a1 Tongling Centre for Disease Control and Prevention, Tongling, Anhui, China
a2 Jiangsu Provincial Centre for Disease Control and Prevention, Nanjing, China
a3 Tongren Centre for Disease Control and Prevention, Tongren, Guizhou, China
a4 Chinese Field Epidemiology Training Programme, Chinese Centre for Disease Control and Prevention, Beijing, China
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.
(Received July 08 2013)
(Revised December 09 2013)
(Accepted January 24 2014)
(Online publication February 24 2014)
c1 Author for correspondence: Dr Y. F. Zhu or Dr F. Y. Tang, Jiangsu Provincial Centre for Disease Control and Prevention, Nanjing, China. (Email: firstname.lastname@example.org) [Y. F. Zhu] (Email: email@example.com) [F. Y. Tang]
† These authors contributed equally to this work.