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Recrudescent infection supports Hendra virus persistence in Australian flying-fox populations.

Wang HH, Kung NY, Grant WE, Scanlan JC, Field HE - PLoS ONE (2013)

Bottom Line: Simulated infection patterns agree with infection patterns observed in the field and suggest that Hendra virus could be maintained in an isolated flying-fox population indefinitely via periodic recrudescence in a manner indistinguishable from maintenance via periodic immigration of infected individuals.Further, post-recrudescence pulses of infectious flying-foxes provide a plausible basis for the observed seasonal clustering of equine cases.Correct understanding of the infection dynamics of Hendra virus in flying-foxes is fundamental to effectively managing risk of infection in horses and humans.

View Article: PubMed Central - PubMed

Affiliation: Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, Texas, United States of America.

ABSTRACT
Zoonoses from wildlife threaten global public health. Hendra virus is one of several zoonotic viral diseases that have recently emerged from Pteropus species fruit-bats (flying-foxes). Most hypotheses regarding persistence of Hendra virus within flying-fox populations emphasize horizontal transmission within local populations (colonies) via urine and other secretions, and transmission among colonies via migration. As an alternative hypothesis, we explore the role of recrudescence in persistence of Hendra virus in flying-fox populations via computer simulation using a model that integrates published information on the ecology of flying-foxes, and the ecology and epidemiology of Hendra virus. Simulated infection patterns agree with infection patterns observed in the field and suggest that Hendra virus could be maintained in an isolated flying-fox population indefinitely via periodic recrudescence in a manner indistinguishable from maintenance via periodic immigration of infected individuals. Further, post-recrudescence pulses of infectious flying-foxes provide a plausible basis for the observed seasonal clustering of equine cases. Correct understanding of the infection dynamics of Hendra virus in flying-foxes is fundamental to effectively managing risk of infection in horses and humans. Given the lack of clear empirical evidence on how the virus is maintained within populations, the role of recrudescence merits increased attention.

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Related in: MedlinePlus

Conceptual model of the possible role of recrudescence in the persistence of Hendra virus in isolated flying-fox populations representing the daily dynamics of a colony consisting of (A) the various life history stages (pups, P; juveniles, J; pre-reproductive sub-adults, SA; reproductively mature adults, A), and (B) the various disease stages (maternally immune young-of-the-year, Mi; susceptible, S; exposed and latently infected, E; infectious, I; and recovered, R) individuals.
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pone-0080430-g001: Conceptual model of the possible role of recrudescence in the persistence of Hendra virus in isolated flying-fox populations representing the daily dynamics of a colony consisting of (A) the various life history stages (pups, P; juveniles, J; pre-reproductive sub-adults, SA; reproductively mature adults, A), and (B) the various disease stages (maternally immune young-of-the-year, Mi; susceptible, S; exposed and latently infected, E; infectious, I; and recovered, R) individuals.

Mentions: We formulated the model as an individual-based model representing the daily dynamics of a hypothetical black- (Pteropus alecto) or grey-headed (Pteropus poliocephalus) flying-fox population consisting of a single isolated colony. The colony is made up of male and female pups, juveniles, pre-reproductive sub-adults, and reproductively mature adults (Fig. 1A). Individuals also are classified as maternally immune (to Hendra) young-of-the-year, susceptible, exposed and latently infected, infectious, and recovered (immune but potentially recrudescent) (Fig. 1B). We assumed an initial colony size of 10,000 individuals [10] distributed among the various life history stages such as to be representative of a colony in dynamic equilibrium. That is, representative of a colony whose size varied seasonally and (stochastically) from year to year but with annual peaks remaining close to 10,000.


Recrudescent infection supports Hendra virus persistence in Australian flying-fox populations.

Wang HH, Kung NY, Grant WE, Scanlan JC, Field HE - PLoS ONE (2013)

Conceptual model of the possible role of recrudescence in the persistence of Hendra virus in isolated flying-fox populations representing the daily dynamics of a colony consisting of (A) the various life history stages (pups, P; juveniles, J; pre-reproductive sub-adults, SA; reproductively mature adults, A), and (B) the various disease stages (maternally immune young-of-the-year, Mi; susceptible, S; exposed and latently infected, E; infectious, I; and recovered, R) individuals.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3842926&req=5

pone-0080430-g001: Conceptual model of the possible role of recrudescence in the persistence of Hendra virus in isolated flying-fox populations representing the daily dynamics of a colony consisting of (A) the various life history stages (pups, P; juveniles, J; pre-reproductive sub-adults, SA; reproductively mature adults, A), and (B) the various disease stages (maternally immune young-of-the-year, Mi; susceptible, S; exposed and latently infected, E; infectious, I; and recovered, R) individuals.
Mentions: We formulated the model as an individual-based model representing the daily dynamics of a hypothetical black- (Pteropus alecto) or grey-headed (Pteropus poliocephalus) flying-fox population consisting of a single isolated colony. The colony is made up of male and female pups, juveniles, pre-reproductive sub-adults, and reproductively mature adults (Fig. 1A). Individuals also are classified as maternally immune (to Hendra) young-of-the-year, susceptible, exposed and latently infected, infectious, and recovered (immune but potentially recrudescent) (Fig. 1B). We assumed an initial colony size of 10,000 individuals [10] distributed among the various life history stages such as to be representative of a colony in dynamic equilibrium. That is, representative of a colony whose size varied seasonally and (stochastically) from year to year but with annual peaks remaining close to 10,000.

Bottom Line: Simulated infection patterns agree with infection patterns observed in the field and suggest that Hendra virus could be maintained in an isolated flying-fox population indefinitely via periodic recrudescence in a manner indistinguishable from maintenance via periodic immigration of infected individuals.Further, post-recrudescence pulses of infectious flying-foxes provide a plausible basis for the observed seasonal clustering of equine cases.Correct understanding of the infection dynamics of Hendra virus in flying-foxes is fundamental to effectively managing risk of infection in horses and humans.

View Article: PubMed Central - PubMed

Affiliation: Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, Texas, United States of America.

ABSTRACT
Zoonoses from wildlife threaten global public health. Hendra virus is one of several zoonotic viral diseases that have recently emerged from Pteropus species fruit-bats (flying-foxes). Most hypotheses regarding persistence of Hendra virus within flying-fox populations emphasize horizontal transmission within local populations (colonies) via urine and other secretions, and transmission among colonies via migration. As an alternative hypothesis, we explore the role of recrudescence in persistence of Hendra virus in flying-fox populations via computer simulation using a model that integrates published information on the ecology of flying-foxes, and the ecology and epidemiology of Hendra virus. Simulated infection patterns agree with infection patterns observed in the field and suggest that Hendra virus could be maintained in an isolated flying-fox population indefinitely via periodic recrudescence in a manner indistinguishable from maintenance via periodic immigration of infected individuals. Further, post-recrudescence pulses of infectious flying-foxes provide a plausible basis for the observed seasonal clustering of equine cases. Correct understanding of the infection dynamics of Hendra virus in flying-foxes is fundamental to effectively managing risk of infection in horses and humans. Given the lack of clear empirical evidence on how the virus is maintained within populations, the role of recrudescence merits increased attention.

Show MeSH
Related in: MedlinePlus