Mosquitoes that spread the potentially deadly dengue and yellow fever viruses have been found at Melbourne Airport in what appears to be a serious breach of Australia's stringent quarantine system.
The discovery has sparked fears that colonies of the mosquitoes could be spreading into the surrounding environment and travelling interstate on passenger and cargo planes.
The same type of mosquitoes are also believed to have been found at airports in Adelaide and Perth.
Fairfax Media can reveal that bio-security officers from the Department of Agriculture discovered the mosquitoes during a routine inspection of the plastic, water-filled bollards used to manage traffic in and around the airport.
The mosquitoes were first detected in bollards inside the airport's baggage tunnels.
Health authorities have begun implementing an eradication plan to deal with the potential threat to public health. The plan has involved spraying baggage tunnels with insecticide and poisoning the breeding sites in the bollards with larvicide.
"Department of Agriculture and the state Health Department are liaising with the airport to ensure all identified breeding sites are effectively treated," a Department of Agriculture spokesman said.
"[The department] is currently undertaking enhanced surveillance at the airport, including daily monitoring of mosquito traps."
The aedes aegypti mosquito, which is a common "vector" for spreading diseases like dengue and yellow fever, are typically found in tropical and subtropical climates such as in Queensland, Africa and Asia.
The symptoms of dengue fever, also known as breakbone fever, include fever, headache, joint and muscle pain, vomiting and diarrhoea. Its advanced but rare forms – dengue haemorrhagic fever and dengue shock syndrome – can result in organ damage, coma and death.
Sources say an investigation is under way to discover how the mosquitoes slipped through Australia's stringent quarantine protocols.
The revelations come as the federal government is pushing to cut costs in the Department of Agriculture. About 230 jobs are tipped to go in the next financial year, including 34 in Victoria.
Community and Public Sector Union national secretary Nadine Flood said the union was "deeply concerned" about the impact of ongoing cuts on frontline bio-security and border protection services. "The risk here is that government saves a dollar now but faces massive costs down the track when dealing with disease."
The Victorian Department of Health reports 64 people had dengue fever in Victoria from January to early March, down from 79 people in the same period in 2013 and 105 in 2012. These cases typically involved infected travellers returning home.