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.
Distribution of the study sites. The map shows location of the study sites and distribution of confirmed cases in the five towns of Feixian county in southern Shandong province, China. The numbers in parentheses denote the total number of cases in each town during the 12-year study period.
