particularly susceptible to  dengue are favelas and under-developed areas - in fact, unmonitored stagnant water in pools, water tanks, thrown away bottles, and similar areas are the perfect breeding area for infectious mosquitoes.

visitors planning on taking favela tours and / or finding accommodations in hostels in these areas should be extra aware of the precautions against  dengue fever, should use insect repellent in abundance, and stay in air-conditioned lodging recently treated for insects and mosquitoes.

previously known as dengue hemorrhagic fever, dengue risk areas are centered mostly in the northeastern brazil, in regions of recife, natal, and fortaleza - in rio de janeiro in particular, the predicted risk has been located at around a medium level, along with the cities of salvador and manaus.