eCite Digital Repository
Transmission dynamics of Tasmanian devil facial tumor disease may lead to disease-induced extinction
Citation
McCallum, HI and Jones, M and Hawkins, CE and Hamede Ross, RK and Lachish, S and Sinn, DL and Beeton, N and Lazenby, B, Transmission dynamics of Tasmanian devil facial tumor disease may lead to disease-induced extinction, Ecology, 90, (12) pp. 3379-3392. ISSN 0012-9658 (2009) [Refereed Article]
![]() | PDF Restricted - Request a copy 380Kb |
Copyright Statement
Copyright © 2009 by the Ecological Society of America
Official URL: http://www.esa.org/
Abstract
Most pathogens threatening to cause extinction of a host species are maintained
on one or more reservoir hosts, in addition to the species that is threatened by disease.
Further, most conventional host–pathogen theory assumes that transmission is related to host
density, and therefore a pathogen should become extinct before its sole host. Tasmanian devil
facial tumor disease is a recently emerged infectious cancer that has led to massive population
declines and grave concerns for the future persistence of this largest surviving marsupial
carnivore. Here we report the results of mark–recapture studies at six sites and use these data
to estimate epidemiological parameters critical to both accurately assessing the risk of
extinction from this disease and effectively managing this disease threat. Three sites were
monitored from before or close to the time of disease arrival, and at three others disease was
well established when trapping began, in one site for at least 10 years. We found no evidence
for sex-specific differences in disease prevalence and little evidence of consistent seasonal
variation in the force of infection. At all sites, the disease was maintained at high levels of
prevalence (>50% in 2–3-year-old animals), despite causing major population declines. We
also provide the first estimates of the basic reproductive rate R0 for this disease. Using a simple age-structured deterministic model, we show that our results are not consistent with
transmission being proportional to the density of infected hosts but are consistent with
frequency-dependent transmission. This conclusion is further supported by the observation
that local disease prevalence in 2–3-year-olds still exceeds 50% at a site where population
density has been reduced by up to 90% in the past 12 years. These findings lend considerable
weight to concerns that this host-specific pathogen will cause the extinction of the Tasmanian
devil. Our study highlights the importance of rapidly implementing monitoring programs to
determine how transmission depends on host density and emphasizes the need for ongoing
management strategies involving a disease-free "insurance population," along with ongoing
field monitoring programs to confirm whether local population extinction occurs.
Item Details
Item Type: | Refereed Article |
---|---|
Keywords: | basic reproductive number, R0, conservation biology, extinction, facial tumor disease, pathogen transmission, Sarcophilus harrisii, Tasmanian devil |
Research Division: | Biological Sciences |
Research Group: | Microbiology |
Research Field: | Microbial ecology |
Objective Division: | Environmental Management |
Objective Group: | Terrestrial systems and management |
Objective Field: | Control of pests, diseases and exotic species in terrestrial environments |
UTAS Author: | McCallum, HI (Professor Hamish McCallum) |
UTAS Author: | Jones, M (Professor Menna Jones) |
UTAS Author: | Hawkins, CE (Dr Clare Hawkins) |
UTAS Author: | Hamede Ross, RK (Dr Rodrigo Hamede Ross) |
UTAS Author: | Lachish, S (Ms Shelly Lachish) |
UTAS Author: | Sinn, DL (Dr David Sinn) |
UTAS Author: | Beeton, N (Dr Nicholas Beeton) |
ID Code: | 62173 |
Year Published: | 2009 |
Web of Science® Times Cited: | 161 |
Deposited By: | Zoology |
Deposited On: | 2010-03-10 |
Last Modified: | 2014-01-02 |
Downloads: | 7 View Download Statistics |
Repository Staff Only: item control page