Two cases of the fever were recorded in the Brumath commune, the report said. Those infected had recently arrived from Guadeloupe, where dengue fever is considered to be one of the most widespread tropical diseases. Another case was reported in Strasbourg.
Authorities in both regions have taken measures against the tiger mosquito, which is the main carrier of the infection, the broadcaster said.
In Guadeloupe, one of France's overseas departments in the Caribbean, more than 425 cases of dengue have been reported since the beginning of the year.
Dengue fever is a tropical disease caused by the dengue virus and transmitted to humans through the bite of an infected mosquito. The main vector of the disease is the Aedes aegypti mosquito. In the absence of a vector, infected humans do not pose an epidemiological threat.
According to the World Health Organization (WHO), most people can carry the disease without showing symptoms. Those who do have symptoms often experience high fever, headache, body aches, nausea and rash. The majority of patients recover in one to two weeks, but some people develop severe dengue, which includes shock or respiratory distress due to plasma leakage, severe bleeding or organ damage, which can lead to death.
Data from the WHO show that the mortality rate for severe cases of the disease is 2.5%, rising to 20% if adequate treatment is not provided. There is no cure for dengue fever, while the only prophylactic measure is to avoid being bitten by the tiger mosquito.