in their ovaries and fewer primordial folliculi were observed. These results suggest that coumestrol might be a candidate replacement for anti-coagulants used for vampire bat control.

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.

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.

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.)

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]

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.

Introduction Rabies is an important zoonosis that occurs in mammals, with bats acting as Lyssavirus reservoirs in urban, rural and natural areas. Rabies cases in bats have been recorded primarily in urban areas in Northwestern State of São Paulo since 1998. This study investigated the circulation of rabies virus by seeking to identify the virus in the brain in several species of bats in this region and by measuring rabies-virus neutralizing antibody levels in the hematophagous bat Desmodus rotundus. Methods From 2008 to 2012, 1,490 bat brain samples were sent to the Universidade Estadual Paulista (UNESP) Rabies Laboratory in Araçatuba, and 125 serum samples from vampire bats that were captured in this geographical region were analyzed. Results Rabies virus was detected in the brains of 26 (2%) of 1,314 non-hematophagous bats using the fluorescent antibody test (FAT) and the mouse inoculation test (MIT). None of the 176 hematophagous bat samples were positive for rabies virus when a virus detection test was utilized. Out of 125 vampire bat serum samples, 9 (7%) had levels of rabies virus neutralization antibodies (RVNAs) that were higher than 0.5IU/mL; 65% (81/125) had titers between 0.10IU/mL and 0.5IU/mL; and 28% (35/125) were negative for RVNAs using the simplified fluorescent inhibition microtest (SFIMT) in BHK21 cells. The observed positivity rate (1.7%) was higher than the average positivity rate of 1.3% that was previously found in this region. Conclusions The high percentage of vampire bats with neutralizing antibodies suggests that recent rabies virus exposure has occurred, indicating the necessity of surveillance measures in nearby regions that are at risk to avoid diffusion of the rabies virus and possible rabies occurrences.

A raiva transmitida por morcegos hematófagos da espécie Desmodus rotundus representa uma preocupação de saúde pública e causa de importantes prejuízos para a pecuária brasileira. A evidência atual sugere que a ocorrência de raiva está relacionada às características da paisagem, topografia, hidrografia, sistemas de produção animal e usos da terra. Contudo, existem poucos estudos que analisem as possíveis conexões entre fatores geográficos e a diversidade molecular do vírus da raiva, permitindo a compreensão da dinâmica espacial e temporal dos focos de raiva. Um desses trabalhos estabeleceu que a última epizootia de raiva dos herbívoros registrada no leste do estado de São Paulo (na fronteira com Minas Gerais), aconteceu em duas ondas epidêmicas, sendo a primeira em 1998 e, em 1999, a segunda. Considerando esta evidência, o intuito do presente estudo foi analisar casos de raiva em herbívoros na região sudeste de Minas Gerais (2000-2009) e sua possível relação com a epidemia previamente mencionada, incluindo as características geográficas da região. Foram obtidas sequencias parciais dos genes da glicoproteína (539 nt) e da nucleoproteína (414 nt) a partir de 31 isolados de vírus da raiva procedentes de herbívoros. Foi proposta uma árvore filogenética para cada região genômica usando o método de Neighbor joining, fixando o modelo evolutivo Kimura 2 - parâmetros com um nível de bootstrap de 1000 replicações. As sublinhagens genéticas foram localizadas sobre mapas, considerando as áreas de risco para raiva dos herbívoros em São Paulo, assim como as características topográficas e bacias hidrográficas com o intuito de visualizar qualquer padrão aparente de distribuição segundo essas características. As duas árvores filogenéticas mostraram topologias concordantes, sugerindo uma possível origem comum para os surtos que aconteceram ao longo da fronteira SP/MG, ao redor das porções menos elevadas da Serra da Mantiqueira e acompanhando as bacias hidrográficas dos rios Piracicaba/Jaguarí, Paranaíba do Sul, Grande, Pardo e Mogi-Guaçu. Foi possível observar circulação de varias linhagens virais simultaneamente em alguns municípios, possivelmente por causa de sobreposição de surtos. As sequencias de proteína inferidas a partir dos dois genes mostraram mutações sinônimas, excetuando aquelas encontradas entre os resíduos 20 a 200, correspondentes ao domínio externo da glicoproteína. Esta informação salienta a importância da cooperação entre as autoridades sanitárias de ambos os estados para reforçar o programa de controle da doença nas áreas limítrofes.

Reproductive seasonality in Neotropical bats has been assessed to the better understand their reproductive behavior. This knowledge is especially important for the control of Desmodus rotundus population as it is a transmitter of rabies virus. Therefore, we aimed to evaluate the functional activity of testis and epididymis of D. rotundus in dry and rainy seasons under a morphological approach. We observed an increase in tubular diameter and epithelial height of the seminiferous tubules during the rainy season. In the latter, additionally, stereological analysis of the testis showed increased proportion of seminiferous epithelium and reduced percentage of lumen. The sperm number in caput/corpus epididymis increased in rainy season, whereas sperm count and transit time were reduced in cauda region. These alterations were probably related to the recovery of epithelium activities after mating season in dry season. Despite altered nuclear and cytoplasm parameters of Leydig cells between seasons, the volume and number of these cells were constant. Moreover, no change in serum testosterone levels, daily sperm production, and apoptotic index were observed, which indicates that the reproductive pattern in D. rotundus does not change between seasons. Our study offers a baseline for the management of vampire bat population as an attempt to control rabies disease. [ABSTRACT FROM AUTHOR]

Bats are known to harbor many zoonotic viruses, some of which are pathogenic to other mammals while they seem to be harmless in bats. As the interferon (IFN) response represents the first line of defense against viral infections in mammals, it is hypothesized that activation of the IFN system is one of the mechanisms enabling bats to co-exist with viruses. We have previously reported induction of type I IFN in a cell line from the common vampire bat, Desmodus rotundus , upon polyinosinic:polycytidylic acid (poly(I:C)) stimulation. To deepen our knowledge on D. rotundus ’ IFN-I antiviral response, we molecularly characterized three interferon-stimulated genes (ISGs), OAS1 , PKR and ADAR1 , closely implicated in the IFN-I antiviral response, and tested their functionality in our cellular model. We first found that D. rotundus encoded two OAS1 paralogs, OAS1a and OAS1b , and that the functional domains of the four ISGs characterized were highly conserved with those of other mammals. Despite their significant transcription level in the absence of stimulation, the transcription of the four ISGs characterized was enhanced by poly(I:C). In addition, the transcription of OAS1a and OAS1b appears to be differentially regulated. These findings demonstrate an active ISG antiviral response in D. rotundus in which OAS1b may play an important role. [ABSTRACT FROM AUTHOR]