Attention:The NSF Public Access Repository (PAR) system and access will be unavailable from 11:00 PM ET on Thursday, October 15th until 12:00 AM ET on Friday, October 16th due to maintenance. We apologize for the inconvenience.


Title: Social effects of rabies infection in male vampire bats ( Desmodus rotundus )
Rabies virus (RABV) transmitted by the common vampire bat ( Desmodus rotundus ) poses a threat to agricultural development and public health throughout the Neotropics. The ecology and evolution of rabies host–pathogen dynamics are influenced by two infection-induced behavioural changes. RABV-infected hosts often exhibit increased aggression which facilitates transmission, and rabies also leads to reduced activity and paralysis prior to death. Although several studies document rabies-induced behavioural changes in rodents and other dead-end hosts, surprisingly few studies have measured these changes in vampire bats, the key natural reservoir throughout Latin America. Taking advantage of an experiment designed to test an oral rabies vaccine in captive male vampire bats, we quantify for the first time, to our knowledge, how rabies affects allogrooming and aggressive behaviours in this species. Compared to non-rabid vampire bats, rabid individuals reduced their allogrooming prior to death, but we did not detect increases in aggression among bats. To put our results in context, we review what is known and what remains unclear about behavioural changes of rabid vampire bats (resumen en español, electronic supplementary material, S1).  more » « less
Award ID(s):
2015928
PAR ID:
10385953
Author(s) / Creator(s):
; ; ; ; ;
Date Published:
Journal Name:
Biology Letters
Volume:
18
Issue:
9
ISSN:
1744-957X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Davis, Amy J (Ed.)
    BackgroundRabies is an acute and progressive viral zoonotic disease of the nervous system, which widely affects domestic animals in Latin America. Vampire bat-borne rabies virus (RABV) has significant negative impacts on the livestock industry via animal mortality. Nevertheless, the landscape level factors that facilitate or limit RABV transmission from vampire bats to livestock remain elusive. MethodsTo determine how abiotic and biotic factors modulate RABV spillover from vampire bats to livestock, we assessed the role of different landscape variables on the occurrence of RABV spillover fromDesmodus rotundusto livestock in Colombia. Using ecological niche modeling as the theoretical and analytical framework, we analyzed ecological and epidemiological RABV data to reconstruct spillover transmission events. ResultsAnthropogenic variables including livestock and human density were consistently selected as predictors of RABV spillover from vampire bats to livestock. Cattle density had the highest average relative contribution to final ecological niche models (64.7%). We also found improvement of RABV spillover risk estimates when sampling bias in the form of cattle density was used in the modeling process. High risk for RABV spillover (0.75-0.98) was consistently predicted in the Caribbean region of Colombia. Nevertheless, more widespread moderate RABV spillover risk was predicted more broadly across the country when sampling bias was accounted for. ConclusionOur modelling effort revealed that variable selection and use of bias surface have tractable impacts on final projections of spillover risk. Our results also indicate that human activity drives RABV spillover risk to a greater extent than ecological or climatological factors. Results from this study provide important information about landscape conditions linked to RABV transmission risk, where livestock vaccination should be prioritized. 
    more » « less
  2. Abstract BackgroundRabies virus (RABV) is the etiologic agent of rabies, a fatal brain disease in mammals. Rabies circulation has historically involved the dog has the main source of human rabies worldwide. Nevertheless, in Colombia, cats (Felis catus) have become a relevant species in the epidemiology of rabies. AimsTo characterize rabies cases in humans in Colombia in the last three decades in the context of the epidemiology of the aggressor animal. Materials and MethodsWe conducted a retrospective longitudinal epidemiological study of human rabies caused by cats’ aggression, collecting primary and secondary information. Variables considered included the demography of the patient, symptoms, information about the aggressor animal as the source of infection and the viral variant identified. ResultsWe found that the distribution of rabies incidence over the years has been constant in Colombia. Nevertheless, between 2003 and 2012 a peak of cases occurred in rural Colombia where cats were the most frequent aggressor animal reported. Most cats involved in aggression were unvaccinated against rabies. Cat's clinical signs at the time of the report of the human cases included hypersalivation and changes in behaviour. Human patients were mostly children and female and the exposure primarily corresponded to bite and puncture lacerations in hands. The RABV lineage detected in most cases corresponded to variant 3, linked to the common vampire bat (Desmodus rotundus). The geographical presentation of cat borne RABV in humans occurred along the Andes mountains, epidemiologically known as the rabies red Andean corridor. DiscussionBy finding cats as the primary source of rabies spillover transmission in Colombia, this report highlights the importance of revising national rabies control and prevention protocol in countries in the Andes region. ConclusionOur results demonstrate that rabies vaccination for outdoor cats needs to prioritize to reduce the number of rabies‐related human deaths. 
    more » « less
  3. Abstract Pathogen 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. 
    more » « less
  4. Individual animals across many different species occasionally ‘adopt’ unrelated, orphaned offspring. Although adoption may be best explained as a by-product of adaptive traits that enhance parental care or promote the development of parental skills, one factor that is possibly important for the likelihood of adoption is the history of cooperative interactions between the mother, adopted offspring and adopter. Using 652 h of behavioural samples collected over four months, we describe patterns of allogrooming and food sharing before and after an instance of non-kin adoption between two adult female common vampire bats ( Desmodus rotundus ) that were captured from distant sites (340 km apart) and introduced to one another in captivity. The first female died from an illness 19 days after giving birth. The second female groomed and regurgitated food to the mother more often than any other group member, then groomed, nursed and regurgitated food to the orphaned, female pup. The substantial increase in alloparental care by this female after the mother's death was not observed among the 20 other adult females that were present in the colony. Our findings corroborate previous reports of non-kin adoption in common vampire bats and are consistent with the hypothesis that non-kin adoption can be motivated, in part, by a history of cooperative interactions. 
    more » « less
  5. Abstract In Latin America, management of vampire bats has had inconsistent effects on the spread of lethal rabies infections from bats to humans and livestock. Positive and negative effects on rabies are hypothesised to reflect changes in bat roost fidelity and behaviour following human disturbance, but high landscape complexity has precluded monitoring bat movement in the areas where rabies transmission and bat management activity are most prevalent. We used animal-borne GPS tags to track 93 vampire bats in a rabies hotspot in the Peruvian Andes, where limited satellite visibility led to partial observation of animal locations. Immediately after capture, handling and tag application, 43% of bats, particularly males and bats with longer forearms, disappeared from the study area, suggesting a rapid roost switching response. Among the remaining 55 bats, a Bayesian state-space model revealed high individual heterogeneity on the disturbance night but on average increased flight distances. Over the remaining 8-night study period, bats gradually remained closer to the roost. These disturbance-driven shifts provide mechanisms to explain how bat disturbance can both accelerate and decelerate rabies spatial spread. More broadly, we present a modelling framework to infer key movement metrics in landscapes where GPS data limitations challenge conventional movement models. 
    more » « less