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Spatial expansions and travelling waves of rabies in vampire bats

View Article: PubMed Central

ABSTRACT

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.

No MeSH data available.


National spatial expansion of VBR. Annual (main figure) and cumulative (inset figure) number of governmental districts reporting VBR outbreaks from 2003 until 2014. Lines show values predicted by the loess function in R.
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RSPB20160328F2: National spatial expansion of VBR. Annual (main figure) and cumulative (inset figure) number of governmental districts reporting VBR outbreaks from 2003 until 2014. Lines show values predicted by the loess function in R.

Mentions: The national increase in rabies outbreaks occurred concurrently with spatial expansions into historically uninfected areas. The cumulative number of districts with confirmed cases more than tripled between 2003 and 2014, such that on average VBR spread into 12 (standard deviation, s.d. = 0.319) previously uninfected districts per year (figure 2, inset), a pattern also observed at the monthly level (1 district month−1, s.d. = 0.007). The number of infected districts also increased in annual (non-cumulative) reports, with most dramatic spatial expansions coinciding with the increase in outbreaks following 2011 (figures 1b,2). Hotspots of spatial expansion occurred in the regions of San Martin, Amazonas and Cajamarca in the north of Peru (5.2 districts yr−1, s.d. = 0.36) and in Apurimac, Ayacucho and Cusco in the south (4.1 districts yr−1, s.d. = 0.12). By contrast, few new districts were infected in the Amazonian regions of Loreto, Ucayali and Madre de Dios (1.4 districts yr−1, s.d. = 0.21), where no new districts were infected in the last 3 years. Consistent with epizootic spatial expansions from enzootic zones, 85% of newly infected districts had a neighbouring district infected in the same or previous year.Figure 2.


Spatial expansions and travelling waves of rabies in vampire bats
National spatial expansion of VBR. Annual (main figure) and cumulative (inset figure) number of governmental districts reporting VBR outbreaks from 2003 until 2014. Lines show values predicted by the loess function in R.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC4920313&req=5

RSPB20160328F2: National spatial expansion of VBR. Annual (main figure) and cumulative (inset figure) number of governmental districts reporting VBR outbreaks from 2003 until 2014. Lines show values predicted by the loess function in R.
Mentions: The national increase in rabies outbreaks occurred concurrently with spatial expansions into historically uninfected areas. The cumulative number of districts with confirmed cases more than tripled between 2003 and 2014, such that on average VBR spread into 12 (standard deviation, s.d. = 0.319) previously uninfected districts per year (figure 2, inset), a pattern also observed at the monthly level (1 district month−1, s.d. = 0.007). The number of infected districts also increased in annual (non-cumulative) reports, with most dramatic spatial expansions coinciding with the increase in outbreaks following 2011 (figures 1b,2). Hotspots of spatial expansion occurred in the regions of San Martin, Amazonas and Cajamarca in the north of Peru (5.2 districts yr−1, s.d. = 0.36) and in Apurimac, Ayacucho and Cusco in the south (4.1 districts yr−1, s.d. = 0.12). By contrast, few new districts were infected in the Amazonian regions of Loreto, Ucayali and Madre de Dios (1.4 districts yr−1, s.d. = 0.21), where no new districts were infected in the last 3 years. Consistent with epizootic spatial expansions from enzootic zones, 85% of newly infected districts had a neighbouring district infected in the same or previous year.Figure 2.

View Article: PubMed Central

ABSTRACT

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.

No MeSH data available.