scholarly journals The emergence of vampire bat rabies in Uruguay within a historical context

2019 ◽  
Vol 147 ◽  
Author(s):  
G. Botto Nuñez ◽  
D. J. Becker ◽  
R. K. Plowright

AbstractPathogen spillover from wildlife to humans or domestic animals requires a series of conditions to align with space and time. Comparing these conditions between times and locations where spillover does and does not occur presents opportunities to understand the factors that shape spillover risk. Bovine rabies transmitted by vampire bats was first confirmed in 1911 and has since been detected across the distribution of vampire bats. However, Uruguay is an exception. Uruguay was free of bovine rabies until 2007, despite high-cattle densities, the presence of vampire bats and a strong surveillance system. To explore why Uruguay was free of bovine rabies until recently, we review the historic literature and reconstruct the conditions that would allow rabies invasion into Uruguay. We used available historical records on the abundance of livestock and wildlife, the vampire bat distribution and occurrence of rabies outbreaks, as well as environmental modifications, to propose four alternative hypotheses to explain rabies virus emergence and spillover: bat movement, viral invasion, surveillance failure and environmental changes. While future statistical modelling efforts will be required to disentangle these hypotheses, we here show how a detailed historical analysis can be used to generate testable predictions for the conditions leading to pathogen spillover.

2021 ◽  
Vol 8 ◽  
Author(s):  
Jane Megid ◽  
Julio Andre Benavides Tala ◽  
Laís Dário Belaz Silva ◽  
Fernando Favian Castro Castro ◽  
Bruna Letícia Devidé Ribeiro ◽  
...  

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.


Author(s):  
Michael Dee ◽  
David Wengrow ◽  
Andrew Shortland ◽  
Alice Stevenson ◽  
Fiona Brock ◽  
...  

The Egyptian state was formed prior to the existence of verifiable historical records. Conventional dates for its formation are based on the relative ordering of artefacts. This approach is no longer considered sufficient for cogent historical analysis. Here, we produce an absolute chronology for Early Egypt by combining radiocarbon and archaeological evidence within a Bayesian paradigm. Our data cover the full trajectory of Egyptian state formation and indicate that the process occurred more rapidly than previously thought. We provide a timeline for the First Dynasty of Egypt of generational-scale resolution that concurs with prevailing archaeological analysis and produce a chronometric date for the foundation of Egypt that distinguishes between historical estimates.


2020 ◽  
Author(s):  
Fernando Gonçalves ◽  
Marcelo Magioli ◽  
Ricardo S. Bovendorp ◽  
Katia Maria Paschoaletto Micchi de Barros Ferraz ◽  
Letícia Bulascoschi Cagnoni ◽  
...  

AbstractThe proliferation of native, alien, invasive and domestic species provide novel and abundant food resources for the common vampire bat (Desmodus rotundus) that could alter its prey preference. Based on the analysis of carbon and nitrogen stable isotopes, we report the prey choice of D. rotundus on introduced mammals in an tropical land-bridge island where the domestic animals were removed and 100 individuals of 15 mammal species were intentionally introduced. Our analysis shows that, D. rotundus on Anchieta Island were more likely to prey upon species from open habitats (mean value of −14.8‰), i.e., animals with high δ13C values characterized by the consumption of C4 resources. As expected for a top predator species, δ15N values for D. rotundus were higher (mean value of 8.2‰) and overlapped the niche of the capybaras (Hydrochoerus hydrochaeris) from the Anchieta Island, while it was distant from coatis, and also from those potential prey from the preserved area in the mainland, including the capybaras, indicating that among all potential mammalian prey species, they fed exclusively on capybaras, the highest mammalian biomass on island. Based on previous information on human occupation, the domestic animals present on Anchieta island might be the main prey of D. rotundus and responsible for maintaining a viable population. As the capybaras were introduced only 36 years ago, this suggests a rapid prey shift due to anthropogenic disturbances, which has allowed common vampire bats to successfully exploit them. Literature records also show that common vampire bats were not captured in preserved areas of the mainland which are near Anchieta Island indicating that the percentage of capture of D. rotundus is usually low in natural forested habitats where potential prey are scattered. As three individuals of introduced capybaras were confirmed died from bat rabies viruses (RABV) in 2020, we suggest periodic monitoring of bat rabies viruses in common vampire bat populations on Anchieta Island and areas nearby, in order to quantify the magnitude of the outbreak area and develop strategies for controlling, especially considering that the island and areas nearby is frequently visited by tourists. We highlighted that this prey choice is context-dependent, and possibly influenced by the removal of domestic animals, the explosive population growth of introduced capybaras combined with their predictable foraging behavior.


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Liang Tian ◽  
Juping Zhang

In order to study the transmission of rabies epidemics in vampire bats, we propose a mathematical model for vampire bat rabies virus. A threshold R0 is identified which determines the outcome of the disease. If R0<1, the disease-free equilibrium is globally asymptotically stable, and if R0>1, the endemic equilibrium is globally asymptotically stable with certain conditions. Through the numerical simulation, the correctness of the theoretical results is verified. We carry out the sensitivity analysis of the parameters which provide a theoretical basis for preventing and controlling the transmission of bat rabies.


2020 ◽  
Author(s):  
Daniel J. Becker ◽  
Alice Broos ◽  
Laura M. Bergner ◽  
Diana K. Meza ◽  
Nancy B. Simmons ◽  
...  

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


Proceedings ◽  
2019 ◽  
Vol 30 (1) ◽  
pp. 9
Author(s):  
Sebastiano Trevisani

Modern Earth Scientists need also to interact with other disciplines, apparently far from the Earth Sciences and Engineering. Disciplines related to history and philosophy of science are emblematic from this perspective. From one side, the quantitative analysis of information extracted from historical records (documents, maps, paintings, etc.) represents an exciting research topic, requiring a truly holistic approach. On the other side, epistemological and philosophy of science considerations on the relationship between geoscience and society in history are of fundamental importance for understanding past, present and future geosphere-anthroposphere interlinked dynamics.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christopher Mark Joll

Abstract This article explores how scholarship can be put to work by specialists penning evidence-based policies seeking peaceful resolutions to long-standing, complex, and so-far intractable conflict in the Malay-Muslim dominated provinces of South Thailand. I contend that more is required than mere empirical data, and that the existing analysis of this conflict often lacks theoretical ballast and overlooks the wider historical context in which Bangkok pursued policies impacting its ethnolinguistically, and ethnoreligiously diverse citizens. I demonstrate the utility of both interacting with what social theorists have written about what “religion” and language do—and do not—have in common, and the relative importance of both in sub-national conflicts, and comparative historical analysis. The case studies that this article critically introduces compare chapters of ethnolinguistic and ethnoreligious chauvinism against a range of minorities, including Malay-Muslim citizens concentrated in the southern provinces of Pattani, Yala, and Narathiwat. These include Buddhist ethnolinguistic minorities in Thailand’s Northeast, and Catholic communities during the second world war widely referred to as the high tide of Thai ethno-nationalism. I argue that these revealing aspects of the southern Malay experience need to be contextualized—even de-exceptionalized.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mario Vallejo-Marín ◽  
Jannice Friedman ◽  
Alex D. Twyford ◽  
Olivier Lepais ◽  
Stefanie M. Ickert-Bond ◽  
...  

AbstractImperfect historical records and complex demographic histories present challenges for reconstructing the history of biological invasions. Here, we combine historical records, extensive worldwide and genome-wide sampling, and demographic analyses to investigate the global invasion of Mimulus guttatus from North America to Europe and the Southwest Pacific. By sampling 521 plants from 158 native and introduced populations genotyped at >44,000 loci, we determined that invasive M. guttatus was first likely introduced to the British Isles from the Aleutian Islands (Alaska), followed by admixture from multiple parts of the native range. We hypothesise that populations in the British Isles then served as a bridgehead for vanguard invasions worldwide. Our results emphasise the highly admixed nature of introduced M. guttatus and demonstrate the potential of introduced populations to serve as sources of secondary admixture, producing novel hybrids. Unravelling the history of biological invasions provides a starting point to understand how invasive populations adapt to novel environments.


2014 ◽  
Vol 281 (1788) ◽  
pp. 20141079 ◽  
Author(s):  
Wei Hong ◽  
Huabin Zhao

The bitter taste serves as an important natural defence against the ingestion of poisonous foods and is thus believed to be indispensable in animals. However, vampire bats are obligate blood feeders that show a reduced behavioural response towards bitter-tasting compounds. To test whether bitter taste receptor genes ( T2R s) have been relaxed from selective constraint in vampire bats, we sampled all three vampire bat species and 11 non-vampire bats, and sequenced nine one-to-one orthologous T2R s that are assumed to be functionally conserved in all bats. We generated 85 T2R sequences and found that vampire bats have a significantly greater percentage of pseudogenes than other bats. These results strongly suggest a relaxation of selective constraint and a reduction of bitter taste function in vampire bats. We also found that vampire bats retain many intact T2R s, and that the taste signalling pathway gene Calhm1 remains complete and intact with strong functional constraint. These results suggest the presence of some bitter taste function in vampire bats, although it is not likely to play a major role in food selection. Together, our study suggests that the evolutionary reduction of bitter taste function in animals is more pervasive than previously believed, and highlights the importance of extra-oral functions of taste receptor genes.


2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Anne Lavergne ◽  
Edith Darcissac ◽  
Hervé Bourhy ◽  
Sourakhata Tirera ◽  
Benoît de Thoisy ◽  
...  

A rabies virus was detected in a common vampire bat ( Desmodus rotundus ) in French Guiana. Its genomic sequence was obtained and found to be closely related to other hematophagous bat-related viruses that widely circulate in the northern Amazon region. This virus is named AT6.


Sign in / Sign up

Export Citation Format

Share Document