The HIV/AIDS pandemic presents political, economic, public health, social and scientific challenges to nations worldwide.  HIV/AIDS cases have been reported in all regions of the world, but most people living with the disease reside in low- and middle-income countries.  The past few years have brought greater international attention to HIV/AIDS and funding for the disease, but the need is much greater.  If more is not done to fight the HIV/AIDS pandemic, it is on course to be one of the worst in history, with millions more people estimated to become infected by the end of this decade.

State of the Pandemic
As of the end of 2007, 33 million people were estimated to be living with HIV/AIDS worldwide, according to the latest data from the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO).* The estimates indicate that the global HIV/AIDS prevalence rate (the percent of people living with the disease) has leveled off, although the number of people living with the disease continues to increase. An estimated 2.7 million people became newly infected with HIV in 2007, and 2.0 million people died of AIDS-related causes in 2007. Women comprise half (50%) of adults estimated to be living with HIV/AIDS worldwide. Young people under the age of 25 are estimated to account for more than half of all new HIV infections worldwide.

There is no single AIDS epidemic worldwide. Instead, many regions and countries are experiencing diverse epidemics, some of which remain in their early stages. Sub-Saharan Africa is the most-affected region in the world as measured by HIV/AIDS prevalence rates, followed by the Caribbean. There also is concern about the epidemic in parts of Eastern Europe and Asia.

Access to needed services remains low overall and uneven around the world. Although access to antiretroviral (ARV) treatment has increased dramatically since December 2003 in low- and middle-income countries, only 31% of people living with HIV/AIDS in need of ARVs were estimated to be receiving treatment as of December 2007 and most of these countries are far from reaching universal access goals. In addition, while some countries have implemented successful HIV prevention interventions among high risk populations and scaled up services for the prevention of mother-to-child transmission of HIV, others face severe shortfalls in the provision of these services.

Worldwide, financial resources for addressing HIV/AIDS in low- and middle-income countries have increased notably over time, but a significant resource gap remains. UNAIDS estimated that spending on HIV/AIDS rose from US$300 million in 1996 to US$10 billion in 2007. However, current spending falls far short of what is needed to respond to the epidemic. Sustaining and increasing current efforts to meet the need remain significant challenges in the fight against HIV/AIDS.

* The latest global HIV/AIDS estimates from UNAIDS/WHO reflect improved and expanded HIV surveillance, country data collection and methodologies, as well as an increased understanding of the natural course of the epidemic.  As a result, there have been substantial revisions from previous published estimates.  For more information on these revisions as well as other factors impacting HIV/AIDS estimates, see UNAIDS Backgrounder on Methodology.

Sources

• UNAIDS/WHO, 2008 Report on the Global AIDS Epidemic Update, July 2008
• WHO, Towards Universal Access: Scaling Up Priority HIV/AIDS Interventions in the Health Sector, Progress Report, June 2008  
• UNAIDS, Financial Resources Required to Achieve Universal Access to HIV Prevention, Treatment, Care and Support, September 2007

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