World Health Organization. Offers extensive listing of health topics (such as influenza and cancer), and a large collection of health information, broken down by participating country. Health statistics and news are also contained in this site.
Pan American Health Organization (PAHO). International health organization focusing on the Americas. Offers regional news and scientific information.
United States - Federal
Centers for Disease Control (CDC). Extensive listing of health topics, including an alphabetical listing of information on diseases and conditions. Offers news, podcasts, and statistics.
United States - State Agencies
New York State Department of Health. Posts health news affecting New York state. Also lists a large number of "Current Issues", including topics such as Influenza and Medicaid.
State and Local Health Departments. The American Public Health Association has assembled a long list of state and local health department links.
State Health Departments (MMWR). This resource from MMWR offers a clickable map to locate state health department web pages.