Influenza virus infections in Taiwan from 1979 to 1995.

In order to understand the epidemic trends of influenza virus infection in Taiwan, 5,882 throat-swab specimens were collected from June 1979 to June 1995. Influenza virus was detected in 313 specimens including samples collected at Taichung and Tainan from 1981 to 1982. Among them, 214 isolates (68.4%) were identified as influenza virus type A, and 99 (31.6%) as type B. In the course of the surveillance, the influenza virus strain A/Taiwan 1/86 (H1N1), known as a world-wide reference strain, was isolated in April 1986. Influenza virus infection was identified throughout the year in Taiwan based on the frequency of detection of the virus. Some strains were referred to as intermediate strains in comparison with the reference strains on the basis of antigenic heterogeneity. About 80% of the isolates identified in this laboratory were from children under 12 years old. The rate of isolation of virus was about 46% during the epidemic season.