[3 dengue fever cases, infected during a group tour to the Philippines].

: We report three dengue fever cases, infected during a group tour to the Philippines. A 58-year old male experienced sudden onset of high fever 5 days after returning to Japan, followed by rash and thrombocytopenia. The other 2 cases experienced similar symptoms. Clinically suspected from the travel history, incubation time and the state of dengue fever epidemic in the Philippines, dengue virus infection was confirmed by the laboratory tests. The incidence and geographical distribution of dengue virus infection have greatly increased in recent years. There have been reports of Japanese travelers who visited dengue endemic countries, infected and developed symptoms after returning home. Dengue virus infection should be included in the differential diagnosis of the patients who develop high fever and rash after returning from tropical areas.