Questão 86

About half of the world’s population is at risk of contracting dengue, according to the World Health Organization. The mosquito is found $\in$ tropical and subtropical climates around the world; however, dengue does not naturally occur $\in$ these creatures: the mosquitoes get dengue from us.

    The mechanism of dengue infection is simple. Female mosquitoes bite humans because they need the protein found $\in$ our blood to produce eggs. (Male mosquitoes do not bite.) If the mosquito bites someone with dengue – and then, after the virus’s roughly eight- to 12-day replication period, bites someone else – it passes dengue into its next victim’s bloodstream.

    There is no vaccine against dengue, but infecting mosquitoes with a natural bacterium called Wolbachia blocks the insects’ ability to pass the disease to humans. The microbe spreads among both male and female mosquitoes: infected females lay eggs that harbor the bacterium, and when Wolbachia-free females mate with infected males, their eggs simply do not hatch. Researchers are now releasing Wolbachia-infected females into the wild $\in A$ustralia, Vietnam, Indonesia and Brazil.

Scientific American, June 2015. Adaptado.

De acordo com o texto, a infecção por dengue