According to figures released by the Costa Rican government on April 24, transmission rates of mosquito-borne diseases continue to remain at relatively low levels. There were 136 cases of the Zika virus registered in the first 14 weeks of the year (period ending April 8), compared to 745 reported in the same period of 2017. During the same 14-week period, 474 cases of dengue fever and 23 cases of chikungunya were also reported, compared to 5437 and 141 in 2017 respectively. A nationwide campaign to reduce populations of all of the Aedes aegypti mosquito - a carrier of all diseases - continues.
No locally acquired cases of malaria, transmitted by a different type of mosquito, have been reported since the beginning of the year.
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 Costa Rica - 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.).