Ms Polly Hannaford1,2,3, Dr Nick Moody1, Dr David Cummins1, Stacey Valdeter1, Dr Peter Mohr1, Dr Kostlend Mara1, Harley England1, Dr John Hoad1, Professor Robert Lanfear2, Dr Jeffrey Go4, Dr Robyn Hall5, Maddie Reynolds1
1CSIRO Australian Centre for Disease Preparedness, Geelong, Australia, 2Australian National University , Canberra, Australia, 3Australian Department of Agriculture, Fisheries and Forestry, Canberra, Australia, 4Department of Primary Industries and Regional Development, Sydney, Australia, 5ViroEpiVet, , Australia
Biography:
Polly has worked for the Australian Public Service in the agriculture and environment portfolios. Working at the intersection between science and public policy, she has led the development of biosecurity policies and international trade negotiations to reduce aquatic animal disease risk to Australia. Polly received first class honours from The University of Sydney in 2018 in animal science. She joined the Australian Department of Agriculture, Fisheries and Forestry as a graduate in 2019 whilst continuing her education at the Australian National University studying science, technology and public policy. Polly was awarded a Sir Roland Wilson PhD scholarship in 2024 and is currently on secondment from public-service life, researching ways to improve Australia’s aquatic animal pathogen detection capability.
Abstract:
Megalocytiviruses are among the most serious viral pathogens threatening aquaculture and aquatic environments. This study aims to design a passive environmental DNA (eDNA) test method for the quick, inexpensive and reliable surveillance of megalocytiviruses. Passive eDNA sampling is less labour-intensive than active eDNA sampling and works by deploying a passive eDNA sampling material (PED) in situ to accumulate eDNA over time. Here, the effectiveness of eight PEDs were compared for capturing Megalocytivirus eDNA in water. The PEDs were submerged in tanks with infectious Megalocytivirus at four concentrations: T1 'Moderate', T2 'Low', T3 'Very low', and T4 'Extremely Low'. Each treatment group had two replicates. A control group (T5) had no virus added. The PEDs were sampled at timepoints spanning 0.5hrs- to 72hrs-post submersion. For comparison, an active eDNA sample was taken at each time point. All samples were tested by quantitative PCR. The absorption efficiency of PEDs increased with increases in submersion time, reaching a maximum at 24hrs or 48hrs before declining. The ISKNV eDNA concentration detected through active eDNA sampling decreased over time. A zeolite-embedded PED consistently demonstrated the best eDNA absorption efficiency of the PEDs trialled. This study demonstrated the potential of passive eDNA sampling as a tool for the detection of fish viruses in water for use by industry and government. An in vivo experiment completed in July 2026 tested the ability of zeolite-embedded PEDs in capturing Megalocytivirus shed from live infected fish. The results of the in vivo experiment will be ready to present in February.