For the first time since the AIDS pandemic was identified a quarter-century ago, “we are seeing a decline in global AIDS deaths,” reports Dr. Kevin De Cock, director of AIDS at the World Health Organization (WHO). Revised figures released by WHO and the Joint UN Programme on HIV/AIDS (UNAIDS) also show that new infections from HIV, the virus that causes the disease, have begun to fall as well.
Citing more accurate data-collection methods, the AIDS Epidemic Update 2007, released jointly by UNAIDS and WHO in November, estimates that there are about 33.2 million people worldwide living with HIV, compared with the figure of 39.5 million the two institutions had released the year before. The change in the number of people living with HIV was not an actual decline, the Update hastened to add, but a statistical revision of estimates after detailed national surveys in about 30 countries demonstrated that earlier totals were too high.
The revision generated considerable controversy, with some independent AIDS experts arguing that the data should have been adjusted earlier. But all agree that the newer, more accurate figures have brought into the open an important shift in the epidemic’s progression, one that was not apparent with the older statistics.
In adjusting their overall estimates retroactively, to previous years, the two UN institutions revealed some positive trends over time. First, new infections with HIV were likely to have peaked in the late 1990s, when more than 3 million people became newly infected annually. The revised estimates indicate that this total has actually been declining since then, to some 2.5 million newly infected in 2007. Second, the number of annual deaths from AIDS has also started to fall, from a high point of around 2.4 million in 2005 to about 2.1 million in 2007.
To an extent, these changing trends reflect some of the first significant successes in AIDS-prevention efforts. In a number of countries, according to national survey results, young people are engaging in less risky sexual behaviour, whether by using protective condoms or by having fewer or no partners. The report cites evidence of such behavioural changes in Botswana, Cameroon, Kenya, Malawi, Togo, Zambia, Zimbabwe and a few other countries.
Neither the shift in the disease’s overall trend nor the revision in the estimates has changed one glaring fact: sub-Saharan Africa remains the epicentre of the global malady. Of all those living with HIV, about 22.5 million, or 68 per cent of the world’s total, are in sub-Saharan Africa. The region accounts for the same percentage of people newly infected with the virus, as well as 76 per cent of those who die of AIDS annually.
In contrast to other world regions, women and children are far more vulnerable to the disease in sub-Saharan Africa. Of those Africans living with HIV, 61 per cent are women, while fully 90 per cent of all HIV-positive children in the world are in sub-Saharan Africa.
Within the continent, Southern Africa is by far the most afflicted, accounting for around a third of all new HIV infections globally and about a third of people living with HIV. In eight countries — Botswana, Lesotho, Mozambique, Namibia, South Africa, Swaziland, Zambia and Zimbabwe — national adult HIV-prevalence rates exceed 15 per cent. Southern African countries, says Daniel Halperin, an AIDS expert at the US’s Harvard School of Public Health, are continuing to experience “real nightmares.”
In poor, largely rural countries with weak health systems and limited ability to collect data, measuring the extent of an infectious disease is always difficult, notes Dr. Paul De Lay, a UNAIDS director.
Early estimates of HIV/AIDS were based mainly on information collected on young women visiting public health clinics either because they were pregnant or because they feared they had been infected. Those results were then extrapolated to the rest of the population to come up with estimated national infection rates. But over time experts realized that data from urban clinics were skewed: they gave too much statistical weight to sex workers, drug users and people with multiple partners, relative to other sectors of the population.
As donor countries gradually began providing more funds to combat the disease, some of those resources were allocated for more scientifically designed national surveys. Across the board, the surveys showed that the scale of the epidemic was somewhat less than previously thought.
Whether the numbers are going up or down, there should be no complacency, UNAIDS and other experts warn. In a number of countries that had previously made progress in reducing infection rates, but in which anti-AIDS programmes have diminished, “we are seeing a return of the epidemic,” he notes. The Update reports that prevalence rates are rising again in the US, the UK and Germany — as well as in Uganda, which once was hailed for its success in bringing down HIV rates.
Nor should the international community slacken its own efforts, argue AIDS advocates. Current international spending, at around $10 bn annually, continues to fall short of actual needs. “There’s still a huge epidemic out there that still needs huge resources to win the battle,” says Paul Zeitz, executive director of the Global AIDS Alliance, an international non-governmental group headquartered in Washington, DC.
“We have to recognize the very long-term nature of the HIV pandemic,” says Dr. De Cock. “We’re facing decades of this problem.” Of those currently infected, “some of them require treatment now, and all of them will in time. The qualitative implications have changed very little.”