The Brazilian Ministry of Health has warned that as of June 2018, outbreaks of dengue fever, Zika virus, and chikungunya may be ongoing in more than 1150 municipalities across the country. More than 5000 are at risk due to conditions conducive to the presence of the Aedes aegypti mosquito, potential carriers of all three diseases, as well as yellow fever.
The state capitals at the highest risk are Cuiabá and Rio Branco. The following capitals are on alert: Rio de Janeiro, Fortaleza, Porto Velho, Palmas, Maceió, Salvador, Teresina, Recife, Brasília, Vitória, São Luis, Belém, Macapá, Manaus, and Goiânia. A full list of concerned municipalities is available here.
According to the most recent statistics released by the ministry, in the first four months of 2018 a total of 110,291 cases of dengue fever were reported nationwide; the worst hit region was the Center-West (40,806 cases), following by the Southeast (36,801), the Northeast (21,267), the North (8915), and the South (2502). During the same period, 32,200 cases of chikungunya were reported; the worst hit region was the Southeast (13,067 cases), following by the Center-West (11,466), the Northeast (4754), the North (2692), and the South (221). Finally, a total of 3266 cases of the Zika virus were reported.
Symptoms of dengue fever include fever, headache, muscle and joint pain, fatigue, nausea, and rashes. Dengue Hemorrhagic Fever (DHF) is a potentially deadly complication that is characterized by high fever, the enlargement of the liver, and hemorrhaging.
Symptoms of chikungunya are similar; the virus is infrequently fatal but potentially debilitating joint pain can last for weeks, even months, after the initial recovery.
Symptoms of Zika - fever, headache (behind the eyes), conjunctivitis, rash, vomiting, and muscle and joint pain - can appear two to seven days following contraction of the disease, although the virus is asymptomatic in approximately 80 percent of cases. Transmission of the virus is also possible via sexual intercourse. Although the Zika virus is usually relatively benign, links between it and severe birth defects as well as the potentially fatal neurological disorder Guillain-Barre syndrome (GBS) have been established.
Individuals present in Brazil - in particular pregnant women and their partners - are advised to take measures to protect themselves from mosquito bites (e.g. by wearing covering clothing, using insect repellent, and sleeping in screened-in or air conditioned rooms) and to eliminate possible mosquito breeding grounds (small pockets of fresh water, such as rain water that has collected in cans, bottles, tires, flower pots, clogged gutters, etc.).