The skewing may reflect a bias towards the males simply because they could be more involved in activities that increase their risk of exposure to the influenza A(H7N9) virus host or its environmental source.
Returning to the issue of H7N9 and its skewed presentations in the sexes.
I wrote about this on the 22.04.13 but forgot to mention that there are no accompanying descriptions of the societal roles of males and females in these areas, or in general.