The number of probable cases of dengue fever has almost doubled in just one week in Brazil. According to the Ministry of Health, almost 120,000 cases were registered in the first three weeks of the year. At the end of January there were almost 220,000, an increase of 80 percent in one week and three times the same period last year. 15 deaths were attributed to the viral disease in January, while 149 additional cases were still under investigation. Chikungunya virus infections have also risen sharply year-on-year.
Experts point to the hot and rainy weather in the summer months as the reason for the rapid spread of the dengue and chikungunya viruses in Brazil and other South American countries, such as Paraguay and Argentina. This promotes the reproduction of the Egyptian tiger mosquito or yellow fever mosquito (Aedes aegypti), which also transmit dengue, among other things. The mosquitoes lay their larvae in stagnant water, where they hatch within a few days in warm conditions. Even the smallest water deposits accumulated in plastic waste lying around serve as breeding grounds for the larvae. This makes their spread difficult to control.
In addition to the annual information campaigns and the fight by spraying pesticides in particularly affected areas, Brazil has had a new weapon against dengue for a few weeks now. In view of the sharp increase in the number of cases, a vaccination campaign has started. This is made possible by a new vaccine called Qdenga from the Japanese manufacturer Takeda, which was approved by the authorities in December. Brazil has already received several hundred thousand doses. There should be 6.5 million by the end of the year. The vaccination campaign is aimed at children aged six and over. Qdenga is also already approved in the European Union, Indonesia and Thailand.
Petra Ahne Published/Updated: , Recommendations: 20 Published/Updated: Recommendations: 9 Published/Updated: Recommendations: 7
In most cases, dengue fever has no symptoms. In around 20 percent of all cases, an infection is accompanied by fever, chills and severe headaches and body aches. Severe cases usually occur, especially after a second infection. The mortality rate for severe cases is between one and five percent.