tetano
Editor, Senior Moderator
Int J Infect Dis
. 2022 Jun 16;S1201-9712(22)00354-X.
doi: 10.1016/j.ijid.2022.06.022. Online ahead of print.
Global variation in early epidemic growth rates and reproduction number of seasonal influenza
R Thompson[SUP] 1 [/SUP], J G Wood[SUP] 1 [/SUP], S Tempia[SUP] 2 [/SUP], D J Muscatello[SUP] 3 [/SUP]
Affiliations
Abstract
Introduction: Little is known about global variation in early epidemic growth rates and effective reproduction numbers (R[SUB]e[/SUB]) of seasonal influenza. We aimed to estimate global variation in R[SUB]e[/SUB] of influenza type A and B during a single period.
Methods: Country influenza detection time series from September 2017 through January 2019 were obtained from an international database. Type A and B epidemics by country were selected based on R[SUB]e[/SUB] estimates for a five-week moving window advanced by week. Associations of R[SUB]e[/SUB] with absolute latitude, Human Development Index, percent of the population aged <15 years and percent living rurally in each country were assessed.
Results: Time series were included for 119 of 169 available countries. There were 100 countries with influenza A and 79 with B epidemics. Median R[SUB]e[/SUB] for both influenza A and B epidemics was 1.23 (ranges: A 1.10, 1.60; B 1.06, 1.58). R[SUB]e[/SUB] of influenza B, but not A, was independently associated with absolute latitude, increasing by 0.022 (95% CI 0.002, 0.043) per 10 degrees.
Conclusions: R[SUB]e[/SUB] of influenza A and B were similar. Only R[SUB]e[/SUB] of influenza B was associated with country characteristics; increasing with distance from the equator. The approach may be suitable for continuous R[SUB]e[/SUB] surveillance.
Keywords: Effective reproduction number; Epidemic dynamics; Geographic variation; Influenza type; Seasonal influenza.
. 2022 Jun 16;S1201-9712(22)00354-X.
doi: 10.1016/j.ijid.2022.06.022. Online ahead of print.
Global variation in early epidemic growth rates and reproduction number of seasonal influenza
R Thompson[SUP] 1 [/SUP], J G Wood[SUP] 1 [/SUP], S Tempia[SUP] 2 [/SUP], D J Muscatello[SUP] 3 [/SUP]
Affiliations
- PMID: 35718299
- DOI: 10.1016/j.ijid.2022.06.022
Abstract
Introduction: Little is known about global variation in early epidemic growth rates and effective reproduction numbers (R[SUB]e[/SUB]) of seasonal influenza. We aimed to estimate global variation in R[SUB]e[/SUB] of influenza type A and B during a single period.
Methods: Country influenza detection time series from September 2017 through January 2019 were obtained from an international database. Type A and B epidemics by country were selected based on R[SUB]e[/SUB] estimates for a five-week moving window advanced by week. Associations of R[SUB]e[/SUB] with absolute latitude, Human Development Index, percent of the population aged <15 years and percent living rurally in each country were assessed.
Results: Time series were included for 119 of 169 available countries. There were 100 countries with influenza A and 79 with B epidemics. Median R[SUB]e[/SUB] for both influenza A and B epidemics was 1.23 (ranges: A 1.10, 1.60; B 1.06, 1.58). R[SUB]e[/SUB] of influenza B, but not A, was independently associated with absolute latitude, increasing by 0.022 (95% CI 0.002, 0.043) per 10 degrees.
Conclusions: R[SUB]e[/SUB] of influenza A and B were similar. Only R[SUB]e[/SUB] of influenza B was associated with country characteristics; increasing with distance from the equator. The approach may be suitable for continuous R[SUB]e[/SUB] surveillance.
Keywords: Effective reproduction number; Epidemic dynamics; Geographic variation; Influenza type; Seasonal influenza.