Accessing libraries in plugins

I am developing an access plugin to run on 64-bit CentOS.  I am using the curl library to make a call to another server to do basic authentication.  I've installed the curl libraries via yum, and the code works using a test application.  I have the curl headers included like so:

#include <curl/curl.h>

When I start AMS, I see the following in the Edge log:

Info from AccessAdaptor: Can't load access adaptor /opt/adobe/ams/modules/access/libconnect.so Error=/opt/adobe/ams/modules/access/libconnect.so: undefined symbol: curl_easy_setopt.

Why can't the plugin access the curl library?