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.

Risk of Buruli ulcer and detection of Mycobacterium ulcerans in mosquitoes in southeastern Australia.

Background: Buruli ulcer (BU) is a destructive skin condition caused by infection with the environmental bacterium, Mycobacterium ulcerans. The mode of transmission of M. ulcerans is not completely understood, but several studies have explored the role of biting insects.

Seroconversion to avian influenza virus in free-range chickens in the Riverland region of Victoria.

Background: Since 2005, H5N1 avian influenza (AI) has spread from South-East Asia to over 60 different countries, resulting in the direct death or slaughter of over 250,000,000 poultry. Migratory waterfowl have been implicated in this spread and in Australia there have been numerous isolations of low-pathogenicity AI virus from wild waterfowl and shorebirds. The Department of Human Services, Victoria maintains 10 sentinel free-range chicken flocks in the Riverland at locations that are populated by large numbers of waterfowl known to carry a range of strains of AI.

Mycolactone gene expression is controlled by strong SigA-like promoters with utility in studies of Mycobacterium ulcerans and buruli ulcer.

Mycolactone A/B is a lipophilic macrocyclic polyketide that is the primary virulence factor produced by Mycobacterium ulcerans, a human pathogen and the causative agent of Buruli ulcer. In M. ulcerans strain Agy99 the mycolactone polyketide synthase (PKS) locus spans a 120 kb region of a 174 kb megaplasmid.

Disease suspected to be caused by Ross River virus infection of horses.

Ross River Virus (RRV) was believed to be the cause of acute illness in four horses around the Bellarine peninsula in south-west Victoria, Australia. The horses presented with clinical signs including petechial haemorrhages, lymphadenopathy, distal limb swelling and reluctance to move. Fibrinogen was also elevated in three of the four horses.