A Serological Study of Dengue Virus Infection among Japanese Residents in Manila.

A total of 84 serum specimens were collected from 67 Japanese residents in Manila, the Philippines, at a clinic during the periods from September 1992 through February 1993 and November 1993 through March 1994, during which time dengue viruses were actively circulating, and tested for antibodies to dengue (DEN) viruses. Fifteen (22.4%) individuals were confirmed as recent DEN infection by either the detection of anti-DEN IgM or a four-fold or more rise in neutralizing antibody titer in acute-convalescent paired sera. Major serotypes of current DEN epidemic appeared to be DEN type 1 and type 2 viruses. There was a case in which all three members of a family had been infected with DEN simultaneously, and their symptoms varied from DEN fever to DEN hemorrhagic fever.