Informing surveillance and response to arboviruses in Australia
Project Details
Supporting the national JEV outbreak response (2022–23)
Japanese encephalitis virus (JEV) is a mosquito-borne, zoonotic virus endemic to Asia and the Western Pacific that circulates primarily between mosquitoes, ardeid birds and swine. Spillover infections in humans cause Japanese encephalitis (JE) disease, which can result in serious and fatal illness.JEV is the leading cause of viral encephalitis in humans globally.Infections of JEV have been sporadically detected in Australia's tropical northern extreme in the Torres Strait since 1995, but in early 2022 was detected in the temperate southern states of Victoria and South Australia, a latitudinal expansion of more than 3,000km. By the end of autumn 2022, an unprecedented 45 cases of JE had been diagnosed in humans in Australia, including seven deaths, with many more detections in feral pigs and commercial piggeries.
JEV is a novel disease ecosystem in temperate Australia and the ecology of transmission is poorly known. In March 2022, a Communicable Disease Incident of National Significance was declared. Both despite and because of the uncertainty in the new transmission dynamics, there was a need to rapidly understand the potential infection risk to humans and domestic animals to support the efficient targeting of surveillance resources and interventions.
Our team conducted a geospatial assessment of JEV transmission risk to highlight areas where health departments could prioritise surveillance for the virus and distribution of Australia’s stocks of the JEV vaccine. We developed geospatial models to predict where in Australia the habitat might be suitable for the combinations of mosquito and waterbird species thought to be involved in transmission. The team also developed models to estimate the spatial extent of disease transmission during the outbreak and areas at future risk of transmission. Our work incorporated data on environmental conditions, the occurrence of host and vector species, and JEV screening of mosquitoes, domestic and feral pigs, and sentinel chicken flocks from Australian states and territories. Our analysis synthesised for health departments an understanding of where in Australia JEV poses the greatest risk to humans, enabling them to better respond and protect Australians from this emerging disease.
Towards integrated arbovirus surveillance, modelling, and forecasting
Our JEV work presented an opportunity to address critical knowledge gaps in arbovirus vector distributions and vector population dynamics that limit our capacity to respond to changing disease landscapes. We are undertaking a program of work to integrate modelling with entomological surveillance to rapidly and robustly fill these knowledge gaps, thereby enabling public health practitioners to establish surveillance networks which are optimal for routine monitoring, early warning systems, and readily adaptable to emergency response and changing environmental conditions.
Researchers
Prof Nick Golding
Ms Lucy Harrison​
Collaborators
Funding
Australian Government Department of Health and Aged Care
Research Outcomes
Duncan, D.H., Harrison, L., Germano, D., Flegg, J., Price, D.J., McCaw, J., Golding, N., & Shearer, F.M.
(2023) Mapping Japanese encephalitis virus infection risk in Australia: Phase 2 Final Report. Unpublished Report to the Australian Commonwealth Government Department of Health and Aged Care.
Harrison, L., Duncan D.H., Flegg, J., Price, D.J., McCaw, J., Golding, N., & Shearer, F.M. (2022). Mapping Japanese encephalitis infection risk in Australia to inform public health response. Unpublished report to the Australian Commonwealth Government Department of Health and Aged Care.