title: Age-specific differences in influenza A epidemic curves: do children drive the spread of influenza epidemics?
abstract: There is accumulating evidence suggesting that children may drive the spread of influenza epidemics. The objective of this study was to quantify the lead time by age using laboratory-confirmed cases of influenza A for the 1995/1996-2005/2006 seasons from Canadian communities and laboratory-confirmed hospital admissions for the H1N1/2009 pandemic strain. With alignment of the epidemic curves locally before aggregation of cases, slight age-specific differences in the timing of infection became apparent. For seasonal influenza, both the 10-19- and 20-29-year age groups peaked 1 week earlier than other age groups, while during the fall wave of the 2009 pandemic, infections peaked earlier among only the 10-19-year age group. In the H3N2 seasons, infections occurred an average of 3.9 (95% confidence interval: 1.7, 6.1) days earlier in the 20-29-year age group than for youth aged 10-19 years, while during the fall pandemic wave, the 10-19-year age group had a statistically significant lead of 3 days compared with both younger children aged 4-9 years and adults aged 20-29 years (P < 0.0001). This analysis casts doubt on the hypothesis that younger school-age children actually lead influenza epidemic waves.
authors: Modeling and Projection Section, Infectious Disease Prevention and Control Branch, Public Health Agency of Canada, 100 Eglantine Driveway, Tunney’s Pasture, Ottawa, Ontario K1A 0K9, Canada. dena.schanzer@phac-aspc.gc.ca
authors: Dena
authors: D
authors: Schanzer
authors: Julie
authors: J
authors: Vachon
authors: Louise
authors: L
authors: Pelletier
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