Abstract
Human infection with the emerging avian influenza A(H7N9) virus in China in 2013 has raised global concerns. We conducted a retrospective descriptive study of 27 confirmed human influenza A(H7N9) cases in Jiangsu Province, to elaborate poultry-related exposures and to provide a more precise estimate of the incubation periods of the illness. The median incubation period was 6 days (range 2-10 days) in cases with single known exposure and was 7·5 days (range 6·5-12·5 days) in cases with exposures on multiple days, difference between the two groups was not significant (Z = -1·895, P = 0·058). The overall median incubation period for all patients was estimated to be 7·5 days (range 2-12·5 days). Our findings further highlight the necessity for public health authorities to extend the period of medical surveillance from 7 days to 10 days.