HIV/AIDS
Situation
Global and regional highlights
Mirrored from:
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HIV/AIDS Situation Global and regional highlights |
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People living |
Adults male female Children Total |
21 million 12.2 million 8.8 million 800,000 21.8 million |
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HIV/AIDS-associated |
Adults male female Children Total |
600,000 400,000 300,000 1.3 million 1.9 million |
| Cumulative HIV infections |
Adults male female Children Total |
25.5 million 14.9 million 10.5 million 2.4 million 27.9 million |
| Cumulative AIDS cases |
Adults male female Children Total |
6.1 million 3.5 million 2.6 million 1.6 million 7.7 million |
| Cumulative HIV/AIDS deaths |
Adults male female Children Total |
4.5 million 2.6 million 1.9 million 1.3 million 5.8 million |
| Because of rounding, figures may not tally. |
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By 30 June 1996, 1,393,649 cumulative cases of AIDS in adults and children had been officially reported by countries - an increase of approximately 19% over the 1,169,811 cases reported by 30 June 1995. However, taking into account under-recognition, unde r-reporting and reporting delays, it is estimated that more than 7.7 million AIDS cases have actually occurred since the start of the global HIV/AIDS epidemic* (Figure 1).
* Also know as the HIV/AIDS pandemic. A more appropriate indication of the trends in the global epidemic is the number of new infections with the human immunodeficiency virus (HIV), which causes AIDS. According to UNAIDS estimates, over 3.1 million new HIV infections are expected to occur dur ing 1996, or more than 8,500 a day - 7,500 adults and 1,000 children. During 1995 HIV/AIDS-associated illnesses caused the death of 1.3 million people, including 300,000 children below the age of five. Since the start of the global epidemic, around 28 million people have been infected with HIV (Figure 2) - 25.5 million adults and 2.4 million children. Of these, an estimated 4.5 million adults and 1.3 million children have died. Today, 21.8 million people are estimated to be living with HIV/AIDS (Figure 3). Of these, 21 million are adults and 830,000 are children. Approximately 42% of the 21 million adults living with HIV/AIDS are women and the proportion is growing. The majority of newly infected adults are between 15 and 24 years old.
Worldwide, between 75 and 85 of every 100 HIV infections in adults have been transmitted through unprotected sexual intercourse.** Heterosexual (male-female) intercourse accounts for more than 70% of all adult HIV infections to date and homosexual (male-m ale) intercourse for a further 5-10%.
** Sexual intercourse without a condom. Transfusion of HIV-infected blood or blood products accounts for 3-5% of all adult HIV infections. In many parts of the world HIV transmission through the transfusion of infected blood has been reduced by the use of voluntary blood donors, the routine scr eening of donated blood for HIV, and through a more rational use of blood aimed at reducing the number of transfusions. The sharing of HIV-infected injection equipment by drug users accounts for 5-10% of all adult HIV infections. This proportion is growing. In many areas of the world, injecting drug use is the dominant mode of transmission. Mother-to-child (vertical) transmission accounts for more than 90% of all infections in infants and children. Around 25-35% of all infants born to HIV-infected women themselves become infected with HIV before or during birth, or through breast-feeding. St udies conducted in industrialized countries have shown that the administration of antiretroviral drugs to HIV-infected pregnant women and their newborn babies decreases the risk of vertical transmission by two-thirds. However, these drugs are expensive an d difficult to deliver, which puts them beyond the reach of most women living with HIV. Studies to date, primarily from industrialized countries, indicate that about 60% of adults will progress to AIDS within 12-13 years of becoming infected with HIV. Few data are available beyond 12 years, but it is expected that the vast majority of HIV-in fected persons will eventually develop AIDS. Although no long-term cohort studies have been completed, progression from initial HIV infection to the onset of AIDS might be more rapid in developing countries. A more rapid progression would result in a high er estimate of the number of AIDS cases. Survival after the onset of AIDS has been increasing in industrialized countries from an average of less than 1 year to about 3 years at present. Survival time with AIDS in developing countries remains short and is estimated to be less than 1 year. Longer survival appears to be directly related to routine treatment with antiretroviral drugs, the use of drugs for opportunistic infections, and a better overall quality of health care. The majority of AIDS cases occur before age 35, and over 90% of all AIDS deaths occur in people under the age of 50. |
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Basing its HIV/AIDS estimations and projections on assumptions very similar but not identical to those applied by UNAIDS and WHO, the François-Xavier Bagnoud Center for Health and Human Rights of the Harvard University School of Public Health estimates that by 1 July 1996, worldwide, about 3 million children had acquired HIV infection through mother-to-child transmission since the beginning of the global epidemic. Because of the rapid progression of paediatric HIV infection to the onset of AIDS and the short survival once paediatric AIDS has set in, most of these children have already died. About one quarter of all AIDS-related deaths thus far have been in children who were infected vertically. To date, over 85% of all children infected through mother-to-child transmission have been in sub-Saharan Africa. During 1995, approximately 500,000 children were born with HIV infection (about 1,400 per day); of these children, 67% were in sub-Saharan Africa, 30% in South-East Asia, 2% in Latin America, and 1% in the Caribbean. As of July 1996, about 1 million children are living with HIV/AIDS, of whom 65% are in sub-Saharan Africa. HIV incidence among children in sub-Saharan Africa, South-East Asia, and the Caribbean is higher than HIV incidence among adults in all other regions of the world. HIV/AIDS prevalence among children is almost 35 times higher in the developing world than in the industrialized world. The HIV/AIDS epidemic also affects children through the premature death of their parents. One in every three children orphaned by HIV/AIDS is younger than 5 years old. Since the beginning of the global epidemic, over 9 million children under the age of 15 have lost their mother to HIV/AIDS. Of these maternal orphans, 90% have been in sub-Saharan Africa. |
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The acquired immunodeficiency syndrome (AIDS) was first recognized in 1981 among homosexual men in the United States of America. The human immunodeficiency virus (HIV) - the virus that causes AIDS - was identified in 1983. Extensive spread of HIV appears to have begun in the late 1970s and early 1980s among men and women with multiple sexual partners in East and Central Africa and among homosexual and bisexual men in certain urban areas of the Americas, Australasia, and Western Europe. Today, the virus is being transmitted in all countries. Two major types of HIV have been recognized, HIV-1 and HIV-2. HIV-1 is the dominant type worldwide. HIV-2 is found principally in West Africa but cases have been reported from East Africa, Europe, Asia and Latin America. There are at least 10 different genetic subtypes of HIV-1, but their biological and epidemiological significance is unclear at present. Both HIV-1 and HIV-2 are transmitted in the same ways. • The main route is through unprotected sexual intercourse between man and woman (heterosexual) or between men (homosexual). There are no documented cases of sexual transmission between women. • HIV is also transmitted through blood, blood products, and donated organs or semen. Bloodborne transmission occurs primarily through the use of inadequately sterilized needles, syringes or other skin-piercing instruments, and the transfusion of infected blood. • Finally, the virus may be transmitted from an infected mother to her fetus or infant during pregnancy or delivery, or when breast-feeding. This is known as mother-to-child, or vertical, transmission. While the routes of transmission are the same, HIV-2 appears to be less easily transmitted than HIV-1 and the progression from HIV-2 infection to AIDS appears to be slower than in the case of HIV-1. AIDS seems clinically indistinguishable whether it results from HIV-1 or HIV- 2. AIDS is late-stage HIV infection characterized by a severely weakened immune system which can no longer ward off life-threatening opportunistic infections and cancers.
There are wide variations in HIV prevalence throughout the world (Figure 4). More than 90% of all adults with HIV infection or AIDS live in developing countries (Figure 5). Countries in sub-Saharan Africa and the Caribbean have the highest national rates of adult HIV prevalence.* At the end of 1994, adult prevalence ranged from approximately 1 per 100,000 (0.001%) in the Central Asian Republics and the Democratic People’s Re public of Korea to more than 10% in five African countries (Botswana,18%; Zambia and Zimbabwe, 17%; Uganda, 15%; Malawi,13%). Part of this disparity can be attributed to the maturity of the epidemic in Africa and the more recent introduction of HIV into C entral and East Asia.
Most of the epidemiological evidence indicates that the extensive spread of HIV in sub-Saharan Africa began in the mid to late 1970s. * Defined as the number of adults aged 15-49 years living with HIV/AIDS divided by the total number in that age group. Currently, an estimated 13.3 million adults are HIV-infected (over 5% of all people aged 15-49 in sub-Saharan Africa). More than three-fifths of all adults living with HIV/AIDS worldwide are in this region. Adult HIV prevalence rates in sub-Saharan Africa range from approximately 1 per 1000 (0.1%) in the Comoros to more than 18% in Botswana. Women account for slightly more than half of all infected adults.
The United Nations now incorporates the demographic impact of HIV/AIDS into its popula-tion estimates and forecasts. In 1995 the Population Division of the Department for Econo-mic and Social Information and Policy Analysis of the United Nations Secretari at examined the demographic impact of HIV/AIDS in 15 sub- Saharan African countries with a 1994 HIV prevalence of more than 1% in the adult (age 15-49) population. Below that level of prevalence, the epidemic's impact on the national demographic picture i s insignificant. Population size: In 1995, because of HIV/AIDS, the combined population of all 15 coun-tries will be 2 million smaller than expected (221.2 million people versus 223.4 million). In the year 2005 it will be 11.6 million smaller (291.8 million versus 303.4 m illion). Number of deaths: In 1990-1995, HIV/AIDS accounted for 1.7 million of the total 15.8 million deaths in these 15 countries. Life expectancy at birth: In 1990-1995, HIV/AIDS decreased life expectancy at birth in these 15 countries from 52.8 to 49.6 years. In 2000-2005 life expectancy without AIDS would have been 57.1 years. HIV/AIDS will reduce this by more than 7 years, to 49. 6 years. The majority of the world's children with HIV/AIDS live in sub-Saharan Africa. In this region, the average age of infection and onset of AIDS is younger than the global average. Almost 90% of adult AIDS cases occur before the age of 40. Cases in women occur about 4years earlier than in men, possibly reflecting infection at an earlie r age. Heterosexual transmission accounts for the majority of infections in the area, while transmission through blood transfusions accounts for up to 10% of infections.
Despite the fact that the spread of HIV began in this area only in the mid 1980s, there are already more than 4.7 million adults living with HIV/AIDS, or 5 for every 1000 adults (0.5%). Because of the large populations of countries such as India and Indon esia, this region accounts for more than a fifth of all global adult HIV infections. Over 90% of the HIV-infected adults in South and South-East Asia live in India, Thailand, Myanmar and Cambodia. With estimated adult infections exceeding 3 million, India is the country with the largest number of HIV-infected adults in the world, even though adult prevalence has not yet reached 1%. Thailand has the highest prevalence, with slightly more than 2% of the adult population infected. Cambodia and Myanmar have adult prevalence rates approaching 2%. Around a third of all infected adults are women. The predominant route of transmission is heterosexual intercourse; second in importance is injecting drug use.
Extensive HIV spread in this area most likely began in the late 1970s or early 1980s. Overall adult prevalence is slightly more than 5 infections per 1,000 adults (0.5%). Almost 1.3 million adults live with HIV/AIDS in this area, or 6% of the global total. National adult prevalence rates range from 6 per 1,000 (0.6%) in Bolivia to over 2% in Belize. Brazil and Mexico together account for more than 7 out of 10 infections in Latin America. Early in the epidemic, most HIV infections occurred among homosexual and bisexual men. Today there are increasing levels of transmission through heterosexual intercourse and the sharing of contaminated drug injection equipment. In Latin America 18% of infections are in women; this proportion is rising as heterosexual transmission becomes more prominent. Although the Caribbean with more than 250,000 HIV infections in adults accounts for only 1% of the current global total, the adult prevalence is second only to that of sub-Saharan Africa: out of every 1,000 adults, 14 are living with HIV/AIDS (1.4%). Heterosexual transmission has predominated since the beginning of the epidemic in the late 1970s. More than 40% of all HIV-infected adults in the Caribbean are women. The most severely affected countries are Haiti, with an adult prevalence of 4%, and Barbados, with an adult prevalence approaching 4%. Together Haiti and the Dominican Republic account for more than 85% of all Caribbean infections. Cuba has the lowest prevalence rate in the region (2 infections for every 10,000 adults, or 0.02%). Industrialized countries of North America, Western Europe and Australasia More than 1.2 million adults in these countries are living with HIV/AIDS; they account for 6% of the global total. Adult HIV prevalence rates range from 12 HIV infections per 10,000 (0.12%) in Australasia, through 2 per 1,000 (0.2%) in Western Europe, to 5 per 1,000 (0.5%) in North America. In the early 1980s homosexual intercourse dominated as the mode of transmission in these countries. Today, HIV infections acquired through the sharing of drug injection equipment and through heterosexual intercourse are playing an increasingly important role in the epidemic. In some countries, over 75% of AIDS cases are related to drug injecting or heterosexual contact with a drug injector. In North Africa and the Middle East there are an estimated 192,000 adults living with HIV/AIDS, giving a prevalence rate of 12 HIV infections per 10,000 adults (0.12%). While injecting drug use plays a role in some parts of the region, the dominant mode of transmission appears to be heterosexual intercourse. This region, with an estimated 29,000 HIV-infected adults, has an overall adult prevalence of 15 per 100,000 (0.015%). However, there is evidence of rapid spread of HIV, particularly in Ukraine and Poland. |
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Following several years of low but slowly rising levels of HIV infection, an outbreak has occurred among injecting drug users in Ukraine. In January 1995 1.4% of drug users were HIV positive. By August 1995 the prevalence had increased almost ten-fold, to 13%. It has now reached 55% in Nikolayev, with rates in four other cities ranging from 4.2% to 12.1%. Similar increases are expected in other Ukrainian cities, in other groups, and in neighbouring countries. |
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Epidemiological evidence indicates that widespread transmission of HIV in East Asia and the Pacific began only recently. Partly for this reason, there are now fewer than 50,000 adults living with HIV/AIDS. Given the huge adult populations of this region, which includes China, the overall prevalence is less than 4 HIV infections per 100,000 adults (0.004%). In a number of industrialized countries, in parts of sub- Saharan Africa, and among some populations in Thailand, HIV prevalence appears to be decreasing or stabilizing. In the USA about 40,000 new infections now occur annually, down from 100,000 a few years ago. Among women attending selected antenatal clinics in Uganda and among Thai military recruits, HIV prevalence has dropped. New infections are also declining in Australia, New Zealand, and some northern European countries. There is growing evidence that behavioural changes such as increased condom use, reduction in the number of sex partners, and later initiation of sexual activity contribute to these hopeful trends. The risk of HIV transmission through sexual intercourse is significantly higher in the presence of other sexually transmitted diseases (STD) such as syphilis or gonorrhoea in one or both partners. It has now been confirmed that early detection and treatment of other STDs can reduce HIV transmission. In a recent study in Tanzania, 12 communities with AIDS prevention programmes were followed for two years. In six of them STD prevention and care were improved by establishing an STD reference clinic, ensuring regular supply of antibiotics, training peripheral health workers, and providing clients with health education about STDs. At the conclusion of the study, it was found that the six communities with improved STD control had 40% fewer new HIV infections than the other communities. In Viet Nam, condom distribution rose from 40 million in 1991 to 117 million in 1995. In 1995, 20 of the 117 million were distributed as a result of a dynamic HIV/STD condom social marketing campaign. In Thailand, condom distribution rose steeply from 15 million in 1990 to 88 million in 1992, a six-fold increase over a period of three years. In Ethiopia the number of condoms distributed rose markedly from 20,000 in 1987 to over 26 million in 1993. In Africa as a whole, demand for condoms has risen greatly since 1988, when less than 1million were sold; in 1994 110 million condoms were sold by one social marketing firm alone. Concurrent with the rise in the number of condoms distributed worldwide, there has been an increase in reported condom use. For example, in Thailand between 1989 and 1994, condom use rose from 14% to over 90% of all commercial sex acts. In Ghana consistent condom use among sex workers rose from 6% to 71% in 6 months. In Switzerland, a survey of sexually active 17-20 year olds showed that the proportion always using condoms increased from 19% to 73% between 1987 and 1990. and UNAIDS EstimatesBoth the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the François-Xavier Bagnoud Center for Health and Human Rights of the Harvard School of Public Health make estimates of the magnitude and trends of the global HIV/AIDS pandemic. Both sets of estimates are based on similar data and comparable methods. National estimates of HIV prevalence are based on HIV seroprevalence studies. If no relevant data are available a national estimate is made based on data from countries sharing similar epidemiological characteristics. These national prevalence estimates are then aggregated to produce regional estimates which are used to locate the current status of the epidemic along a theoretical epidemic curve. AIW II and UNAIDS differ slightly on two assumptions: 1. While UNAIDS assumed a 10-year median progression from HIV to AIDS for all regions, AIW II used three different progression rates: a 7-year median progression for sub- Saharan Africa, a slightly longer one for developing countries outside of sub-Saharan Africa, and a 10-year median progression for developed countries. 2. UNAIDS assumes that the incidence of HIV in South and South-East Asia follows a linear curve while AIW II applies an exponential curve. As a result UNAIDS estimates 7,500 new adult infections a day during 1996 while AIW II estimates 11,500 new adult infections daily. These two assumptions combine to produce more AIDS adult cases (an additional 2.8 million) and adult deaths associated with HIV/AIDS (3.2 million more) in the AIW II estimations despite the small difference (1.3 million) in the estimates of the number of adults living with HIV/AIDS. |
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People living |
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AIDS in the World II 30,000,000 8,900,000 7,700,000 22,300,000 |
UNAIDS 25,500,000 6,090,000 4,480,000 21,000,000 |
Because of rounding, figures may not tally. |
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UNAIDS and WHO are pleased to acknowledge the collaboration of the following partners in the preparation of this Fact Sheet: International Program Center, U.S. Bureau of the Census; François-Xavier Bagnoud Center for Health and Human Rights of the Harvard School of Public Health; WHO European Collaborating Centre for the Epidemiological Surveillance of AIDS; UN Population Divis ion; DKT Viet Nam; AIDSCAP; and national AIDS programmes. * AIDS in the World II, The Global AIDS Policy Coalition, J Mann & D Tarantola, ed., Oxford University, in press. |
