RESUMO
Bats are the second most diverse order of mammals and play a central role in ecosystem dynamics. They are also important reservoirs of potentially zoonotic microorganisms, of which rabies virus is the most lethal among the bat-transmitted zoonotic pathogens. Importantly, recent outbreaks of human rabies have been reported from the Brazilian Amazon. Here we present a survey of bat species and rabies virus (RABV) circulation in a bat assemblage in the Marajó region, northern Brazil. Using data from mist-net captures and bioacoustic sampling, 56 bat species were recorded along the Jacundá River basin over a 10-day expedition in November 2022. For the investigation of RABV, we used the direct fluorescent antibody test (DFAT) and the rapid fluorescent focus inhibition test (RFFIT). In total, 159 bat individuals from 22 species were investigated for RABV. Five adults of the common vampire bat, Desmodus rotundus, showed RABV-specific antibodies in serum samples. Additionally, we report on local residents with injuries caused by D. rotundus bites and the occurrence of colonies of non-hematophagous bats from different species roosting inside human residences. This scenario raises concerns about the risks of new cases of human rabies and other zoonotic diseases associated with bats in the region and highlights the need for epidemiological surveillance and mitigation measures to prevent outbreaks of emerging infectious diseases.
Assuntos
Anticorpos Antivirais , Quirópteros , Surtos de Doenças , Vírus da Raiva , Raiva , Zoonoses , Quirópteros/virologia , Animais , Brasil/epidemiologia , Vírus da Raiva/imunologia , Vírus da Raiva/isolamento & purificação , Vírus da Raiva/classificação , Raiva/epidemiologia , Raiva/veterinária , Raiva/virologia , Humanos , Zoonoses/epidemiologia , Zoonoses/virologia , Anticorpos Antivirais/sangue , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , AdolescenteRESUMO
The causative agent of Chagas disease is Trypanosoma cruzi, which is widely distributed throughout the South American continent and extends into North America. Its occurrence in bats is poorly described and may impact the disease's maintenance and epidemiology. The aim of this study was to detect the agent by PCR assays targeting kDNA and nuclear DNA in the organs of 203 urban bats and rural vampire bats from the Brazilian Atlantic Forest, São Paulo state, during the pandemic period from 2020 to 2022. In total, 6 of the 203 bats (2.97%) were positive for T. cruzi. Infection was detected in 2% (2/101) of Desmodus rotundus, 33% (1/3) of Nyctinomops laticaudatus, 25% (1/4) of Artibeus lituratus, 4% (1/24) of Eumops glaucinus and in 2% (1/41) of Molossus molossus. The gene sequences obtained were assessed for quality and deposited in a public repository. Fruit bats were statistically associated with positivity for T. cruzi. To our knowledge, this study detected T. cruzi for the first time in bats from São Paulo state and in N. laticaudatus and E. glaucinus species.
RESUMO
In addition to zoonotic viral pathogens, bats can also harbor bacterial pathogens, including hemoplasmas (hemotropic mycoplasmas) and Coxiella burnetii. The present study aimed to investigate, using molecular techniques, the presence of hemoplasmas and C. burnetii in spleen samples from vampire bats in northern Brazil. For this purpose, between 2017 and 2019, spleen samples were collected from Desmodus rotundus (n = 228) and Diaemus youngii (n = 1) captured in the states of Pará (n = 207), Amazonas (n = 1), Roraima (n = 18) and Amapá (n = 3). DNA samples extracted from the bat spleen and positive in PCR for the endogenous gapdh gene were subjected to conventional PCR assays for the 16S rRNA, 23S rRNA and RNAse P genes from hemoplasmas and to qPCR based on the IS1111 gene element for C. burnetii. All spleen samples from vampire bats were negative in the qPCR for C. burnetii. Hemoplasmas were detected in 10 % (23/229) of spleen samples using a PCR based on the 16S rRNA gene. Of these, 21.73 % (5/23) were positive for the 23S rRNA gene and none for the RNAseP gene. The seven hemoplasma 16S rRNA sequences obtained were closely related to sequences previously identified in vampire bats from Belize, Peru and Brazil. The 23S rRNA sequence obtained revealed genetic proximity to hemoplasmas from non-hematophagous bats from Brazil and Belize. The analysis revealed different circulating genotypes among Brazilian vampire bats, in addition to a trend towards genera-specific hemoplasma genotypes. The present study contributes to the knowledge of the wide diversity of hemoplasmas in vampire bats.
Assuntos
Quirópteros , Coxiella burnetii , Infecções por Mycoplasma , Animais , Infecções por Mycoplasma/microbiologia , Infecções por Mycoplasma/veterinária , Quirópteros/microbiologia , Brasil/epidemiologia , Coxiella burnetii/genética , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , FilogeniaRESUMO
Bat-mediated human rabies is a viral zoonotic disease that poses a serious threat to the public health of traditional peoples, especially indigenous populations that maintain primitive cultural and social habits, such as the Maxakali ethnic group, located in the southeastern region of Brazil. The sociocultural habit of this population led to the emergence between April and May 2022 of the viral spillover of rabies transmitted by bats, which decimated the lives of four children from this population who maintained contact with this animal as a recreational practice. Because the vampire bats Desmodus rotundus have exceptional ecology and social characteristics that can have important effects on the dynamics of viral dispersion in this indigenous population, I present the dynamics of contact between native children and the bat and the meaning of this relationship, which involves ritualistic and recreational significance. As important as knowing the reasons for this practice is discussing some intrinsic and extrinsic factors that imply risks that intensify the vulnerability of this population to the transmission of the rabies virus at any time. In view of this, I warn of the need to adopt efficient strategies to mitigate the risks of a new emergency in this region. Although emergency containment measures were carried out during the critical period of the outbreak, such animal and environmental control actions must become routine programmatic and structuring interventions. Essential for rabies surveillance in this population is to develop culturally adapted interethnic health education campaigns to guarantee the accessibility of the Maxakali indigenous people to the content taught, so that any attempt at domestication, captivity and recreational practices with bats of any species is discouraged, thus avoiding a possible re-emergence of this anthropozoonosis that has impacted not only the epidemiological scenario in this region, but throughout Brazil, and also throughout Latin America.
Assuntos
Mordeduras e Picadas , Quirópteros , Vírus da Raiva , Raiva , Animais , Criança , Humanos , Raiva/epidemiologia , Raiva/prevenção & controle , Raiva/veterinária , Brasil/epidemiologia , Vírus da Raiva/genética , Ecologia , Mordeduras e Picadas/epidemiologiaRESUMO
Desmodus rotundus, vampire bats, transmit dangerous infections, and brucellosis is a hazardous zoonotic disease, two adversities that coexist in the subtropical and tropical areas of the American continent. Here, we report a 47.89% Brucella infection prevalence in a colony of vampire bats inhabiting the tropical rainforest of Costa Rica. The bacterium induced placentitis and fetal death in bats. Wide-range phenotypic and genotypic characterization placed the Brucella organisms as a new pathogenic species named Brucella nosferati sp. nov., isolated from bat tissues, including the salivary glands, suggesting feeding behavior might favor transmission to their prey. Overall analyses placed B. nosferati as the etiological agent of a reported canine brucellosis case, demonstrating its potential for infecting other hosts. To assess the putative prey hosts, we analyzed the intestinal contents of 14 infected and 23 non-infected bats by proteomics. A total of 54,508 peptides sorted into 7,203 unique peptides corresponding to 1,521 proteins were identified. Twenty-three wildlife and domestic taxa, including humans, were foraged by B. nosferati-infected D. rotundus, suggesting contact of this bacterium with a broad range of hosts. Our approach is appropriate for detecting, in a single study, the prey preferences of vampire bats in a diverse area, demonstrating its suitability for control strategies where vampire bats thrive. IMPORTANCE The discovery that a high proportion of vampire bats in a tropical area is infected with pathogenic Brucella nosferati and that bats forage on humans and many wild and domestic animals is relevant from the perspective of emerging disease prevention. Indeed, bats harboring B. nosferati in their salivary glands may transmit this pathogenic bacterium to other hosts. This potential is not trivial since, besides the demonstrated pathogenicity, this bacterium possesses all the required virulent arsenal of dangerous Brucella organisms, including those that are zoonotic for humans. Our work has settled the basis for future surveillance actions in brucellosis control programs where these infected bats thrive. Moreover, our strategy to identify the foraging range of bats may be adapted for exploring the feeding habits of diverse animals, including arthropod vectors of infectious diseases, and therefore of interest to a broader audience besides experts on Brucella and bats.
Assuntos
Brucella , Brucelose , Quirópteros , Humanos , Animais , Cães , Estados Unidos , Animais Domésticos , Quirópteros/microbiologia , Animais Selvagens , Brucelose/veterináriaRESUMO
The control of vampire bat rabies (VBR) in Brazil is based on the culling of Desmodus rotundus and the surveillance of outbreaks caused by D. rotundus in cattle and humans in addition to vaccination of susceptible livestock. The detection of anti-rabies antibodies in vampire bats indicates exposure to the rabies virus, and several studies have reported an increase of these antibodies following experimental infection. However, the dynamics of anti-rabies antibodies in natural populations of D. rotundus remains poorly understood. In this study, we took advantage of recent outbreaks of VBR among livestock in the Sao Paulo region of Brazil to test whether seroprevalence in D. rotundus reflects the incidence of rabies in nearby livestock populations. Sixty-four D. rotundus were captured during and after outbreaks from roost located in municipalities belonging to three regions with different incidences of rabies in herbivores. Sixteen seropositive bats were then kept in captivity for up to 120 days, and their antibodies and virus levels were quantified at different time points using the rapid fluorescent focus inhibition test (RFFIT). Antibody titers were associated with the occurrence of ongoing outbreak, with a higher proportion of bats showing titer >0.5 IU/ml in the region with a recent outbreak. However, low titers were still detected in bats from regions reporting the last outbreak of rabies at least 3 years prior to sampling. This study suggests that serological surveillance of rabies in vampire bats can be used as a tool to evaluate risk of outbreaks in at risk populations of cattle and human.
RESUMO
Outbreaks of human rabies transmitted by hematophagous bats occurred in 2018 in Pará state, Brazil, eastern Amazon, after 12 years of no record of the disease. Thus, it is necessary to understand the epidemiological characteristics of these attacks to protect the local population. This study aimed to characterize the bat bite populations in the municipality of São João da Ponta, Pará State, Brazil, in 2013-2015. The Notifiable Diseases Information System (SINAN) database was used to identify the five individuals who sought medical care during the study period (seeds). Other individuals who were attacked during the same period but did not seek medical care (n = 61) were reached by snowball sampling, and a descriptive analysis was performed based on information obtained from questionnaires. Majority of the interviewees were men (92.4%; 61/66) and adults aged 20-50 years (69.9%; 46/66) and had <4 years of formal school education (86.3%; 57/66). Additionally, most of them were rural residents (92.4%; 61/66) and crab fishermen (79.3%; 53/66). The interviewees (92.4%; 61/66) identified mangroves of the Mãe Grande de Curuçá extractive reserve, where groups of fishermen sometimes gather for several days for crab fishing, often living in improvised dwellings without walls and covered by tarps or straw (88.8%; 56/66), conducive to attacks by vampire bats. Overall, 42.4% (28/66) of the participants had been bitten more than four times throughout their life. The median number of attacks over the participant's lifetime was 3.11 (range, 1-23). Participants were unaware of the risk of contracting rabies from the bite (95.4%; 65/66). These results suggest that vampire bat attacks are essentially an occupational hazard in the study region. Moreover, for each reported attack, there were at least 12.2 unreported cases. Thus, the study highlights the need to develop strategies for prophylactic treatment of this population.
Assuntos
Mordeduras e Picadas , Braquiúros , Quirópteros , Vírus da Raiva , Raiva , Adulto , Animais , Mordeduras e Picadas/veterinária , Brasil/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Raiva/epidemiologia , Raiva/prevenção & controle , Raiva/veterinária , Adulto JovemRESUMO
Some nonhuman animals form adaptive long-term cooperative relationships with nonkin that seem analogous in form and function to human friendship [1-4]. However, it remains unclear how these bonds initially form, especially when they entail investments of time and energy. Theory suggests individuals can reduce the risk of exploitation by initially spreading out smaller cooperative investments across time [e.g., 5] or partners [6], then gradually escalating investments in more cooperative partnerships [7]. Despite its intuitive appeal, this raising-the-stakes model [7] has gained surprisingly scarce empirical support. Although human strangers do "raise the stakes" when making bids in cooperation games [8], there has been no clear evidence for raising the stakes during formation of social bonds in nature. Existing studies are limited to cooperative interactions with severe power asymmetries (e.g., the cleaner-client fish mutualism [9]) or snapshots of a single behavior within established relationships (grooming in primates [10-13]). Raising the stakes during relationship formation might involve escalating to more costly behaviors. For example, individuals could "test the waters" by first clustering for warmth (no cost), then conditionally grooming (low cost), and eventually providing coalitionary support (high cost). Detecting such a pattern requires introducing random strangers and measuring the emergence of natural helping behaviors that vary in costs. We performed this test by tracking the emergence of social grooming and regurgitated food donations among previously unfamiliar captive vampire bats (Desmodus rotundus) over 15 months. We found compelling evidence that vampire bats selectively escalate low-cost grooming before developing higher-cost food-sharing relationships.
Assuntos
Quirópteros/psicologia , Comportamento Cooperativo , Comportamento Alimentar , Animais , Feminino , Masculino , PanamáRESUMO
The life history strategy of common vampire bats (Desmodus rotundus) suggests that learning might play a role in development of their foraging skills. We took advantage of 12 captive births in a study colony of vampire bats to test the role of past experience in two aspects of feeding. First, we compared preferences for blood temperature in 32 wild-born vampire bats versus 11 captive-born vampire bats that had only previously fed on blood of ambient temperature or colder. We found no evidence for a preference in either group for blood presented at 4 °C versus 37 °C. Second, we tested whether captive-born vampire bats with no previous experience of feeding on live animals could successfully feed on a live chicken. Five of 12 naïve captive-born bats were able to bite the chicken and draw blood, but only one bat gained more than 5% of body mass. We were unable to reasonably compare their feeding performance with that of wild-born bats because only two of three wild-born, short-term captive bats fed on the chicken and none of the seven wild-born, long-term captive mothers attempted to feed. This unexpected lack of feeding might be due to a previously reported age-dependent neophobia. When six of the captive-born bats were released in the wild, they appeared to feed successfully because they survived for more than three consecutive nights. We suggest further tests that would better clarify the role of learning in the development of foraging in vampire bats.
RESUMO
Molecular phylogenetic studies have revealed the growing diversity of bat trypanosomes. Here, 14 isolates from blood samples of the vampire bat Desmodus rotundus (Phyllostomidae) from Rio de Janeiro, Southeast Brazil, were cultivated, and morphologically and molecularly characterized. All isolates represent a novel species named Trypanosoma madeirae n. sp. positioned in the Neobat lineage of the clade T. cruzi. The Neobat lineage also comprises closely related trypanosomes of clades Neotropic 1, 2 and 3 from diverse phyllostomid species. Trypanosomes of Neotropic 1, found in Trachops cirrhosus and Artibeus jamaicensis (phyllostomids), likely represent a different species or genotype closely related to T. madeirae. Consistent with its phylogenetic positioning, T. madeirae differs from Trypanosoma cruzi in morphology of both epimastigote and trypomastigote culture forms and does not infect Triatoma infestans. Similar to its closest relatives of Neobat lineage, T. madeirae was unable to develop within mammalian cells. To date, PCR-surveys on archived blood/liver samples unveiled T. madeirae exclusively in D. rotundus from Southern to Northern Brazil. The description of a new species of bat trypanosome associated with vampire bats increases the repertoire of trypanosomes infecting D. rotundus, currently comprised of Trypanosoma cruzi, T. cruzi marinkellei, Trypanosoma dionisii, Trypanosoma rangeli, Trypanosoma pessoai, and Trypanosoma madeirae.