I’m not sure, but perhaps eradicating the Aedes aegypti is enough to prevent most of the dengue transmission.
And the Aedes albopictus (Tiger mosquito) is also a non native specie in Brazil, so it’s probably a good idea to eradicate it too, perhaps using the same method. http://en.wikipedia.org/wiki/Aedes_albopictus
"Then there’s the possibility that as Aedes aegypti mosquitos are killed off, other species will just take their place.
Phil Lounibous, an insect ecologist at the University of Florida, says getting rid of Aedes aegypti won’t necessarily solve the dengue problem.
'The so-called Asian Tiger mosquito is (also) very abundant all throughout Brazil,' Lounibous says, 'and it ... is also a vector of dengue.'"