Figure 1. Onset time of 44 confirmed cases of influenza A (H7N9) virus human infection — Zhejiang Province, China, 2013.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.