AIDS status & challenges of the epidemic

2. What are the worldwide trends in the HIV/AIDS epidemic?

• 2.1 How many people are affected worldwide?
• 2.2 How has the epidemic evolved in heavily affected regions?
• 2.3 How has the epidemic evolved in less affected regions?

2.1 How many people are affected worldwide?

The source document for this Digest states:

An estimated 38.6 million [33.4 million–46.0 million] people worldwide were living with HIV at the end of 2005. An estimated 4.1 million [3.4 million–6.2 million] became newly infected with HIV and an estimated 2.8 million [2.4 million–3.3 million] lost their lives to AIDS. Overall, the HIV incidence rate (the proportion of people who have become infected with HIV) is believed to have peaked in the late 1990s and to have stabilized subsequently, notwithstanding increasing incidence in several countries.

Favourable trends in incidence in several countries are related to changes in behaviour and prevention programmes. Changes in incidence along with rising AIDS mortality have caused global HIV prevalence (the proportion of people living with HIV) to level off
(see Figure 2). However, the numbers of people living with HIV have continued to rise, due to population growth and, more recently, the life-prolonging effects of antiretroviral therapy. In sub-Saharan Africa, the region with the largest burden of the AIDS epidemic, data also indicate that the HIV incidence rate has peaked in most countries. However, the epidemics in this region are highly diverse and especially severe in southern Africa, where some of the epidemics are still expanding.

Box: Improving HIV surveillance data

Source & ©: UNAIDS  Report on the global AIDS epidemic: Executive summary, (2006),
The global epidemic today, p.6

For more information on this question, see:
 Chapter 02 Overview of the global AIDS epidemic, p.8,
of the full 2006 Report on the global AIDS epidemic  by UNAIDS

2.2 How has the epidemic evolved in heavily affected regions?

The source document for this Digest states:

Among the notable new trends are the recent declines in national HIV prevalence in two sub-Saharan African countries (Kenya and Zimbabwe), urban areas of Burkina Faso, and similarly in Haiti, in the Caribbean, alongside indications of significant behavioural change—including increased condom use, fewer partners and delayed sexual debut. In the rest of sub-Saharan Africa, the majority of epidemics appear to be levelling off—but at exceptionally high levels in most of southern Africa.

Source & ©: UNAIDS  Report on the global AIDS epidemic: Executive summary, (2006),
The global epidemic today, p.6

Africa remains the global epicentre of the AIDS pandemic. South Africa’s AIDS epidemic—one of the worst in the world—shows no evidence of a decline. Based on its extensive antenatal clinic surveillance system, as well as national surveys with HIV testing and mortality data from its civil registration system, an estimated 5.5 million [4.9 million–6.1 million] people were living with HIV in 2005. An estimated 18.8% [16.8%–20.7%] of adults (15–49 years) were living with HIV in 2005. ¹

¹ UNAIDS’ HIV prevalence estimates describe the percentage of adult men and women (15–49 years) living with HIV nationally. These estimates incorporate a variety of HIV data, including those gathered in household HIV surveys and at antenatal clinics. Antenatal clinic HIV data, meanwhile, reflect only HIV prevalence in pregnant women who use public antenatal facilities. Comparisons between these two sources of data have shown that antenatal clinic–based HIV estimates tend to be higher than those based on household HIV surveys.

Almost one in three pregnant women attending public antenatal clinics were living with HIV in 2004 and trends over time show a gradual increase in HIV prevalence.

Estimated number of people living with HIV, and adult HIV prevalence, globally and in sub-Saharan Africa, 1985-2005

There are no clear signs of declining HIV prevalence elsewhere in southern Africa—including in Botswana, Namibia and Swaziland, where exceptionally high infection levels continue. In Swaziland, national adult HIV prevalence is estimated at 33.4% [21.2%–45.3%]. HIV prevalence among pregnant women attending antenatal clinics rose from 4% in 1992 to 43% in 2004. Botswana’s epidemic is equally serious, with national adult HIV prevalence estimated at 24.1% [23.0%–32.0%] in 2005. Lesotho’s epidemic seems to be relatively stable at very high levels, with an estimated national adult HIV prevalence of 23.2% [21.9%–24.7%]. On the eastern coastline, a dynamic epidemic is underway in Mozambique, where the estimated national adult HIV prevalence is 16.1% [12.5%–20.0%]. HIV is spreading fastest in provinces linked by major transport routes to Malawi, South Africa and Zimbabwe.

Source & ©: UNAIDS  Report on the global AIDS epidemic: Executive summary, (2006),
The global epidemic today, p.6

The Caribbean’s epidemics—and countries’ AIDS responses—vary considerably in extent and intensity. HIV infection levels have decreased in urban parts of Haiti and in the Bahamas and have remained stable in neighbouring Dominican Republic and Barbados. As well, expanded access to antiretroviral treatment in the Bahamas and Barbados appears to be reducing AIDS deaths. However, such progress has not been enough to undo the Caribbean’s status as the second-most affected region in the world. AIDS is the leading cause of death among adults (15–44 years) and claimed an estimated 27 000 [18 000–37 000] lives in 2005. Overall, less than one in four (23%) persons in need of antiretroviral therapy was receiving it in 2005. ⁵

⁵ WHO/UNAIDS (2006). Progress on global access to HIV antiretroviral therapy: a report on “3 by 5” and beyond. WHO/UNAIDS, Geneva]. National adult HIV prevalence exceeds 2% in Trinidad and Tobago, and 3% in the Bahamas and Haiti.

Source & ©: UNAIDS  Report on the global AIDS epidemic: Executive summary, (2006),
The global epidemic today, p.9

For more information on this question, see:
 Chapter 02 Overview of the global AIDS epidemic, p.8 and
 Chapter 7 Treatment and care, Expanding access to antiretroviral Drugs, p.151,
of the full 2006 Report on the global AIDS epidemic  by UNAIDS

2.3 How has the epidemic evolved in less affected regions?

The source document for this Digest states:

HIV prevalence has also been declining in four states in India, including Tamil Nadu, where prevention efforts were scaled up in the late 1990s. In Cambodia and Thailand, steady ongoing declines in HIV prevalence are continuing. However, HIV prevalence is increasing in some countries, notably China, Indonesia, Papua New Guinea and Viet Nam and there are signs of HIV outbreaks in Bangladesh and Pakistan.

Source & ©: UNAIDS  Report on the global AIDS epidemic: Executive summary, (2006),
The global epidemic today, p.6

Latest estimates show some 8.3 million [5.7 million–12.5 million] people (2.4 million among adult women [1.5 million–3.8 million]) were living with HIV in Asia at the end of 2005— more than two-thirds of them in one country, India. In Asia, about one in six people (16%) in need of antiretroviral treatment are now receiving it. While progress has been strongest in Thailand, coverage still remains well below 10% in India (which has more than 70% of the region’s total treatment need). Expanded HIV surveillance and improved estimation methods are enabling a clearer picture of the AIDS epidemic in China. Approximately 650 000 [390 000–1.1 million] people in China were living with HIV in 2005. ³ Injecting drug users (of whom there are at least one million registered in the country) account for almost half (44%) the people living with HIV. The overlapping risks of injecting drug use and unprotected sex feature in several other epidemics in Asia. ⁴ An example is Viet Nam, where HIV has spread into all 59 provinces and all cities. In 2005, an estimated 360 000 [200 000–570 000] adults and children were living with HIV in Myanmar, and national adult HIV prevalence stood at 1.3% [0.7%–2%].The HIV epidemics remain relatively limited in Bangladesh, the Philippines, Indonesia and Pakistan, although each of these countries risks a more serious epidemic if prevention methods are not improved. An especially troubling situation has emerged in the easternmost province of Papua, which borders on Papua New Guinea, where a serious HIV epidemic is underway.

³ Ministry of Health China (2006). 2005 update on the HIV/AIDS epidemic and response in China. Beijing, Ministry of Health China, UNAIDS, WHO.

⁴ Monitoring the AIDS Pandemic Network (MAP) (2005a). Drug injection and HIV/AIDS in Asia—MAP Report 2005. July. MAP, Geneva

The epidemics in eastern Europe and central Asia continue to expand. Some 220 000 [150 000–650 000] people were newly infected with HIV in 2005, bringing to about 1.5 million [1.0 million–2.3 million] the number of people living with HIV—a twenty-fold increase in less than a decade. The epidemic’s death toll is rising sharply, too. AIDS killed an estimated 53 000 [36 000–75 000] adults and children in 2005—almost twice as many as in 2003. Increasingly large numbers of women are being infected with HIV. The majority of people living with HIV in eastern Europe and central Asia are in two countries: the Ukraine, where the annual number of new HIV diagnoses keeps rising, and the Russian Federation, which has the biggest AIDS epidemic in all of Europe.

Source & ©: UNAIDS  Report on the global AIDS epidemic: Executive summary, (2006),
The global epidemic today, p.8

In Latin America, some 140 000 [100 000–420 000] people were newly infected with HIV in 2005, bringing to 1.6 million [1.2 million–2.4 million] the number of people living with the virus. The region’s biggest epidemics are in the countries with the largest populations, notably Brazil, which is home to more than one-third of the people living with HIV in Latin America. The most intense epidemics, however, are underway in the smaller countries of Belize and Honduras, in each of which more than 1.5% or more of adults were living with HIV in 2005. While notable gains in access to HIV treatment have been made in contrast countries such as Argentina, Brazil, Chile, Costa Rica, Mexico, Panama, Uruguay and Venezuela, the poorest countries of Central America and those in the Andean region of South America are struggling to expand treatment access in the face of affordability barriers. ⁶

⁶ PAHO (2005). Care fact sheets. Pan American Health Organization, Washington

Except for Sudan, national adult HIV prevalence in the countries of the Middle East and North Africa is very low, and does not exceed 0.1%. However, available data suggest that the epidemics are growing in several countries—including in Algeria, Islamic Republic of Iran, Libyan Arab Jamahiriya and Morocco. Across the region, an estimated 64 000 [38 000–210 000] people were newly infected with HIV in 2005, bringing the total number of people living with the virus to some 440 000 [250 000–720 000]. Sudan accounts for fully 350 000 [170 000–580 000] of those people.

While HIV infection levels remain low across Oceania, Australia’s long-established AIDS epidemic is not dissipating, while Papua New Guinea’s relatively young but already serious epidemic accounts for more than 90% of all HIV infections reported in Oceania to date outside of Australia and New Zealand.

Meanwhile, evidence continues to emerge of resurgent epidemics in the United States of America and in some countries of Europe among men who have sex with men, and of largely hidden epidemics among their counterparts in Latin America and Asia.

Source & ©: UNAIDS  Report on the global AIDS epidemic: Executive summary, (2006),
The global epidemic today, p.9

For more information on this question, see:
 Chapter 02 Overview of the global AIDS epidemic, p.9,
of the full 2006 Report on the global AIDS epidemic  by UNAIDS