Rates of influenza A(H1N1)pdm09-associated influenza-like illness case-patients at three sentinel cities in Argentina, according to age group April–December, 2009.

aEstimated by multiplying the week-specific number of ILI cases identified (row 1) by the proportion testing positive for 2009 H1N1 (row 3) and its 95% confidence interval by the proportion of ILI cases among ILI physician visits (row 4) while adjusting for the proportion of cases-patients missing data on their epidemiologic week of illness.
bCorrected for the proportion of case-patients missing date of illness onset (epidemiologic week) information (i.e. 95 of 2,365 among children aged <5 years, 688 of 16,204 among persons aged 5–44, 101 of 2725 among persons aged 45–64 years, and 63 of 1180 among persons aged ≥65 years).