A seven-foot-tall basketball player may be in excellent physical condition (although outside the range of normality for height) but may or may not be in good health depending, for example, on whether or not he has fallen victim to an attack of influenza.
In 1833, Wilberforce's health declined further and he suffered a severe attack of influenza from which he never fully recovered.
In 1898 he had an attack of influenza, and had apparently recovered, when he was again taken suddenly ill, and died on 17 June 1898.
273/284 islanders experienced a first attack of influenza, and 92/284 experienced a second attack.
While data were also reported on mortality from respiratory diseases, we chose to use the "fevers" data because pneumonia and bronchopneumonia were often complications that followed an attack of influenza rather than occurring, like fevers, when the disease itself peaked.
Until recent work [ 3, 32], based on data from 1918-19, there was even uncertainty about whether an attack of influenza in an early wave of the pandemic protected an individual in a later wave, as would be expected if the viruses in each wave were similar.
In this study, we were able to determine important covariates for natural attack rate of influenza and calculate age-specific and strain-specific attack rates that would serve as essential input parameters to an infectious disease model for influenza.
Attack rate of influenza B was lower than that of influenza A, with adults exhibiting an attack rate of 1.4% and children having an attack rate that is 5.6% higher than that of adults.
Across replicate simulations, we observe average yearly attack rates of 6.8% in temperate regions and rates of 7.1% in the tropics, comparable with estimated attack rates of influenza A (H3N2) of 3%to8%8% per year [ 10, 11].
However such a longitudinal study would require greater resources by several orders of magnitude than the one proposed here, due to the low attack rate of influenza.
