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, 33.2 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 2.5 million people became newly infected with HIV in 2007, and more than two 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 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 fivefold since December 2003 in low- and middle-income countries, only 28% of people living with HIV/AIDS in need of ARVs were estimated to be receiving treatment as of December 2006. This represents 2.0 million of the estimated 7.1 million people in need of antiretroviral treatment in these countries. Access to prevention services also is low, with fewer than one in five people at risk of HIV infection estimated to have access in low and middle-income countries.

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 estimates that spending on HIV/AIDS rose from US$300 million in 1996 to US$8.3 billion in 2005, and is projected to reach 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 Revised HIV Estimates fact sheet.

Sources

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

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