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II. Global Overview

Executive Summary

July 6, 2004

In 2003, almost five million people became newly infected with HIV, the greatest number in any one year since the beginning of the epidemic. At the global level, the number of people living with HIV continues to grow -- from 35 million in 2001 to 38 million in 2003. In the same year, almost three million were killed by AIDS; over 20 million have died since the first cases of AIDS were identified in 1981.

The epidemic varies in scale or impact within regions; some countries are more affected than others, and within countries there are usually wide variations in infection levels between different provinces, states or districts, for example.

New and Revised Estimates

The number of people living with HIV continues to grow -- from 35 million in 2001 to 38 million in 2003. The UNAIDS report highlights the latest global trends and, for the first time, features revised HIV prevalence rates for previous years, allowing for a better understanding of how the epidemic is spreading. Comparing the latest estimates with those published in previous years is misleading.

For the first time, the report compares new estimates for 2003 with revised estimates for 2001 based on improved methodologies. This is the best way we know how to obtain a more accurate picture of the AIDS epidemic. Although the new global estimates are slightly lower than the previously published estimates, the actual number of people living with HIV has not decreased, rather the epidemic continues to grow based on revised 2001 estimates.

HIV estimates -- whether they are based on household surveys or surveys of pregnant women -- need to be assessed critically as the epidemic evolves. Achieving 100% certainty about the numbers of people living with HIV globally, for example, would require repeatedly testing every person in the world for HIV -- which is logistically impossible.


The epidemic in Asia is expanding rapidly. This is most evident with sharp increases in HIV infections in China, Indonesia and Viet Nam. An estimated 7.4 million people are living with HIV in the region and 1.1 million people became newly infected last year alone -- more than any year before. Home to 60% of the world's population, the fast-growing Asian epidemic has huge implications globally.

In Asia, the HIV epidemic remains largely concentrated among injecting drug users, men who have sex with men, sex workers, clients of sex workers and their immediate sexual partners. Effective prevention coverage in these groups is inadequate, partly because of stigma and discrimination. Asian countries such as Thailand and Cambodia, which have chosen to tackle openly high-risk behaviour, such as sex work, have been more successful in fighting HIV, as shown by the reduction in infection rates among sex workers.

However there is no room for complacency. Although there is a reduction in the numbers of young Thai men visiting brothels, for example, there is also an increase in casual sex. Behavioural surveillance between 1996 and 2002 shows a clear rise in the proportion of secondary school students who are sexually active, and at the same time consistently low levels of condom use.

If other Asian countries fail to target populations at higher risk, the epidemic will affect much greater numbers of people in the general population.

India has the largest number of people living with HIV outside South Africa -- 5.1 million. But knowledge about the virus and its transmission is still scant and incomplete, and there is concern that many men who have sex with men may be infecting women with whom they also have sex.


An estimated 25 million people are living with HIV in sub-Saharan Africa. There appears to be a stabilization in HIV prevalence rates, but this is mainly due to a rise in AIDS deaths and a continued increase in new infections. Prevalence is still rising in some countries such as Madagascar and Swaziland, and is declining nationwide in Uganda.

Sub-Saharan Africa is home to just over 10% of the world's population -- and almost two-thirds of all people living with HIV. In 2003, an estimated three million people became newly infected and 2.2 million died (75% of the three million AIDS deaths globally that year).

There is no such thing as the "African" epidemic; there is tremendous diversity across the continent in the levels and trends of HIV infection. In six countries, adult HIV prevalence is below 2%, while in six other countries it is over 20%. In southern Africa all seven countries have prevalence rates above 17% with Botswana and Swaziland having prevalence above 35%. In West Africa, HIV prevalence is much lower with no country having a prevalence above 10% and most having prevalence between one and five percent. Adult prevalence in countries in Central and East Africa falls somewhere between these two groups, ranging from 4% to 13%.

African women are at greater risk, becoming infected at an earlier age than men. Today there are on average 13 infected women for every 10 infected men in sub-Saharan Africa -- up from 12 for 10 in 2002. The difference is even more pronounced among 15 to 24 year olds. A review compared the ratio of young women living with HIV to young men living with HIV; this ranges from 20 women for every 10 men in South Africa to 45 women for every 10 men in Kenya and Mali.

In North Africa and the Middle East, around 480 000 are living with HIV but systematic surveillance of the epidemic is not well developed, particularly among high-risk groups such as injecting drug users. Yet in much of the region HIV infection appears concentrated among this group. There is also concern that HIV may be spreading undetected among men who have sex with men, as male-male sex is widely condemned and illegal in many places.

Eastern Europe and Central Asia

Eastern Europe and Central Asia continue to have expanding epidemics, fuelled by injecting drug use. About 1.3 million people are living with HIV, compared with about 160 000 in 1995. Strikingly, more than 80% of them are under the age of 30. Estonia, Latvia, the Russian Federation and Ukraine are the worst-affected countries, but HIV also continues to spread in Belarus, Kazakhstan and Moldova.

The main driving force behind the epidemic in this region is injecting drug use. But in some countries sexual transmission is becoming increasingly common, especially among injecting drug users and their partners.

Russia, with over three million injecting drug users, remains one of the worst-affected countries in the region. Women account for an increasing share of newly diagnosed cases of HIV -- up from one-in-four in 2001 to just one-in-three one year later in 2003.

Latin America

Around 1.6 million people are living with HIV in Latin America. The epidemic is concentrated among populations at high risk of HIV infection -- injecting drug users and men who have sex with men.

Low national prevalence hides some serious local epidemics. For example, in Brazil (the region's most populous country), national prevalence is below 1%, but in certain cities 60% of injecting drug users are infected with HIV.

In Central America, HIV is spread predominantly through sex -- both heterosexual and among men who have sex with men.


Three Caribbean countries have national HIV prevalence rates of at least 3%: the Bahamas, Haiti, and Trinidad and Tobago. Around 430 000 people in the region are living with HIV.

The Caribbean epidemic is mainly heterosexual, and in many places it is concentrated among sex workers. But it is also spreading in the general population. The worst-affected country is Haiti where national prevalence is around 5.6%, the highest outside Africa.

High-Income Countries

An estimated 1.6 million people are living with HIV in these countries. Unlike the situation in other regions, the great majority of people living with HIV in high-income countries who need antiretroviral therapy have access to it, so they are staying healthy and surviving longer than infected people elsewhere.

The report finds that infections are on the rise in the United States and Western Europe. In the US, an estimated 950 000 people are living with HIV -- up from 900 000 in 2001. Half of all new infections in recent years have been among African Americans. In Western Europe, 580 000 people are living with HIV compared to 540 000 in 2001.

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This article was provided by UNAIDS. It is a part of the publication 2004 Report on the Global AIDS Epidemic. Visit UNAIDS' website to find out more about their activities, publications and services.