Fig. 1.
Global trends in cases of wild poliovirus infection, 2001–2009a
WPV, wild poliovirus; WPV1, wild poliovirus type 1; WPV3, wild poliovirus type 3.
a Cases for 2009 reported until 8 December.
Based on data from the World Health Organization.
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.