Resources on Health and Disease in Africa (University of Pennsylvania) is an excellent single website that provides researchers, students, and the general public with resources that are integral to understanding health concerns in Africa including individual diseases.
ELDIS,the most important development website maintained by the Institute of Development Studies, Sussex aims “to share the best in development, policy, practice and research.” ELDIS provides links to full text documents related to development including health issues as well as individual country information on public health and disease.
Medical Ecology connects the impact of the environment on human health and disease. Contains sections on air/water/food as well as various infectious diseases.
TDR, the Special Programme for Research and Training in Tropical Diseases, is a global programme to combat a portfolio of major diseases of the poor and disadvantaged. TDR is based at and executed by the World Health Organization (WHO), and is sponsored by the United Nations Children's Fund (UNICEF), the United Nations Development Programme (UNDP), the World Bank and WHO.