Unless averted with renewed and more effective prevention efforts, resurgent epidemics will continue to threaten high-income countries, where over 75,000 people became infected with HIV in 2001.
In Australia, Canada, the United States of America (USA) and countries of Western Europe, a pronounced rise in unsafe sex is triggering higher rates of sexually transmitted infections and, in some cases, higher levels of HIV incidence among men who have sex with men. The prospect of rebounding HIV/AIDS epidemics looms as a result of widespread public complacency and stalled, sometimes inappropriate, prevention efforts that do not reflect changes in the epidemic. In Japan, meanwhile, HIV infections are also on the rise.
The rise in new HIV infections among men who have sex with men is striking. In Vancouver, Canada, HIV incidence among young men who have sex with men rose from an average of 0.6% in 1995-1999 to 3.7% in 2000. In London, United Kingdom, reported HIV infections among gay men are also on the rise. In Madrid, reported HIV infections rose almost twofold (from 1.16% to 2.16%) in 1996-2000, whereas, in San Francisco, it rose from 1.1% in 1997 to 1.7% in 2000 and appears to be rising still, according to recent studies. Among gay men who inject drugs in that city, the infection rate climbed from 2% in 1997 to 4.6% in 2000.
Rising incidence of other sexually transmitted infections among men who have sex with men (in Amsterdam, Sydney, London and southern California, for instance) confirms that more widespread risk-taking is eclipsing the safer-sex ethic promoted so effectively for much of the 1980s and 1990s. Similar trends are being detected among the heterosexual populations of some countries, especially among young people. Diagnoses of gonorrhoea and syphilis among men and women have hit their highest levels for 13 years in England and Wales, for instance.
Part of the explanation could lie in the visibly life-saving effects of antiretroviral therapy, introduced in high-income countries in 1996. Deaths attributed to HIV in the USA, for instance, fell by a remarkable 42% in 1996-97, since when the decline has levelled off. However, this wide access to antiretroviral therapy has encouraged misperceptions that there is now a cure for AIDS and that unprotected sex poses a less daunting risk. High-risk behaviour is increasing, as a result.
Prevention efforts, as well as treatment and care strategies, have to contend with other, significant shifts in the epidemic, such as its slow but apparently inexorable shift towards other vulnerable populations. At play appears to be an overlap of racial discrimination with income, health and other inequalities.
In high-income countries there is evidence that HIV is moving into poorer and more deprived communities, with women at particular risk of infection. Young adults belonging to ethnic minorities (including men who have sex with men) face considerably greater risks of infection than they did five years ago in the USA. African-Americans, for instance, make up only 12% of the population of the USA, but constituted 47% of AIDS cases reported there in 2000. As elsewhere in the world, young disadvantaged women (especially African-American and Hispanic women) in the USA are being infected with HIV at higher rates and at younger ages than their male counterparts.
In the USA, men having sex with men is still the main mode of transmission (accounting for some 53% of new HIV infections in 2000), but almost one-third of new HIV-positive diagnoses were among women in 2000. In this latter group, an overlap of injecting drug use and heterosexual intercourse appears to be driving the epidemic. Indeed, injecting drug use has become a more prominent route of HIV infection in the USA, where an estimated 30% of new reported AIDS cases are related to this mode of transmission. In Canada, women now represent 24% of new HIV infections, compared to 8.5% in 1995.
The HIV epidemic in western and central Europe is the result of a multitude of epidemics that differ in terms of their timing, their scale and the populations they affect. Portugal faces a serious epidemic among injecting drug users. Of the 3,733 new HIV infections reported there in 2000, more than half were caused by injecting drug use and just under a third occurred via heterosexual intercourse. Reports of new HIV infections also indicate that sex between men is an important transmission route in several countries, including Germany, Greece and the United Kingdom. Unfortunately, HIV reporting data are uneven in several of the more affected countries, including some of those believed to be most affected by the epidemic among injecting drug users.
In Japan, the number of HIV infections detected in men who have sex with men has risen sharply in recent years, with male-male sex now accounting for more than twice as many infections in men as heterosexual sex. This is a major departure from past patterns: until two years ago, the number of new infections reported in both groups was roughly equal.
There are also signs that the sexual behaviour of youth in Japan could be changing significantly and putting this group at greater risk of HIV infection. Higher rates of Chlamydia among females and gonorrhoea infections among males, as well as a doubling of the number of induced abortions among teenage women in the past five years, suggest increased rates of unprotected sexual intercourse. Behavioural data, meanwhile, show low condom use, both in the general population and among sex workers.