[Dengue fever].

Dengue virus infections have increased globally. This results in an increased incidence of patients with dengue fever in Denmark. In order to draw attention to this diagnosis among febrile persons returning from a stay in tropical and subtropical areas, we present two cases of dengue virus infection and describe the symptoms and diagnostic possibilities. Dengue Haemorrhagic Fever (DHF) is supposed to occur only in persons who have previously had dengue virus infection and who acquire a second infection with dengue virus.