Epidemiological investigation and analysis on the outbreaks of the diseases induced by influenza B virus

Objective The present study was conducted to find out the occurrence, progress, and damage of the outbreaks of the diseases induced by influenza B virus in order to establish scientific measures to prevent and control the outbreaks. Methods The epidemic situation was studied by describing the distributions of time, spot and population, clinical signs, nucleotide testing, virus isolation, and analysis on gene mutation. Results Epidemic outbreaks caused by Victoria lineage influenza B spread rapidly and widely. The attack rates and positive rates of virus nucleotide testing were both high. As time went on, the two above rates decreased. The clinical symptoms were relative light and the prognosis was good. Conclusion It is necessary to pay more attention to Victoria lineage influenza B, and take scientific and strong measures as early as possible.