Dengue fever could make its appearance in Brisbane, while infected mosquitoes will survive in winter in rainwater tanks

Damaged rainwater tanks that are a winter sanctuary for Aedes aegypti Mosquitoes increase the risk of dengue epidemic in Brisbane, warned scientists.

Aedes aegypti Mosquitoes infect millions of people in the tropics worldwide with disabling diseases such as dengue, zika and chikungunya.

Its range extends into the tropical north of Australia. The species is present on the east coast of the Torres Strait through Townsville, Mackay and Rockhampton until north of Brisbane where it does not usually survive in winter.

Aedes aegypti mosquitoes infect millions of people in the tropics around the world with disabling and debilitating diseases such as dengue, zika and chikungunya. Rainwater tanks help species move south to Brisbane because the large expanse of water isolates their larvae from the cold of winter

However, the species could be established in Brisbane, according to a new study by the CSIRO (Commonwealth Scientific and Industrial Research Organization), which says that rainwater tanks with holes, missing screens or water points not connected are a survival habitat for mosquitoes in winter.

If the species finds protection in Brisbane for a year, it could expose its 2.3 million residents to a risk of epidemic.

The main disease is dengue, which causes a serious illness resembling the flu with a high fever.

A small proportion of people develop severe dengue fever that causes bleeding and shock, which can be life-threatening.

Broken, rusty or missing sieves from rainwater tanks allow mosquitoes to enter and exit

In the past, severe dengue cases have resulted in deaths in Queensland.

CSIRO scientist Brendan Trewin told ABC that in controlled experiments simulating Brisbane winters, 70% of Aedes Aegypti larvae had reached adulthood in water tanks of rain, compared to only 50% in buckets of water.

"What we have seen in the rainwater tanks is the large volume of water buffers or, in a way, the minimization of temperature fluctuations. They are therefore an ideal container for the juvenile stages of the insect, "said Dr. Trewin.

People who own rainwater tanks have been asked to repair holes that allow mosquitoes to enter and lay their eggs.

Aedes aegypti mosquitoes are a tropical species found in Queensland, from the Torres Strait north of Brisbane. They can carry dengue, zika and chikungunya

Drilled holes in overflows or sieves to allow water to flow more quickly facilitate the entry and exit of mosquitoes.

Changing the tank leaving the sieve off provides open access to mosquitoes.

The CSIRO urged people to check their rainwater tanks to make sure that the sieves cover the entrance and overflow, that they are not rusted and that they are not rusty. they are not punctured.

Homeowners should also ensure that there is no void, looking for cracks in the tank and that the first flush devices are emptying properly.

CSIRO told ABC that in the early 1900s, nearly 90% of Brisbane residents were exposed to dengue fever, but that in the last few decades, it has not occurred. There had been no epidemic in the city.

Brisbane residents were asked to seal their water outlet connections

According to the annual report of the National Advisory Committee on Arbovirus and Malaria for 2014-2015, published in April, the vast majority of dengue cases were brought by travelers, the majority coming from Indonesia.

In 2014-2015, 74 dengue virus notifications were acquired in Australia, but 1,592 dengue virus notifications acquired abroad, imported into Australia by travelers.

Of these, 1046 cases, or two-thirds, came from Indonesia, a large proportion of which were related to trips to Bali.

In 2014-2015, 12,849 notifications of mosquito-borne diseases were reported in Australia, the vast majority (83%) of which were from the Barmah Forest Virus and Ross River Virus.