Epidemiology of HIV/AIDS
UNAIDS and the WHO estimated that between 36 and 44 million people around the world were living with HIV in December 2004 [1]. It was estimated that during 2004, between 4.3 and 6.4 million people were newly infected with HIV and between 2.8 and 3.5 million people with AIDS died. The epidemic is not homogeneous within regions with some countries more afflicted than others. Even at the country level there are wide variations in infection levels between different areas. The number of people living with HIV continues to rise in most parts of the world, despite strenuous prevention strategies. Sub-Saharan Africa remains by far the worst-affected region, with 23.4 million to 28.4 million people living with HIV at the end of 2004. Just under two thirds (64%) of all people living with HIV are in sub-Saharan Africa, as are more than three quarters (76%) of all women living with HIV. [2] South & South East Asia are second most affected with 15%. AIDS accounts for the deaths of 500,000 children. More than 23 million people with AIDS have died since 1981. [3] [4]
Worldwide
| World region | Estimated adult prevalence of HIV infection (ages 15–49) |
Estimated adult and child deaths during 2004 |
|---|---|---|
| Sub-Saharan Africa | 6.9% to 8.3% | 2.1 to 2.6 million |
| Caribbean | 1.5% to 4.1% | 24,000 to 61,000 |
| Asia | 0.3% to 0.6% | 350,000 to 810,000 |
| Eastern Europe and Central Asia | 0.5% to 1.2% | 39,000 to 87,000 |
| Latin America | 0.5% to 0.8% | 73,000 to 120,000 |
| Oceania | 0.1% to 0.3% | fewer than 1,700 |
| Middle East and North Africa | 0.1% to 0.7% | 12,000 to 72,000 |
| North America, Western and Central Europe | 0.3% to 0.6% | 15,000 to 32,000 |
Source: UNAIDS and the WHO 2004 estimates. The ranges define the boundaries within which the actual numbers lie, based on the best available information. [5]
North America, Western and Central Europe
In Western countries, AIDS cases have fallen to levels not seen since the original outbreak; many attribute this trend to aggressive educational campaigns, screening of blood transfusions and increased use of condoms.
In some cities, however, there are young urban gay men of African descent as well as a good majority of African-American communities where infection rates began to show dangerous signs of rising levels for the 1990s. In the United Kingdom the number of people diagnosed with HIV increased 26% for 2000 to 2001. In the United States, blacks make up about 47% of the total HIV-positive population, yet also make up more than half of new HIV cases, despite making up only 12% of the population. In addition, if you are a black woman you are 19 times more likely to contract HIV than a white woman [6]. Experts attribute this to "AIDS fatigue" among younger people who have no memory of the worst phase of the epidemic in the 1980s, as well as "condom fatigue" among those who have grown tired of and disillusioned with the unrelenting safer sex message. This trend is of major concern to public health workers. AIDS continues to be a problem with illegal sex workers and injection drug users. On the other hand, the death rate from AIDS in all Western countries has fallen sharply, as new AIDS therapies have proven to be an effective (if expensive) means of suppressing HIV.
In the United States in particular, a new wave of infection is being blamed on the use of methamphetamine, known as Crystal meth. Research presented at the 12th Annual Retrovirus Conference in Boston in February 2005 concluded that using Crystal meth or cocaine is the biggest single risk factor for becoming HIV+ among US gay men, contributing 29% of the overall risk of becoming positive and 28% of the overall risk of being the receptive partner in bareback sex [7]. In addition, several renowned clinical psychologists now cite Crystal as the biggest problem facing gay men today, including Michael Majeski, who reckons meth is the catalyst for at least 80% of seroconversions currently occurring across the United States, and Tony Zimbardi, who calls Crystal the number one cause of HIV transmission, and says that high rates of new HIV infection are not being found among non-Crystal users. In addition, various HIV and STD clinics across the United States report anecdotal evidence that 75% of new HIV seroconversions they deal with are Crystal-related; indeed, in Los Angeles, Crystal is regarded as the main cause of HIV seroconversion among gay men in their late thirties[8]. The First National Conference on Methamphetamine, HIV and Hepatitis will be held in Salt Lake City in August of 2005.
Sub-Saharan Africa
Sub-Saharan Africa remains the hardest-hit region, with extremely high HIV prevalence among pregnant women aged 15–24 reported in a number of countries. The widespread prevalence of sexually transmitted diseases, the practice of scarification, transfusion, and the poor state of hygiene and nutrition in Africa may all be facilitating factors in the transmission of HIV-1 in this region (Bentwich et al., 1995). In 2000, the World Health Organization estimated that 25% of the units of blood transfused in Africa were not tested for HIV, and that 5–10% of HIV infections in Africa were transmitted via blood [9].
Poor economic conditions (leading to the use of dirty needles in healthcare clinics) and lack of sex education contribute to high rates of infection. In some African countries, 25% or more of the working adult population is HIV-positive; in Botswana the figure was 35.8% (1999 estimate World Press Review), the highest reported infection rate in the world.
In South Africa, where President Thabo Mbeki denies that HIV is the cause of AIDS, the government does not require that AIDS cases be reported or collect information on the number of South Africans with AIDS. UNAIDS estimates that at the end of 2003 there were 5.3 million people in South Africa living with HIV — 21.5% of the population[10].
Although HIV infection rates are much lower in Nigeria than in other African countries, the size of Nigeria's population meant that by the end of 2003, there were an estimated 3.6 million people living with HIV[11]. On the other hand, Uganda, Zambia, Senegal, and most recently Botswana have begun intervention and educational measures to slow the spread of HIV, and Uganda has succeeded in actually reducing its HIV infection rate[12].
Latin America and the Caribbean
Latin America and the Caribbean had just over 2.2 million infected persons in 2003, with modes of transmission and infection rates varying widely. The infection rates are highest in Central America and the Caribbean, where heterosexual transmission is fairly common. In Mexico, Brazil, Colombia and Argentina, drug injection and homosexual activity are the main modes of transmission, but there is concern that heterosexual activity may soon become a primary method of spreading the virus. Brazil recently began a comprehensive AIDS prevention and treatment programme to keep AIDS in check, including the production of generic versions of anti-retroviral drugs.
Asia
AIDS infection rates are also rising steadily in Asia, with over 7.5 million infections by 2003. In Asia, the HIV epidemic remains largely concentrated in injecting drug users, men who have sex with men, sex workers, and clients of sex workers and their immediate sexual partners. Effective prevention strategies in these populations are, for the most part, inadequate.
In July 2003, the estimated number of HIV+ individuals in India was about 4.6 million, roughly 0.9% of the working adult population. In China, the number was estimated at 1 million to 1.5 million, with some estimates going much higher. China also suffers from an epidemic in some of its rural areas, where large numbers of farmers, especially in Henan province, participated in sloppy procedures for blood transfusions; estimates of those infected are in the tens of thousands. AIDS seems to be under control in Thailand and Cambodia, but new infections occur in those nations at a steady rate.
Eastern Europe and Central Asia
There is also growing concern about a rapidly growing epidemic in Eastern Europe and Central Asia, where an estimated 1.7 million people were infected by January 2004. The rate of HIV infections rose rapidly from the mid-1990s, due to social and economic collapse, increased levels of intravenous drug use and increased numbers of prostitutes. By 2004 the number of reported cases in Russia was over 257,000, according to the World Health Organization, up from 15,000 in 1995 and 190,000 in 2002; some estimates claim the real number is up to five times higher, over 1 million. There are predictions that the infection rate in Russia will continue to rise quickly, since education there about AIDS is almost non-existent. Ukraine and Estonia also had growing numbers of infected people, with estimates of 500,000 and 3,700 respectively in 2004.
