The Lancet, UK 18/06/2008
Kevin M De Cock - Department of HIV/AIDS, WHO, Geneva 1211, Switzerland
Paul De Lay - Department of Evidence, Monitoring, & Policy, UNAIDS, Geneva, Switzerland
Recent debates about trends in HIV infections have overshadowed genuine achievements in addressing the pandemic.1 WHO, UNAIDS, and UNICEF have recently issued a series of reports that assess progress towards universal access to HIV prevention, treatment, and care.2,3 Leaders of the G8 countries had committed to this ambitious goal in Gleneagles, UK, in 2005 and in the political declaration made at the UN General Assembly.4,5 On the basis of data from 143 countries, by the end of 2007, almost 3 million people in low-income and middle-income countries were being maintained on antiretroviral therapy—1 million more than the previous year. Almost three-quarters of the individuals on therapy lived in sub-Saharan Africa, where measurable reductions in AIDS mortality are occurring, and 200 000 were children. Treatment coverage globally was estimated at 31%; the total estimated need for therapy under current treatment recommendations6 is 9·7 million people.
Coverage for antiretrovirals in HIV-positive pregnant women for prevention of mother-to-child transmission in low-income and middle-income countries increased from 9% in 2004 to 34% in 2007. In such countries, the percentage of young people having sex before age 15 years is decreasing in all regions, a continuation of trends detected earlier this decade.
Despite these gains, huge gaps in access remain. Only 20% of people with HIV in low-income and middleincome countries are aware of their infection status. Surveys indicate that 40% of men and 38% of women at ages 15–24 years had accurate and comprehensive knowledge about HIV and about how to avoid transmission. In countries with epidemics that are concentrated within the populations most at risk, HIV prevention programmes fail to reach many people at risk of acquiring HIV, including most men who have sex with men and injecting drug users.
Focusing scale-up of services where they are needed requires "knowing your epidemic", globally and locally.7 According to the 2007 UNAIDS/WHO AIDS epidemic update,8 at the end of 2007, 33·2 million people(range 30·6–36·1) were living with HIV. Some 2·5 million people became newly infected that year, and 2·1 million died of AIDS. AIDS remains the leading cause of death in Africa. These latest estimates refl ect expanded sets of data, including the use of population-based surveys, and improved methods of analysis, and are better than nearly all other estimates for other global health problems.
Sub-Saharan Africa, with two-thirds of those living with HIV, has seen self-sustaining HIV epidemics with very high levels of HIV prevalence in the general population of many countries. In most of the rest of the world, HIV has occurred in concentrated epidemics that aff ect specifi c groups at risk (men who have sex with men, injecting drug users, female commercial sex workers) and their partners. The recent Report of the Commission on AIDS in Asia9 supports the concept of predominantly concentrated epidemics in that populous region.
Compartmentalising the world into concentrated and generalised epidemics usefully conveys likely trends, yet incompletely captures the complexity and heterogeneity of the epidemic. The probability of heterosexual HIV spread is infl uenced by local HIV prevalence, sexual networks, rates of partner change, and types of partner selected. Risk of heterosexual acquisition of HIV varies enor mously internationally, though even very low risk is not zero risk.
It is this complexity around the likelihood and extent of heterosexual HIV transmission that is at the root of extreme claims in the mass media1 that false information has been conveyed or that HIV/AIDS poses no risk to heterosexuals outside Africa. Generalised epidemics have occurred in Haiti and Papua New Guinea, and heterosexual transmission drives the epidemic in sex workers, their partners, clients, and their clients' partners in Asia and elsewhere. Such observations do not predict extensive or generalised spread, but neither do they indicate lack of any heterosexual transmission beyond the populations most at risk. As with hepatitis B virus infection, many heterosexual patients with HIV seem not to belong to any population that is most at risk, but still became infected.
Conveying the heterogeneity of risk is a challenge in public health in general. HIV/AIDS epidemiology changes slowly, current trends providing the basis for appropriate targeting of prevention and treatment eff orts. Just like other sexually transmitted infections, HIV/AIDS should be an integral component of sexual and reproductive health interventions and education, but targeting eff orts aimed at the risk populations and settings where HIV transmission is most intense is crucial. Accurate size estimation and mapping of populations most at risk in concentrated HIV/AIDS epidemics can be diffi cult, with underestimation as well as overestimation possible. More investment in surveillance and epidemiology is required for the continued and objective documentation of trends. Of ongoing concern is the long-term sustainability of eff orts in terms of the future burden of HIV and availability of the necessary funding. In addition to the debate around epidemiology, arguments are being made that too muchfunding is going to HIV/AIDS compared with other health priorities.10 Recent data show how far we are from universal access, and the problem is not excessive funding for HIV/AIDS, but continued inadequate funding for all major challenges in global health, and the need for their accurate measurement. In 2008, protection against major infectious diseases, such as malaria, tuberculosis, and HIV/AIDS, should be seen as a universal obligation, and universal access refers to everybody in need, everywhere.
Kevin M De Cock - Department of HIV/AIDS, WHO, Geneva 1211, Switzerland
Paul De Lay - Department of Evidence, Monitoring, & Policy, UNAIDS, Geneva, Switzerland
Recent debates about trends in HIV infections have overshadowed genuine achievements in addressing the pandemic.1 WHO, UNAIDS, and UNICEF have recently issued a series of reports that assess progress towards universal access to HIV prevention, treatment, and care.2,3 Leaders of the G8 countries had committed to this ambitious goal in Gleneagles, UK, in 2005 and in the political declaration made at the UN General Assembly.4,5 On the basis of data from 143 countries, by the end of 2007, almost 3 million people in low-income and middle-income countries were being maintained on antiretroviral therapy—1 million more than the previous year. Almost three-quarters of the individuals on therapy lived in sub-Saharan Africa, where measurable reductions in AIDS mortality are occurring, and 200 000 were children. Treatment coverage globally was estimated at 31%; the total estimated need for therapy under current treatment recommendations6 is 9·7 million people.
Coverage for antiretrovirals in HIV-positive pregnant women for prevention of mother-to-child transmission in low-income and middle-income countries increased from 9% in 2004 to 34% in 2007. In such countries, the percentage of young people having sex before age 15 years is decreasing in all regions, a continuation of trends detected earlier this decade.
Despite these gains, huge gaps in access remain. Only 20% of people with HIV in low-income and middleincome countries are aware of their infection status. Surveys indicate that 40% of men and 38% of women at ages 15–24 years had accurate and comprehensive knowledge about HIV and about how to avoid transmission. In countries with epidemics that are concentrated within the populations most at risk, HIV prevention programmes fail to reach many people at risk of acquiring HIV, including most men who have sex with men and injecting drug users.
Focusing scale-up of services where they are needed requires "knowing your epidemic", globally and locally.7 According to the 2007 UNAIDS/WHO AIDS epidemic update,8 at the end of 2007, 33·2 million people(range 30·6–36·1) were living with HIV. Some 2·5 million people became newly infected that year, and 2·1 million died of AIDS. AIDS remains the leading cause of death in Africa. These latest estimates refl ect expanded sets of data, including the use of population-based surveys, and improved methods of analysis, and are better than nearly all other estimates for other global health problems.
Sub-Saharan Africa, with two-thirds of those living with HIV, has seen self-sustaining HIV epidemics with very high levels of HIV prevalence in the general population of many countries. In most of the rest of the world, HIV has occurred in concentrated epidemics that aff ect specifi c groups at risk (men who have sex with men, injecting drug users, female commercial sex workers) and their partners. The recent Report of the Commission on AIDS in Asia9 supports the concept of predominantly concentrated epidemics in that populous region.
Compartmentalising the world into concentrated and generalised epidemics usefully conveys likely trends, yet incompletely captures the complexity and heterogeneity of the epidemic. The probability of heterosexual HIV spread is infl uenced by local HIV prevalence, sexual networks, rates of partner change, and types of partner selected. Risk of heterosexual acquisition of HIV varies enor mously internationally, though even very low risk is not zero risk.
It is this complexity around the likelihood and extent of heterosexual HIV transmission that is at the root of extreme claims in the mass media1 that false information has been conveyed or that HIV/AIDS poses no risk to heterosexuals outside Africa. Generalised epidemics have occurred in Haiti and Papua New Guinea, and heterosexual transmission drives the epidemic in sex workers, their partners, clients, and their clients' partners in Asia and elsewhere. Such observations do not predict extensive or generalised spread, but neither do they indicate lack of any heterosexual transmission beyond the populations most at risk. As with hepatitis B virus infection, many heterosexual patients with HIV seem not to belong to any population that is most at risk, but still became infected.
Conveying the heterogeneity of risk is a challenge in public health in general. HIV/AIDS epidemiology changes slowly, current trends providing the basis for appropriate targeting of prevention and treatment eff orts. Just like other sexually transmitted infections, HIV/AIDS should be an integral component of sexual and reproductive health interventions and education, but targeting eff orts aimed at the risk populations and settings where HIV transmission is most intense is crucial. Accurate size estimation and mapping of populations most at risk in concentrated HIV/AIDS epidemics can be diffi cult, with underestimation as well as overestimation possible. More investment in surveillance and epidemiology is required for the continued and objective documentation of trends. Of ongoing concern is the long-term sustainability of eff orts in terms of the future burden of HIV and availability of the necessary funding. In addition to the debate around epidemiology, arguments are being made that too muchfunding is going to HIV/AIDS compared with other health priorities.10 Recent data show how far we are from universal access, and the problem is not excessive funding for HIV/AIDS, but continued inadequate funding for all major challenges in global health, and the need for their accurate measurement. In 2008, protection against major infectious diseases, such as malaria, tuberculosis, and HIV/AIDS, should be seen as a universal obligation, and universal access refers to everybody in need, everywhere.
