A recent study provides preliminary evidence of the long-term relationship between prevention and control measures and influenza transmission in China during the COVID-19 pandemic, explaining the impact under various levels of prevention and control. This study, the first of its kind, was published in Health Data Science, a Science Partner Journal.
Since December 2019, various non-pharmacological interventions (NPIs) and vaccination against COVID-19 have been used to prevent and control community transmission of COVID-19. However, the relationship between the changing influenza epidemic and the prevention and control of COVID-19 was unclear.”
Miss Zirui Guo, Department of Epidemiology and Biostatistics, School of Public Health, Peking University
Caused by the influenza virus, influenza is an acute respiratory infectious disease that can impose a high burden and lead to severe seasonal epidemics or even pandemics. However, early 2020 saw a marked decline in influenza activity in Japan and the United States, among other regions of the Northern Hemisphere. Additionally, Australia, Chile and other areas of the southern hemisphere shared this observation during their flu season. in 2020.
“The outbreak of COVID-19 changed the epidemic trend and characteristics of influenza, according to our analysis.” shares Professor Min Liu, author of the paper and scientist at the aforementioned organization.
A significant decrease in influenza activity was observed in China during the 2020-2022 COVID-19 pandemic, especially in winter and spring. In addition, seasonality of influenza was evident between 2010 and 2019, but was absent during the 2020/2021 season throughout China, both in northern and southern China.
The reduction in influenza viral infection could be related to everyday public health interventions for COVID-19 in China, the authors concluded after analyzing the epidemiology and seasonal patterns of influenza based on chronology of the current COVID-19 NPIs in China.
Respiratory illnesses tend to appear in the winter and spring, when COVID-19 and influenza tend to circulate easily. Meanwhile, the resurgence of other respiratory viruses once suppressed under the NPIs of COVID-19 in 2020-2021 was recognized worldwide. Thus, the entire population has lost the opportunity to improve immunity against influenza after an extended low flu season in 2020-2022. As a result, high-risk populations, such as young children and the elderly, are more vulnerable to severe and widespread illness from influenza as time goes on.
To protect these vulnerable populations, in addition to increasing influenza vaccine coverage, efforts should be made to strengthen influenza surveillance and establish a comprehensive surveillance system for influenza virus and SARS- CoV-2.
“Given the limitations of our analysis, additional studies should be conducted to confirm our results,” comments Professor Liu. “More indicators, such as the positive rate of influenza and the number of cases of influenza reports, could complement and verify our study. We will also consider the use of different prediction methods to validate our conclusions and make appropriate supplements in the future”.
Source:
Journal reference:
Guo, Z., et al. (2022) Impact of COVID-19 prevention and control on the influenza epidemic in China: a time series study. Health data science. doi.org/10.34133/2022/9830159.