United Nations -- Data on the health indicators related to the Millennium Development Goals is available at http://unstats.un.org/unsd/mi/mi_goals.asp .
World Bank -- The World Bank provides time series data for Health in its database, the World Development Indicators (WDI) and a separate health, nutrition and population data base at the same site.
World Health Organization-- WHO provides access to searchable data bases and other data sources on disease at http://www.who.int/research/en/ .
The World Resources Institute -- The WRI providesfree online data in EarthTrends. WRI provides a searchable time-series database with a range of indicators for more than 140 countries. Topics include Population, Health and Human Well-being. The searchable database permits searching for a single indicator but over a full range of countries and years. The result can be downloaded into csv format. The system also provides data tables and country profiles in pdf format, maps and feature stories. The database is available at http://earthtrends.wri.org/ . It is necessary to register to get access to some of the data, but registration is free.
Gapminder -- Gapminder is an innovative data presentation web site which provides dynamic views of data changes over time using bubble graphs. Graphs are available for economic, population, health (including HIV/AIDS), environmental, agricultural and information technology data. Raw data can be downloaded from the site and a desktop version of the software is available free. Users can customize graphs using existing data, but cannot add new data. Much of the data used is from the World Bank and UN organizations. Gapminder is at http://www.gapminder.org .
US Census Bureau -- The US Census Bureau has for many years been collecting data on HIV/AIDS surveys in developing countries. The Bureau provides free access to this data base, The HIV/AIDS Surveillance Data Base at http://www.census.gov/population/international/data/hiv/. . Data can be downloaded in either ASCII or Lotus format.
UNAIDS-- UNAIDS most recent publication of time series data as an .xlsx spreadsheet is the "HIV estimates with uncertainty bounds 1990 to 2011" available at http://www.unaids.org/en/resources/campaigns/20121120_globalreport2012/globalreport/. The data in this report is more accessible than the data published in the earlier reports in this series, however, the spreadsheet still contains mixed text and numeric data in many of the cells and the text caracters must be cleaned out and the cells formatted as numeric before the data can be used for calculations. The full report can also be downloaded as a .pdf file from this page. Users looking for specific data by country can use the AIDSinfo Online Database http://www.aidsinfoonline.org/devinfo/libraries/aspx/Home.aspx. For database users,a download of all of the data in the AIDSinfo Online Database is available at the "Download data in CSV format" label on the same page. The full download contains more than 200,000 individual records.