Notifiable Diseases
Notifiable diseases are diseases "that, by law, must be reported to public health authorities upon diagnosis." The CDC maintains a revised list of nationally notifiable diseases but reporting by states is voluntary. Currently, reporting notifiable diseases is mandatory by most states.
Nationally Notifiable Infectious Diseases
A list from the CDC.
Summary of Notifiable Diseases
Annual publication from Morbidity and Mortality Weekly Report.
Diseases Worldwide
Disease Control Priorities Project
"The Disease Control Priorities Project (DCPP) is an ongoing effort to assess disease control priorities and produce evidence-based analysis and resource materials to inform health policymaking in developing countries."
Global Burden of Disease
The World Health Organization provides information and statistics.