William Valderrama

Dr. William Valderrama

UAB

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 June 2012 in Proceedings Of The Royal Society B-Biological Sciences
Verified
Journal Article
Closed access
DSDaniel Streicker
Daniel Streicker
SRSergio Recuenco
Sergio Recuenco
WVWilliam Valderrama
William Valderrama
JBJorge Gomez Benavides
Jorge Gomez Benavides
IVIvan Vargas
Ivan Vargas
SASonia Altizer
Sonia Altizer
Despite extensive culling of common vampire bats in Latin America, lethal human rabies outbreaks transmitted by this species are increasingly recognized, and livestock rabies occurs with striking frequency. To identify the individual and population-level factors driving rabies virus (RV) transmission in vampire bats, we conducted a longitudinal capture–recapture study in 20 vampire bat colonies spanning four regions of Peru. Serology demonstrated the circulation of RV in vampire bats from all regions in all years. Seroprevalence ranged from 3 to 28 per cent and was highest in juvenile and sub-adult bats. RV exposure was independent of bat colony size, consistent with an absence of population density thresholds for viral invasion and extinction. Culling campaigns implemented during our study failed to reduce seroprevalence and were perhaps counterproductive for disease control owing to the targeted removal of adults, but potentially greater importance of juvenile and sub-adult bats for transmission. These findings provide new insights into the mechanisms of RV maintenance in vampire bats and highlight the need for ecologically informed approaches to rabies prevention in Latin America.

12 September 2016 in Proceedings of the National Academy of Sciences
Verified
Journal Article
Closed access
PDF file
DSDaniel Streicker
Daniel Streicker
JWJamie C. Winternitz
Jamie C. Winternitz
DSDara A. Satterfield
Dara A. Satterfield
RCRene Edgar Condori-Condori
Rene Edgar Condori-Condori
ABAlice Broos
Alice Broos
WVWilliam Valderrama
William Valderrama
Significance: In Latin America, vampire bat rabies constrains livestock production and is the main cause of lethal human rabies outbreaks. Despite knowledge that bat dispersal prevents viral extinction and compromises control campaigns, the movement patterns of infected bats are unknown. Using large host and virus datasets, we illustrate a genetic approach to link population level patterns of host dispersal to pathogen spatial spread that overcomes logistical limitations of tracking animal movement in the wild. The results implicate male vampire bats as contributing disproportionately to rabies spatial spread and offer opportunities to forecast and prevent rabies. The ubiquity of sex-biased dispersal in animals suggests sex-biased pathogen spread could widely influence the distribution and invasion dynamics of emerging diseases.

8 September 2020 in Viruses
Verified
Journal Article
Open access
PDF file
JBJulio Benavides
Julio Benavides
WVWilliam Valderrama
William Valderrama
SRSergio Recuenco
Sergio Recuenco
WUWilson Uieda
Wilson Uieda
GSGerardo Suzán
Gerardo Suzán
DSDaniel Streicker
Daniel Streicker
Rabies transmitted by common vampire bats (Desmodus rotundus) has been known since the early 1900s but continues to expand geographically and in the range of species and environments affected. In this review, we present current knowledge of the epidemiology and management of rabies in D. rotundus and argue that it can be reasonably considered an emerging public health threat. We identify knowledge gaps related to the landscape determinants of the bat reservoir, reduction in bites on humans and livestock, and social barriers to prevention. We discuss how new technologies including autonomously-spreading vaccines and reproductive suppressants targeting bats might manage both rabies and undesirable growth of D. rotundus populations. Finally, we highlight widespread under-reporting of human and animal mortality and the scarcity of studies that quantify the efficacy of control measures such as bat culling. Collaborations between researchers and managers will be crucial to implement the next generation of rabies management in Latin America.

15 June 2016 in Proceedings Of The Royal Society B-Biological Sciences
Verified
Journal Article
Open access
JBJulio Benavides
Julio Benavides
WVWilliam Valderrama
William Valderrama
DSDaniel Streicker
Daniel Streicker
A major obstacle to anticipating the cross-species transmission of zoonotic diseases and developing novel strategies for their control is the scarcity of data informing how these pathogens circulate within natural reservoir populations. Vampire bats are the primary reservoir of rabies in Latin America, where the disease remains among the most important viral zoonoses affecting humans and livestock. Unpredictable spatiotemporal dynamics of rabies within bat populations have precluded anticipation of outbreaks and undermined widespread bat culling programs. By analysing 1146 vampire bat-transmitted rabies (VBR) outbreaks in livestock across 12 years in Peru, we demonstrate that viral expansions into historically uninfected zones have doubled the recent burden of VBR. Viral expansions are geographically widespread, but severely constrained by high elevation peaks in the Andes mountains. Within Andean valleys, invasions form wavefronts that are advancing towards large, unvaccinated livestock populations that are heavily bitten by bats, which together will fuel high transmission and mortality. Using spatial models, we forecast the pathways of ongoing VBR epizootics across heterogeneous landscapes. These results directly inform vaccination strategies to mitigate impending viral emergence, reveal VBR as an emerging rather than an enzootic disease and create opportunities to test novel interventions to manage viruses in bat reservoirs.

21 December 2017 in PLOS Neglected Tropical Diseases
Verified
Journal Article
Open access
PDF file
JBJulio Benavides
Julio Benavides
EPElizabeth Rojas Paniagua
Elizabeth Rojas Paniagua
KHKatie Hampson
Katie Hampson
WVWilliam Valderrama
William Valderrama
DSDaniel G Streicker
Daniel G Streicker
Knowledge of infectious disease burden is necessary to appropriately allocate resources for prevention and control. In Latin America, rabies is among the most important zoonoses for human health and agriculture, but the burden of disease attributed to its main reservoir, the common vampire bat (Desmodus rotundus), remains uncertain. We used questionnaires to quantify under-reporting of livestock deaths across 40 agricultural communities with differing access to health resources and epidemiological histories of vampire bat rabies (VBR) in the regions of Apurimac, Ayacucho and Cusco in southern Peru. Farmers who believed VBR was absent from their communities were one third as likely to report livestock deaths from disease as those who believed VBR was present, and under-reporting increased with distance from reporting offices. Using generalized mixed-effect models that captured spatial autocorrelation in reporting, we project 4.6 (95% CI: 4.4–8.2) rabies cases per reported case and identify geographic areas with potentially greater VBR burden than indicated by official reports. Spatially-corrected models estimate 505–724 cattle deaths from VBR in our study area during 2014 (421–444 deaths/100,000 cattle), costing US$121,797–171,992. Cost benefit analysis favoured vaccinating all cattle over the current practice of partial vaccination or halting vaccination all together. Our study represents the first estimate of the burden of VBR in Latin America to incorporate data on reporting rates. We confirm the long-suspected cost of VBR to small-scale farmers and show that vaccinating livestock is a cost-effective solution to mitigate the burden of VBR. More generally, results highlight that ignoring geographic variation in access to health resources can bias estimates of disease burden and risk. The number of cases and monetary cost of a disease guides how resources for prevention and control are allocated. In Latin America, rabies transmitted by vampire bats is one of the most recognized zoonoses affecting humans and livestock, but its burden on lives and livelihoods has been difficult to calculate because the percentage of outbreaks that are not reported to surveillance systems is unknown. Here, using surveys to calculate farmers’ tendencies to report livestock deaths, we estimate that over 500 cattle died of rabies in southern Peru in 2014, a loss of approximately US$170,000 or over 700 months of local income. Our results also show that the perceived risk of rabies strongly affected reporting of cattle mortality and vaccination coverage, suggesting that campaigns to increase awareness could reduce the burden of rabies.

18 November 2019 in Nature Ecology & Evolution
Verified
Journal Article
Closed access
KBKevin Bakker
Kevin Bakker
TRTonie E. Rocke
Tonie E. Rocke
JOJorge E. Osorio
Jorge E. Osorio
RARachel C. Abbott
Rachel C. Abbott
CTCarlos Tello
Carlos Tello
DSDaniel Streicker
Daniel Streicker