While residents of Southern states have been basting, expiring or find themselves left stranded as transport and energy grids lurch through the heatwave, folks in Far North Queensland have been contending with a dengue fever epidemic and pretty well ideal wet seasons for the breeding cycle of the carrier, the aedes aegypti mosquito.

At time of writing the number of cases in Cairns had reached 266 spread across nearly 20 suburbs. Half a dozen suburbs in Townsville accounted for another 47 cases. While the AAP described it as the worst dengue outbreak in 70 years, authorities reported that there had been 278 cases of type 2 dengue record in the Torres Strait in 2003/04.

After copping such a recent hammering, you wonder what poor old Australian Quarantine and Inspection Service could have done to stop this latest epidemic going through to the keeper. A lone Indonesian ‘Typhoid Mary’ traveller is thought to have introduced type 3 Dengue fever to Cairns before Christmas.

Queensland’s Acting Chief Health Officer Linda Selvey said that symptoms associated with this particular outbreak are severe and that the epidemic could take months to eliminate. The symptoms are unpleasant to put it mildly: intense headaches and muscle pain, extreme fatigue and possible bleeding from nose and gums. Infection by one strain does not provide immunity against the other three.

Queensland’s Tropical Population Health Service is so concerned about an outbreak on Thursday Island (there is a lot of travel between T.I. and the mainland at this time of the year) that it’s acting on the assumption that the disease has reached the community and is deploying its “vector control teams” to visit every dwelling on the island over the next fortnight.

Their job is to ensure that stagnant water in pot plant bases, old tyres, boats, playground equipment etc is cleared. The one note of positive news is that dengue is one disease that can be controlled by this simple measure.

Before Southerners relax, consider a grim prognosis in the form of an article in Functional Ecology, the journal of the British Ecological Society. Co-authors including Michael Kearney of the University of Melbourne concluded that all those rainwater tanks we’ve been encourage to install are likely to enable aedes aegypti to “dramatically re-expand the mosquito’s current range”.

Dr Linda Selvey of Queensland Health talks about another species of mosquito from PNG already in a holding pattern on the outer islands of the Torres Strait with the capability of carrying dengue south and surviving very comfortably in the more temperate climes of Sydney and Melbourne.
(TIP: replace the mesh over your tank inlet with one1mm brass).

Figures on the epidemic hot off the press from Queensland Health:

Cairns

  • Total number of cases: 277
  • Dengue type 3
  • Suburbs affected (local transmission): Aloomba, Bayview Heights, Bungalow, Cairns North, Clifton Beach, Earlville, Edge Hill, Kewarra Beach, Machans Beach, Parramatta Park, Smithfield, Westcourt, Whitfield, Yorkeys Knob.
  • Date outbreak declared: 1 December 2008

Townsville

  • Total number of cases: 47 (35 type 1, six type 3, and remainder are yet to be typed)
  • Dengue types 1 and 3
  • Suburbs affected (local transmission): Belgian Gardens, Kirwan, North Ward, Rowes Bay, South Townsville, Wulguru.
  • Date outbreak declared: 5 January 2009