tetano
Editor, Senior Moderator
Am J Infect Control
. 2022 May 20;S0196-6553(22)00433-3.
doi: 10.1016/j.ajic.2022.05.009. Online ahead of print.
Viral transmissibility of SARS-CoV-2 accelerates in the winter, similarly to influenza epidemics
Shinako Inaida[SUP] 1 [/SUP], Richard E Paul[SUP] 2 [/SUP], Shigeo Matsuno[SUP] 3 [/SUP]
Affiliations
Abstract
Background: The transmissibility of SARS-CoV-2 is anticipated to increase in the winter because of increased viral survival in cold damp air and thus would exacerbate viral spread in community. Analysis to capture the seasonal trend is needed for monitoring, prevention, and controls.
Methods: We compared regression models for the 5-week case prior to each epidemic peak week for both the Covid-19 and influenza epidemics in winter and summer. The weekly case increase ratio was compared, using non-paired t-tests between seasons. In order to test the robustness of seasonal transmission patterns, the normalized weekly case numbers of Covid-19 and influenza case rates of all seasons were assessed in a combined quadratic regression analysis.
Results: In winter, the weekly case increase ratio accelerated before epidemic peaks, similarly, for both Covid-19 and influenza. The quadratic regression models of weekly cases were observed to be convex curves in the winter and concave curves in the spring/summer for both Covid-19 and influenza. A significant increase of case increase ratio (2.58 [95%CI:0.01-6.37, p=0.049]) of the Covid-19 and influenza epidemics was observed in winter as compared to spring/summer before the epidemic peak.
Conclusions: The epidemic of Covid-19 was found to mirror that of influenza, suggesting a strong underlying seasonal transmissibility. Influenza epidemics can potentially be a useful reference for the Covid-19 epidemics.
Keywords: Covid-19; case increase ratio; influenza; transmissibility; winter.
. 2022 May 20;S0196-6553(22)00433-3.
doi: 10.1016/j.ajic.2022.05.009. Online ahead of print.
Viral transmissibility of SARS-CoV-2 accelerates in the winter, similarly to influenza epidemics
Shinako Inaida[SUP] 1 [/SUP], Richard E Paul[SUP] 2 [/SUP], Shigeo Matsuno[SUP] 3 [/SUP]
Affiliations
- PMID: 35605752
- DOI: 10.1016/j.ajic.2022.05.009
Abstract
Background: The transmissibility of SARS-CoV-2 is anticipated to increase in the winter because of increased viral survival in cold damp air and thus would exacerbate viral spread in community. Analysis to capture the seasonal trend is needed for monitoring, prevention, and controls.
Methods: We compared regression models for the 5-week case prior to each epidemic peak week for both the Covid-19 and influenza epidemics in winter and summer. The weekly case increase ratio was compared, using non-paired t-tests between seasons. In order to test the robustness of seasonal transmission patterns, the normalized weekly case numbers of Covid-19 and influenza case rates of all seasons were assessed in a combined quadratic regression analysis.
Results: In winter, the weekly case increase ratio accelerated before epidemic peaks, similarly, for both Covid-19 and influenza. The quadratic regression models of weekly cases were observed to be convex curves in the winter and concave curves in the spring/summer for both Covid-19 and influenza. A significant increase of case increase ratio (2.58 [95%CI:0.01-6.37, p=0.049]) of the Covid-19 and influenza epidemics was observed in winter as compared to spring/summer before the epidemic peak.
Conclusions: The epidemic of Covid-19 was found to mirror that of influenza, suggesting a strong underlying seasonal transmissibility. Influenza epidemics can potentially be a useful reference for the Covid-19 epidemics.
Keywords: Covid-19; case increase ratio; influenza; transmissibility; winter.