RESUMO

Bats are a diverse and ecologically important group of mammals that exhibit remarkable diversity in their feeding habits. These diverse feeding habits are thought to be reflected in the composition and function of their gut microbiota, which plays important roles in nutrient acquisition, immune function, and overall health. Despite the rich biodiversity of bat species in South America, there is a lack of microbiome studies focusing on bats from this region. Such studies could offer major insights into conservation efforts and the preservation of biodiversity in South America. In this work, we aimed to compare the gut microbiota of four bat species with different feeding habits from Southern Brazil, including nectarivorous, frugivorous, insectivorous, and hematophagous bats. Our findings demonstrate that feeding habits can have a significant impact on the diversity and composition of bat gut microbiotas, with each species exhibiting unique metabolic potentials related to their dietary niches. In addition, the identification of potentially pathogenic bacteria suggests that the carriage of microbial pathogens by bats may vary, depending on feeding habits and host-specific factors. These findings provide novel insights into the relationship between bat feeding habits and gut microbiota composition, highlighting the need to promote diverse habitats and food sources to support these ecologically important species.

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In this work, we examined the levels of vitamin E in the heart, liver, and kidneys of four species of adult male bats with distinct feeding habits. Our results indicate consistent vitamin E levels in the heart across all four bat species, suggesting the presence of regulatory mechanisms. Additionally, the liver displayed notably higher vitamin E levels in nectarivorous and frugivorous bats, while hematophagous bats exhibited lower levels, indicating a link between dietary intake and liver vitamin E levels. Furthermore, correlation analysis provided additional insights into the relationships between vitamin E and key antioxidant parameters in the livers of bats. On the other hand, no correlation was observed between vitamin E and key antioxidant parameters in the heart. Intriguingly, vitamin E was not detected in the kidneys, likely due to physiological factors and the prioritization of vitamin E mobilization in the heart, where it serves critical physiological functions. This unexpected absence of vitamin E in bat kidneys highlights the unique metabolic demands and prioritization of vitamin mobilization in wild animals like bats, compared to conventional animal models. These findings provide insight into the intricate distribution and utilization of vitamin E in bats, emphasizing the influence of dietary intake and metabolic adaptations on vitamin E levels in different organs.

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Bats represent the second order of mammals with the highest number of species worldwide with over 1,616 species, and almost 10% of them are recorded in Mexico. These mammals have a great diversity of ectoparasites, in particular soft ticks of the genus Ornithodoros. Desmodus rotundus is one of the bat species that has scarcely been studied in terms of tick species richness in Mexico, with three tick species reported in five of the 32 Mexican states. For this reason, the aim of the present work was to identify ticks associated with D. rotundus from Central Mexico. Fieldwork was undertaken in the municipality El Marqués, Ejido Atongo A, Querétaro, Mexico. Bats were captured using mist nets and were visually inspected for tick presence. The ectoparasites were identified morphologically and molecularly with the use of mitochondrial markers 16SrDNA and cytochrome oxidase subunit I (COI). A total of 30 D. rotundus (1 female, 29 males) were captured, from which 20 larvae identified as Ornithodoros yumatensis were recovered. Molecular analysis confirmed the presence of this species with identity values of 99-100% with sequences of this species from the southwestern US, and the Yucatán Peninsula, Mexico. This is the first report of ticks associated with bats for the state of Querétaro, providing the first sequences of the COI gene from Mexican populations of O. yumatensis and shows an increase in the distribution of this soft tick across Central Mexico.

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Unlike most animals, most bats cannot synthesize vitamin C endogenously. Consequently, this vitamin must be obtained from the diet. Among the bat species, there are several food groups, such as frugivorous, nectarivorous, insectivorous, and hematophagous. In this work, we measured and compared vitamin C levels in different organs of four species of bats, all collected in southern Brazil. When analyzing and comparing the levels of vitamin C in the four bat species, (regardless of the organ), no significant differences were observed. However, when analyzing and comparing the levels of vitamin C in the four organs (regardless of the species), significant differences were observed, with the highest concentrations in the heart, followed by the liver and brain, while the lowest concentration was measured in the kidneys. Additional differences in the levels of Vitamin C were only observed when each organ was analyzed according to the species/diet. These results indicate a high degree of metabolic homeostasis in bats despite the marked difference in the type of diet.

RESUMO

Desmodus rotundus bats show a complex social structure and developed adaptive characteristics, considered key features of a pathogen disseminator, such as the rabies virus, among bats and other mammals, including cattle and humans. Our aim was to understand the correlation between the environment and the ecological features of these bats in bovine rabies outbreaks. Geostatistical analyses were performed, covering 104 cattle positives for rabies, between 2016 and 2018, in 25 municipalities, in addition to the characteristics of D. rotundus colonies mapped during this period in the state of São Paulo, Brazil. Data from the shelters showed that 86.15% were artificial, mainly abandoned houses (36.10%) and manholes (23.87%), in addition to demonstrating a correlation between these shelters and a higher concentration of bovine rabies cases. Due to their adaptive capacity, these bats choose shelters close to the food source, such as livestock. In Brazil, D. rotundus is the main transmitter of rabies and the cause of outbreaks in cattle and deaths in humans, considering the advance of humans in previously preserved ecosystems. There seems to be a correlation between the impact of anthropic changes on the environment, mainly for the expansion of pasture for cattle and the outbreaks of bovine rabies in this area.

RESUMO

In the Neotropical region, the white-winged vampire bat (Diaemus youngi) is the rarest of the three species of vampire bats. This bat species feeds preferentially on bird blood, and there is limited information on the viruses infecting D. youngi. Hence, this study aimed to expand the knowledge about the viral diversity associated with D. youngi by sampling and pooling the lungs, liver, kidneys, heart, and intestines of all animals using high-throughput sequencing (HTS) on the Illumina MiSeq platform. A total of three complete and 10 nearly complete circular virus genomes were closely related to gemykrogvirus (Genomoviridae family), smacovirus (Smacoviridae family), and torque teno viruses (TTVs) (Anelloviridae family). In addition, three sequences of bat paramyxovirus were detected and found to be closely related to viruses reported in Pomona roundleaf bats and rodents. The present study provides a snapshot of the viral diversity associated with white-winged vampire bats and provides a baseline for comparison to viruses detected in future outbreaks.

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Pathogenicity and pathology of rabies virus (RABV) varies according to the variant, but the mechanisms are not completely known. In this study, gene expression profile in brains of mice experimentally infected with RABV isolated from a human case of dog rabies (V2) or vampire bat-acquired rabies (V3) were analyzed. In total, 138 array probes associated with 120 genes were expressed differentially between mice inoculated with V2 and sham-inoculated control mice at day 10 post-inoculation. A single probe corresponding to an unannotated gene was identified in V3 versus control mice. Gene ontology (GO) analysis revealed that all of the genes upregulated in mice inoculated with V2 RABV were involved in the biological process of immune defense against pathogens. Although both variants are considered pathogenic, inoculation by the same conditions generated different gene expression results, which is likely due to differences in pathogenesis between the dog and bat RABV variants. This study demonstrated the global gene expression in experimental infection due to V3 wild-type RABV, from the vampire bat Desmodus rotundus, an important source of infection for humans, domestic animals and wildlife in Latin America.

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Desmodus rotundus is one of the wild animal species that has benefitted by habitat alteration and its population has increased due to livestock activities. Common vampire bat population management has been implemented across Mexico due to the economic losses to livestock production, inflicted by vampire bat attacks and rabies transmission. Yucatan is one of the seven most impacted states in Mexico by the number of cattle rabies cases per year. However, there is little research on D. rotundus populations such as the frequency and attack patterns to cattle. This study's objective was to analyze the relationship between D. rotundus abundance and number of bovines attacked in livestock landscapes in Yucatan. The study used data gathered by the State Committee for Protection and Promotion of Livestock in Yucatan through the National Campaign for Common Vampire Bat Population Control. Data collected from January 2014 to December 2017 was analyzed using Pearson correlation. Distribution maps on Desmodus rotundus abundance and number of bovines attacked were also created. Higher abundance of Desmodus rotundus and number of cattle attacks were observed in the central region of Yucatan, particularly in Izamal municipality. Positive correlations were found between (1) abundance of Desmodus rotundus and number of cattle in the region, (2) total number of cattle and number of cattle attacked, and (3) abundance of Desmodus rotundus and number of cattle attacked. We can conclude that there is a relationship between Desmodus rotundus abundance and frequency of cattle attacks in most municipalities across Yucatan. Some outstanding exceptions were observed, which require further detailed investigations.

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The vampire bat Desmodus rotundus is the main transmitter of domestic herbivorous rabies, which causes economic losses in cattle raising, being a serious public health problem. The use of Geographic Information Systems (GIS) allows the spatial monitoring of these bats' shelters, which is an efficient way to prevent and control rabies. This study located shelters of D. rotundus in the Eastern Center region of São Paulo state and identified the types of shelters used (natural or artificial), their proximity to water, sexual composition, and a population estimated of the colonies. Searches were carried out by colonies of vampire bats in natural and artificial shelters from 2002 to 2004, covering 18 municipalities. After being located, the shelters were georeferenced, being recorded the nature of the shelter (natural or artificial), use (shelters of males, maternities, digestive), and estimated population. The data were incorporated into a GIS, producing a thematic map of the shelters location and its distance from the local water bodies. There were found 1.567 D. rotundus distributed in 94 shelters, where only six shelters (6.38%) were natural (caves). Most shelters (79.78%) were sparsely populated, with up to 15 bats, including male shelters (46 shelters) and 30 maternities (63.82% of maternities). Five shelters (5.37%) had between 50 and 100 bats and only two shelters (2.15%) had a population greater than 100 bats. Sixs helters…(AU)

O morcego hematófago Desmodus rotundus é o principal transmissor da raiva dos herbívoros domésticos, o qual causa prejuízos econômicos na pecuária, além de ser um sério problema de saúde pública. O uso de Sistemas de Informações Geográficas (SIG) permite o monitoramento espacial dos abrigos destes morcegos, sendo uma forma eficiente na prevenção e controle da raiva. Este estudo localizou abrigos de D. rotundus na região Centro Leste do estado de São Paulo e identificou os tipos de abrigos utilizados (naturais ou artificiais), sua proximidade a corpos de água, composição sexual e população estimada das colônias. Foram realizadas buscas por colônias de morcegos hematófagos em abrigos naturais e artificiais durante 2002 a 2004, abrangendo 18 municípios. Após serem localizados, os abrigos foram georreferenciados registrados quanto à natureza do abrigo (natural ou artificial), utilização (abrigos de machos, maternidades, digestório) e população estimada. Os dados foram incorporados em um SIG, produzindo-se um mapa temático da localização dos abrigos e sua distância dos corpos hídricos locais. Foram encontrados cerca de 1567 indivíduos da espécie D. rotundus distribuídos em 94 abrigos, onde apenas seis abrigos (6,38%) eram naturais (grutas). A maioria dos abrigos (79,78%) era pouco populoso, com até 15 morcegos, incluindo os abrigos de machos (46 abrigos) e 30 maternidades (63,82% das maternidades). Cinco abrigos (5,37%) possuíam entre 50 e 100 morcegos e apenas dois abrigos (2,15%) possuíam uma população superior a 100 morcegos. Seis abrigos...(AU)

El murciélago vampiro Desmodus rotundus es el principal transmisor de la rabia en los herbívoros domésticos, lo que provoca pérdidas económicas en el ganado, además de ser un grave problema de salud pública. El uso de Sistemas de Información Geográfica (SIG) permite el monitoreo espacial de los refugios de estos murciélagos, siendo una forma eficiente de prevenir y controlar la rabia. Este estudio localizó refugios de D. rotundus en la región Centro-Este del estado de São Paulo e identificó los tipos de refugios utilizados (naturales o artificiales), su proximidad a cuerpos de agua, composición sexual y población estimada de las colonias. Se realizaron búsquedas de colonias de murciélagos vampiros en refugios naturales y artificiales durante 2002 a 2004, abarcando 18 municipios. Una vez ubicados, se georreferenciaron los refugios y se registró la naturaleza del refugio (natural o artificial), uso (refugios masculinos, maternidades, digestivo) y población estimada. Los datos se incorporaron a un SIG, produciendo un mapa temático de la ubicación de los refugios y su distancia a los cuerpos de agua locales. Se encontraron 1567 individuos de la especie D. rotundus distribuidos en 94 refugios, donde solo seis refugios (6,38%) eran naturales (grutas). La mayoría delos refugios (79,78%) estaban escasamente poblados, con hasta 15 murciélagos, incluidos los refugios para machos (46 refugios) y 30 criaderos (63,82% de los criaderos). Cinco refugios (5,37%) tenían entre 50 y 100 murciélagos y solo dos refugios (2,15%) tenían una población superior a 100 murciélagos. Seis albergues...(AU)

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RESUMO

Rabies is an acute, progressive encephalitis caused by a lyssavirus, with the highest case fatality of any conventional infectious disease. More than 17 different lyssaviruses have been described, but rabies virus is the most widely distributed and important member of the genus. Globally, tens of thousands of human fatalities still occur each year. Although all mammals are susceptible, most human fatalities are caused by the bites of rabid dogs, within lesser developed countries. A global plan envisions the elimination of human rabies cases caused via dogs by the year 2030. The combination of prophylaxis of exposed humans and mass vaccination of dogs is an essential strategy for such success. Regionally, the Americas are well on the way to meet this goal. As one example of achievement, Costa Rica, a small country within Central America, reported the last autochthonous case of human rabies transmitted by a dog at the end of the 1970s. Today, rabies virus transmitted by the common vampire bat, Desmodus rotundus, as well as other wildlife, remains a major concern for humans, livestock, and other animals throughout the region. This review summarizes the historical occurrence of dog rabies and its elimination in Costa Rica, describes the current occurrence of the disease with a particular focus upon affected livestock, discusses the ecology of the vampire bat as the primary reservoir relevant to management, details the clinical characteristics of recent human rabies cases, and provides suggestions for resolution of global challenges posed by this zoonosis within a One Health context.

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RESUMO

The common vampire bat (Desmodus rotundus) is a hematophagous species responsible for paralytic rabies and bite damage that affects livestock, humans and wildlife from Mexico to Argentina. Current measures to control vampires, based upon coumarin-derived poisons, are not used extensively due in part to the high cost of application, risks for bats that share roosts with vampires and residual environmental contamination. Observations that vampire bat bites may induce resistance in livestock against vampire bat salivary anticoagulants encourage research into novel vaccine-based alternatives particularly focused upon increasing livestock resistance to vampire salivary components. We evaluated the action of vampire bat saliva-Freund's incomplete adjuvant administered to sheep with anticoagulant responses induced by repeated vampire bites in a control group and examined characteristics of vampire bat salivary secretion. We observed that injections induced a response against vampire bat salivary anticoagulants stronger than by repeated vampire bat bites. Based upon these preliminary findings, we hypothesize the utility of developing a control technique based on induction of an immunologically mediated resistance against vampire bat anticoagulants and rabies virus via dual delivery of appropriate host and pathogen antigens. Fundamental characteristics of host biology favor alternative strategies than simple culling by poisons for practical, economical, and ecologically relevant management of vampire populations within a One Health context.

Assuntos

RESUMO

The vampire bat Desmodus rotundus is the main transmitter of domestic herbivorous rabies, which causes economic losses in cattle raising, being a serious public health problem. The use of Geographic Information Systems (GIS) allows the spatial monitoring of these bats' shelters, which is an efficient way to prevent and control rabies. This study located shelters of D. rotundus in the Eastern Center region of São Paulo state and identified the types of shelters used (natural or artificial), their proximity to water, sexual composition, and a population estimated of the colonies. Searches were carried out by colonies of vampire bats in natural and artificial shelters from 2002 to 2004, covering 18 municipalities. After being located, the shelters were georeferenced, being recorded the nature of the shelter (natural or artificial), use (shelters of males, maternities, digestive), and estimated population. The data were incorporated into a GIS, producing a thematic map of the shelter’s location and its distance from the local water bodies. There were found 1.567 D. rotundus distributed in 94 shelters, where only six shelters (6.38%) were natural (caves). Most shelters (79.78%) were sparsely populated, with up to 15 bats, including male shelters (46 shelters) and 30 maternities (63.82% of maternities). Five shelters (5.37%) had between 50 and 100 bats and only two shelters (2.15%) had a population greater than 100 bats. Sixs helters

O morcego hematófago Desmodus rotundus é o principal transmissor da raiva dos herbívoros domésticos, o qual causa prejuízos econômicos na pecuária, além de ser um sério problema de saúde pública. O uso de Sistemas de Informações Geográficas (SIG) permite o monitoramento espacial dos abrigos destes morcegos, sendo uma forma eficiente na prevenção e controle da raiva. Este estudo localizou abrigos de D. rotundus na região Centro Leste do estado de São Paulo e identificou os tipos de abrigos utilizados (naturais ou artificiais), sua proximidade a corpos de água, composição sexual e população estimada das colônias. Foram realizadas buscas por colônias de morcegos hematófagos em abrigos naturais e artificiais durante 2002 a 2004, abrangendo 18 municípios. Após serem localizados, os abrigos foram georreferenciados registrados quanto à natureza do abrigo (natural ou artificial), utilização (abrigos de machos, maternidades, digestório) e população estimada. Os dados foram incorporados em um SIG, produzindo-se um mapa temático da localização dos abrigos e sua distância dos corpos hídricos locais. Foram encontrados cerca de 1567 indivíduos da espécie D. rotundus distribuídos em 94 abrigos, onde apenas seis abrigos (6,38%) eram naturais (grutas). A maioria dos abrigos (79,78%) era pouco populoso, com até 15 morcegos, incluindo os abrigos de machos (46 abrigos) e 30 maternidades (63,82% das maternidades). Cinco abrigos (5,37%) possuíam entre 50 e 100 morcegos e apenas dois abrigos (2,15%) possuíam uma população superior a 100 morcegos. Seis abrigos...

El murciélago vampiro Desmodus rotundus es el principal transmisor de la rabia en los herbívoros domésticos, lo que provoca pérdidas económicas en el ganado, además de ser un grave problema de salud pública. El uso de Sistemas de Información Geográfica (SIG) permite el monitoreo espacial de los refugios de estos murciélagos, siendo una forma eficiente de prevenir y controlar la rabia. Este estudio localizó refugios de D. rotundus en la región Centro-Este del estado de São Paulo e identificó los tipos de refugios utilizados (naturales o artificiales), su proximidad a cuerpos de agua, composición sexual y población estimada de las colonias. Se realizaron búsquedas de colonias de murciélagos vampiros en refugios naturales y artificiales durante 2002 a 2004, abarcando 18 municipios. Una vez ubicados, se georreferenciaron los refugios y se registró la naturaleza del refugio (natural o artificial), uso (refugios masculinos, maternidades, digestivo) y población estimada. Los datos se incorporaron a un SIG, produciendo un mapa temático de la ubicación de los refugios y su distancia a los cuerpos de agua locales. Se encontraron 1567 individuos de la especie D. rotundus distribuidos en 94 refugios, donde solo seis refugios (6,38%) eran naturales (grutas). La mayoría delos refugios (79,78%) estaban escasamente poblados, con hasta 15 murciélagos, incluidos los refugios para machos (46 refugios) y 30 criaderos (63,82% de los criaderos). Cinco refugios (5,37%) tenían entre 50 y 100 murciélagos y solo dos refugios (2,15%) tenían una población superior a 100 murciélagos. Seis albergues...

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RESUMO

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

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

Assuntos

RESUMO

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

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

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RESUMO

Vampire bats became the main reservoir of rabies in Latin America, where the disease remains one of the most important viral zoonoses affecting humans and livestock. In Peru, the most affected livestock are cattle. The official data of 1,729 cases of bovine rabies were evaluated between 2003 and 2017 through a descriptive analysis, decomposition of the time-series and spatio-temporal analyses. Although the cases did not present a defined seasonality, the trend seemed to increase for several years. The bovine rabies cases are more frequent in the inter-Andean valleys than in other regions of the Amazon plains. The highest case density was observed in the regions of Ayacucho, Cuzco and Apurímac, all located in the Andes. It is necessary to review the current national program for the prevention and control of rabies in livestock, incorporating concepts of the ecology of vampire bats, as well as the prediction of the infection waves geographic and temporal spread. These approaches could improve the efficiency of other current prevention measures that have not shown the expected control effects, such as indiscriminate culling of vampire bats.

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

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Vampire bat-transmitted human rabies was first recognized in Trinidad during a major outbreak during the first half of the 20th century. To date, Trinidad is the only Caribbean island with vampire bat-transmitted rabies. Herein, we summarized the epidemiological situation of rabies in Trinidad during the period 1971-2015 through the analysis of field and laboratory records. During the study period, 259 domestic and wild animal rabies cases were laboratory confirmed with an annual median of 2 animal rabies cases. Over the 45 years, five significant epizootic events occurred (in 1974, 1997-1998, 2000, 2010 and 2012-2013) over which there was a significant increasing trend for the occurrence of rabies cases. The highest number of cases (87 cases) occurred during the 1997-1998 event, and the rabies positive proportion, was highest (0.7, 95% CI 0.52-0.84) for the year 2000. Rabies risk was highest for cattle (negative binomial parameter estimate 4.84, 95% CI 3.45-6.76), although numerous rabies cases were seen in the caprine population during the study period. In light of this finding, consideration should be given to including the small ruminant population in the national rabies vaccination program. Outbreaks affected mainly the counties of St. Patrick and St. George East, with epidemic progression outwards, and these areas should be prioritized for prevention and control efforts.

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Rabies virus is the only Lyssavirus species found in the Americas. In discussions about rabies, Latin America and the Caribbean are often grouped together. Our study aimed to independently analyse the rabies situation in the Caribbean and examine changes in rabies spatiotemporal epidemiology. A questionnaire was administered to the 33 member countries and territories of the Caribbean Animal Health Network (CaribVET) to collect current data, which was collated with a literature review. Rabies was endemic in ten Caribbean localities, with the dog, mongoose, and vampire bat identified as enzootic reservoirs. The majority of animal cases occurred in Puerto Rico, the Dominican Republic, and Haiti, while human cases only consistently occurred in the latter two areas. Rabies vaccination was conducted for high-risk animal populations with variable coverage, and rabies diagnostic capacities varied widely throughout the region. Illegal importation and natural migration of animals may facilitate the introduction of rabies virus variants into virus-naïve areas. Passive surveillance, together with enhanced methods and serological screening techniques, can therefore be of value. The insularity of the Caribbean makes it ideal for conducting pilot studies on reservoir host population management. Best practice guidelines developed for these reservoir hosts can be individually modified to the epidemiological status and available resources within each locality.

RESUMO

Bats are a diverse radiation of mammals of enduring interest for understanding the evolution of sensory specialization. Colour vision variation among species has previously been linked to roosting preferences and echolocation form in the suborder Yinpterochiroptera, yet questions remain about the roles of diet and habitat in shaping bat visual ecology. We sequenced OPN1SW and OPN1LW opsin genes for 20 species of leaf-nosed bats (family Phyllostomidae; suborder Yangochiroptera) with diverse roosting and dietary ecologies, along with one vespertilionid species (Myotis lavali). OPN1LW genes appear intact for all species, and predicted spectral tuning of long-wavelength opsins varied among lineages. OPN1SW genes appear intact and under purifying selection for Myotis lavali and most phyllostomid bats, with two exceptions: (a) We found evidence of ancient OPN1SW pseudogenization in the vampire bat lineage, and loss-of-function mutations in all three species of extant vampire bats; (b) we additionally found a recent, independently derived OPN1SW pseudogene in Lonchophylla mordax, a cave-roosting species. These mutations in leaf-nosed bats are independent of the OPN1SW pseudogenization events previously reported in Yinpterochiropterans. Therefore, the evolution of monochromacy (complete colour blindness) has occurred in both suborders of bats and under various evolutionary drivers; we find independent support for the hypothesis that obligate cave roosting drives colour vision loss. We additionally suggest that haematophagous dietary specialization and corresponding selection on nonvisual senses led to loss of colour vision through evolutionary sensory trade-off. Our results underscore the evolutionary plasticity of opsins among nocturnal mammals.

Assuntos

RESUMO

The blood-feeding behavior of Desmodus rotundus made this bat a potential vector of rabies virus and a public health issue. Consequently, the better understanding of its reproductive biology becomes valuable for the development of methods to control its population. In this study, we described morphological aspects of epithelial cells in D. rotundus' epididymis using light and transmission electron microscopy methods. The duct compartment was the main component of initial segment (83%), caput (90%), corpus (88%) and cauda (80%) regions. The epithelium lining the duct presented a progressive decrease in its height from initial segment to cauda regions. Moreover, the morphology of each cell type was the same along the entire duct. Similarly to rodents, columnar-shaped principal cells were the most abundant cell type throughout the epididymis, followed by basal and clear cells. Differently in rat and mice, the frequency of clear cells did not increase in the epididymis cauda, whereas the proportion of principal and basal cells was greater in this region. Furthermore, D. rotundus presented goblet-shaped clear cells with the nucleus located in the apical portion of the epididymal epithelium. This cellular portion also presented electron-lucid vesicles of different sizes that may correspond to vesicles enriched with proteins related to proton secretion. In addition to the findings regarding clear cells' structural organization, basal cells presented scarce cytoplasm and no axiopodia. Taken these findings together, we suggest that the mechanism of luminal acidification may have other pathways in D. rotundus than those described in rodents.

Assuntos