50,000 Dengue breeding sites found

Yesterday's April Fool's prank by Fiona and the team at ABC Far North about erecting a giant mosquito at the entrance to Cairns as an icon for our town, was clever and caught many a listener out on her talkback. Yet could not have been more appropriate.

Since the Dengue mosquito virus was unleashed on Cairns at the beginning of December, 50,000 potential mosquito breeding sites have been revealed.

Queensland Health now refers to this outbreak as an "epidemic".

With 824 confirmed Dengue infections of the violent fever, in just four months, 14,000 properties in the region have been inspected.

Whitfield, Cairns North, Edge Hill and Manoora have been the most active suburbs, which is now recorded as Cairns' largest dengue outbreak on record.

Inspections have found the type of water-holding items:

• rimless tyres (32 % of rimless tyres found were breeding mosquitoes)
  • buckets (29 %)
  • tarps/plastic (13 %)
  • bird baths (11%)
  • pot plant bases (11%)
  • boats (7%)
  • bromeliads (3%)
  • palm fronds (3%).

Most prolific breeding sites in terms of number of larvae found have been tarps/plastic, buckets, bird baths, tyres and pot plant bases.

This is a shocking line up as I revealed that in early March that the destroyed Cairns Yacht Club remains at James Cook University, has had a series of tarps haphazardly draped over it since November. Pooling water has been gathered all over the vast building ruins, with no attention to the mosquitoes breeding on it. With thousands of students living and working alongside, it's a preposterous situation of neglect.

“The message is clear, you can significantly reduce the number of dengue mosquitoes in your house by keeping your yard clear of any containers capable of holding water,” said Queensland Health Senior Medical Entomologist Brian Montgomery.

“This risk can be further reduced by filling your pot plant bases with sand, and changing the water in your bird bath once a week."

Montgomery says that bromeliads and fallen palm fronds can breed dengue mosquitoes, but they are not as significant as the artificial containers in yards.

Holloways Beach and Trinity Beach have been taken off the ‘dengue hotspot’ list for the current epidemic. They no longer have recorded recent dengue transmission. However, there are 15 Cairns' suburbs still active.

“There is a definite slowdown in the rate of confirmed dengue cases, but now is not the time for Cairns residents to be complacent,” Montgomery says. “Local residents need to continue working with us to clear potential dengue mosquito breeding sites, and go to their doctor if they are sick with symptoms of dengue, while doctors need to continue to notify us of suspected cases.
The recent drier weather has helped reduce adult dengue mosquito populations, but dengue mosquito eggs can survive in a container for six months after the water has dried out. Eggs are cemented along the water-line within a container and only hatch when re-flooded.

"With some rainfall, there is a risk that the number of dengue cases will increase again if residents leave these containers in their yards, thinking the dengue epidemic is slowing,” Brian Montgomery of Queensland Health says.

The Cairns epidemic has been particularly fast. In 2003-04, it took 69 weeks to reach 536 cases, while it took just 14 weeks to get to the same figure this year.