Travel and age of influenza A (H1N1) 2009 virus infection.
Age distribution of 4,986 cases of influenza A (H1N1) 2009 in Japan was analyzed. Cases with a travel history within 10 days preceding the illness onset were significantly older than indigenous cases (p < 0.01) reflecting age-specific travel patterns. Border controls should account for the high frequency of infection among adults.
Nishiura
Hiroshi
H
PRESTO, Japan Science and Technology Agency, Saitama, Japan. h.nishiura@uu.nl
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis* / Q000453:epidemiology*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D018570:Risk Assessment / Q000706:statistics & numerical data; D012307:Risk Factors; D014195:Travel / Q000706:statistics & numerical data*; D055815:Young Adult