Just a few days before Carnival in Rio de Janeiro, the city administration declares a health emergency due to the rapidly spreading dengue fever. The disease is transmitted by mosquitoes. What constitutes the disease – an overview.

The virus is typically recognized by three symptoms that occur at the same time: fever, rash and headache, limb or joint pain. In rare cases, internal bleeding and shock also occur.

With today’s healthcare system, most cases are easily treatable. This means that long-term consequences rarely occur. In 1.5 percent of infections, the disease becomes severe and can lead to death. However, with early detection, the death rate falls below one percent.

The safest protection against infection is reliable mosquito repellent. The virus is transmitted by yellow fever mosquitoes. Occasionally also by tiger mosquitoes. So if you prevent a mosquito bite by using mosquito repellent, you are also protecting yourself from dengue fever. You can also avoid still waters and wear a mosquito net.

A vaccination against dengue fever is recommended if you often travel to tropical areas, because the mosquitoes that transmit it are particularly active there. There are currently two approved vaccines against the virus in Europe, which since February 2023 you can have injected by your family doctor or a tropical medicine doctor, even while on vacation.

In Germany there have not yet been any registered cases that were proven to have been transmitted by a mosquito. According to the Robert Koch Institute, around 600 cases in 2018 and over 1,000 cases in 2019 were imported infections, mostly from Southeast Asia.

The Federal Foreign Office informs that travelers in Brazil should pay particular attention to good mosquito protection during the day and in the evening. “Mosquito repellents are available in the country, but not all of them in the necessary concentration. You should therefore bring them from Germany, at least to start with,” it says. For a vaccination, the Federal Foreign Office recommends individual medical advice before the trip, especially for longer stays. “The vaccination is available in Brazil in private vaccination centers, so that even if the preparation time is short, vaccination can be started before leaving the country. Protection can only be expected two weeks after the first vaccination at the earliest.”

Sources:  Tropical Institute, Federal Ministry of Social Affairs and Health, Federal Foreign Office, RKI