In the glow of daybreak in Joinville, a city in southern Brazil, a white minivan navigates the quiet residential streets. It is a scene that, at first glance, resembles a standard municipal pest control operation. But the team inside is not there to fumigate. They are not wearing masks to protect themselves from insecticides, and the tubes they are carrying do not contain chemicals.
Instead, they are holding mosquitoes — 72,000 of them.
Guided by a navigation app to reach a designated coordinate, a health professional leans out of the window, uncaps a tube, and shakes it. A small cloud of Aedes aegypti — the same species responsible for transmitting diseases such as dengue, Zika, and chikungunya — drifts into the air.
For decades, public health messaging in Brazil has been singular and martial: Eradicate the mosquito. Eliminate standing water. Fumigate the streets. Yet here, in the aftermath of the worst dengue crisis in the country’s history, the strategy has been inverted.