Analysis of influenza surveillance in Dehong Prefecture， Yunnan Province from 2016 to 2020 / 上海预防医学

ABSTRACT

ObjectiveTo perform the analysis of influenza surveillance in Dehong from 2016 to 2020 and determine the epidemic situation of influenza and prevalent virus strains， so as to provide evidence for local influenza prevention and control. MethodsThe influenza surveillance data in Dehong Prefecture was collected from January 2016 to December 2020. Statistical analysis was conducted by descriptive epidemiological methods. ResultsA total of 4 146 samples from influenza-like illness cases were examined. The 502 specimens tested positive for influenza virus， including 311 cases with influenza A virus and 136 cases with influenza B virus， resulting in a positive rate of 12.11%. The positive rate was the highest in 2017， followed by 2019， and the lowest in 2020 （P < 0.05）. It peaked in winter and fall. Furthermore， it was the lowest among children aged 0‒4 years and the highest among adults aged 25‒59 （P < 0.001）. In addition， positive rate did not differ significantly by gender（P>0.05） ConclusionThe positive rate of influenza has decreased in Dehong since January 2020. The influenza epidemic is seasonal， mainly in fall and winter， except 2020. Influenza A virus is predominant， compared to alternating influenza B virus.