title: Avian influenza infection dynamics under variable climatic conditions, viral prevalence is rainfall driven in waterfowl from temperate, south-east Australia.
abstract: Understanding Avian Influenza Virus (AIV) infection dynamics in wildlife is crucial because of possible virus spill over to livestock and humans. Studies from the northern hemisphere have suggested several ecological and environmental drivers of AIV prevalence in wild birds. To determine if the same drivers apply in the southern hemisphere, where more irregular environmental conditions prevail, we investigated AIV prevalence in ducks in relation to biotic and abiotic factors in south-eastern Australia. We sampled duck faeces for AIV and tested for an effect of bird numbers, rainfall anomaly, temperature anomaly and long-term ENSO (El-Niño Southern Oscillation) patterns on AIV prevalence. We demonstrate a positive long term effect of ENSO-related rainfall on AIV prevalence. We also found a more immediate response to rainfall where AIV prevalence was positively related to rainfall in the preceding 3-7 months. Additionally, for one duck species we found a positive relationship between their numbers and AIV prevalence, while prevalence was negatively or not affected by duck numbers in the remaining four species studied. In Australia largely non-seasonal rainfall patterns determine breeding opportunities and thereby influence bird numbers. Based on our findings we suggest that rainfall influences age structures within populations, producing an influx of immunologically naïve juveniles within the population, which may subsequently affect AIV infection dynamics. Our study suggests that drivers of AIV dynamics in the northern hemisphere do not have the same influence at our south-east Australian field site in the southern hemisphere due to more erratic climatological conditions.
authors: Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, VIC, 3220, Australia. mferencz@deakin.edu.au.
authors: Marta
authors: M
authors: Ferenczi
authors: Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, VIC, 3220, Australia. c.beckmann@deakin.edu.au.
authors: Christa
authors: C
authors: Beckmann
authors: Department of Economic Development, Jobs, Transport and Resources, Biosciences Research, AgriBio, Centre for AgriBiosciences, 5 Ring Road, Bundoora, VIC, 3083, Australia. Simone.Warner@ecodev.vic.gov.au.
authors: Simone
authors: S
authors: Warner
authors: Department of Sustainability and Environment, Arthur Rylah Institute for Environmental Research, Heidelberg, VIC, Australia. richard.loyn@bigpond.com.|Eco Insights, 4 Roderick Close, Viewbank, VIC, 3084, Australia. richard.loyn@bigpond.com.
authors: Richard
authors: R
authors: Loyn
authors: Department of Economic Development, Jobs, Transport and Resources, Biosciences Research, AgriBio, Centre for AgriBiosciences, 5 Ring Road, Bundoora, VIC, 3083, Australia. Kim.O'Riley@ecodev.vic.gov.au.
authors: Kim
authors: K
authors: O'Riley
authors: Department of Economic Development, Jobs, Transport and Resources, Biosciences Research, AgriBio, Centre for AgriBiosciences, 5 Ring Road, Bundoora, VIC, 3083, Australia. Xinlong.Wang@ecodev.vic.gov.au.
authors: Xinlong
authors: X
authors: Wang
authors: Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, VIC, 3220, Australia. marcel.klaassen@deakin.edu.au.
authors: Marcel
authors: M
authors: Klaassen
mesh_terms: D000818:Animals; D000835:Animals, Wild; D004372:Ducks; D005243:Feces / Q000821:virology; D009980:Influenza A virus / Q000502:physiology*; D005585:Influenza in Birds / Q000453:epidemiology* / Q000821:virology; D011156:Population Density; D015995:Prevalence; D011891:Rain; D012621:Seasons; D014739:Victoria / Q000453:epidemiology