Isolation and identification of influenza viruses from clinical materials in 1977-1993 at Veterans General Hospital-Taipei.

From 1977 to 1993, 15,189 throat swab samples were received for isolation and identification of influenza virus in the Clinical Virology Laboratory, Veterans General Hospital-Taipei. Most of the samples came from the Pediatric Department. There were 634 identified strains of the influenza virus; the successful isolation rate was 4.17% in average/year. Among these isolates, 56.3% (357/634) were influenza B; 12.1% (77/634) were influenza A/H1N1 and 28.1% (178/634) were influenza A/H3N2. About 3.5% (22/634) were classified as flu-like agents because of no reaction with available monoclonal antibodies. In recent years, reverse transcriptase polymerase chain reaction (RT-PCR) was established here to re-evaluate these virus stocks. This method can provide rapid diagnosis method to identify influenza A/H1N1, A/H3N2 and B. Further, the RT-PCR method and sequencing of amplified DNA could be used to see the variation of virus isolates which were recirculated or which reappeared in the Taipei area.