Waterbird movement across the Great Dividing Range and implications for arbovirus irruption into southern Victoria

Background Waterbirds are the major hosts of various arboviruses. Murray Valley encephalitis virus (MVEV) is an arbovirus native to northern Australia, the major hosts of which are Phalacrocoraciformes (cormorants), Ciconiiformes (herons) and other waterbirds. MVEV is transmitted to humans by mosquitoes and can cause acute encephalomyelitis. In Victoria, MVEV is restricted to the northern side of the Great Dividing Range (GDR), suggesting that waterbirds cannot cross the high country. Methods and results We tested this hypothesis by analysing data on waterbird banding and recovery and discovered that 12 species can cross the GDR. Conclusion Waterbirds have the potential to carry arboviruses, including MVEV, into southern Victoria.