The Department of Virology at the Teaching Hospital Na Bulovce, Prague, started routine diagnostic tests for DF in 1998. During 1998-2002, 328 patients were examined and serological evidence of acute DF (A90) was found in 15 patients. One case was diagnosed as “post-acute DHF” (A91). She was a 45-year-old woman who was admitted to the Department of Infectious Diseases, Prague. She had returned from Bangkok where she had been hospitalized for haemorrhagic fever, but free from shock manifestations, for three weeks (4-24 May 2002). In the Czech Republic, her diagnosis was confirmed at the Department of Virology at the Teaching Hospital Na Bulovce, Prague. The results of the serological examinations of anti-dengue antibodies carried out at this Department from 1998 to 2002 are presented in Table 2.