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Disentangling synergistic disease dynamics: Implications for the viral biocontrol of rabbits

journal contribution
posted on 2023-05-20, 23:03 authored by Wells, K, Fordham, DA, Barry BrookBarry Brook, Cassey, P, Cox, T, O'Hara, RB, Schwensow, NI
  1. European rabbits (Oryctolagus cuniculus) have been exposed to rabbit haemorrhagic disease virus (RHDV) and myxoma virus (MYXV) in their native and invasive ranges for decades. Yet, the long‐term effects of these viruses on rabbit population dynamics remain poorly understood.
  2. In this context, we analysed 17 years of detailed capture–mark–recapture data (2000–2016) from Turretfield, South Australia, using a probabilistic state‐space hierarchical modelling framework to estimate rabbit survival and epidemiological dynamics.

  3. While RHDV infection and disease‐induced death were most prominent during annual epidemics in winter and spring, we found evidence for continuous infection of susceptible individuals with RHDV throughout the year. RHDV‐susceptible rabbits had, on average, 25% lower monthly survival rates compared to immune individuals, while the average monthly force of infection in winter and spring was ∼38%. These combined to result in an average infection‐induced mortality rate of 69% in winter and spring.
  4. Individuals susceptible to MYXV and immune to RHDV had similar survival probabilities to those having survived infections from both viruses, whereas individuals susceptible to both RHDV and MYXV had higher survival probabilities than those susceptible to RHDV and immune to MYXV. This suggests that MYXV may reduce the future survival rates of individuals that endure initial MYXV infection.
  5. There was no evidence for long‐term changes in disease‐induced mortality and infection rates for either RHDV or MYXV.
  6. We conclude that continuous, year‐round virus perpetuation (and perhaps heterogeneity in modes of transmission and infectious doses during and after epidemics) acts to reduce the efficiency of RHDV and MYXV as biocontrol agents of rabbits in their invasive range. However, if virulence can be maintained as relatively constant through time, RHDV and MYXV will likely continue realizing strong benefits as biocontrol agents.

Funding

Australian Research Council

History

Publication title

Journal of Animal Ecology

Volume

87

Issue

5

Pagination

1418-1428

ISSN

0021-8790

Department/School

School of Natural Sciences

Publisher

Blackwell Publishing Ltd

Place of publication

9600 Garsington Rd, Oxford, England, Oxon, Ox4 2Dg

Rights statement

© 2018 The Authors. Journal of Animal Ecology. © 2018 British Ecological Society

Repository Status

  • Restricted

Socio-economic Objectives

Control of pests, diseases and exotic species in terrestrial environments; Evaluation, allocation, and impacts of land use