WorldCat provides access to library catalogs from around the world. The database contains millions of bibliographic records describing books, journals, maps, musical scores, recordings, videos, manuscripts, etc.
Although this is mainly a site with U.S. information, the CDC contains general information on diseases and conditions and includes a Global Health section (see upper right, "More CDC Topics".)
Part of NIH, the FIC "is dedicated to advancing the mission of the National Institutes of Health (NIH) by supporting and facilitating global health research conducted by U.S. and international investigators, building partnerships between health research institutions in the U.S. and abroad, and training the next generation of scientists to address global health needs."
130,000 development documents produced for or by the US Agency for International Development. 25,000 are available full-text; check with Document Center about access to others
The online library of the Organisation for Economic Cooperation and Development (OECD) featuring its books, papers and statistics. Search for health-related publications or statistics here.