Brazil: Widespread risk of mosquito-borne diseases /update 9

Event

There is a widespread risk of contracting various mosquito-borne diseases in Brazil, including dengue fever, Zika virus disease, and chikungunya. According to the most recent statistics released by the Brazilian Ministry of Health, in the first 45 weeks of 2018 (period ending November 11), a total of 228,042 confirmed or likely cases of dengue fever were reported nationwide, including 136 fatalities. The highest case numbers have been reported in the Center-West (36.7 percent of cases), Northwest (28.1 percent), and Southeast (28.0 percent) regions.

During the same period, 82,382 confirmed or suspected cases of chikungunya were reported, including 35-83 deaths. The Southeast has been the worst hit (e.g. states of Rio de Janeiro, Pará, and Mato Grosso), with 59.7 percent of the cases.

Finally, a total of 7544 cases of Zika virus disease were also reported, with the highest case numbers reported in the Southeast (36.8 percent), Northeast (29 percent), and Center-West (21.2 percent) regions.

Context

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 virus disease - fever, headache (behind the eyes), conjunctivitis, rash, vomiting, and muscle and joint pain - can appear two to seven days following contraction of the infection, although the disease is asymptomatic in approximately 80 percent of cases. Transmission of the virus is also possible via sexual intercourse. Although Zika virus disease is usually relatively benign, links between it and severe birth defects as well as the potentially fatal neurological disorder Guillain-Barré syndrome (GBS) have been established.

Advice

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 (e.g. small pockets of fresh water, such as rainwater that has collected in cans, bottles, tires, flower pots, clogged gutters, etc.).