By David Brown
Washington Post Staff Writer
Wednesday, November 22, 2006
Seven African countries are experiencing a decline in the prevalence of HIV infection among young, urban adults, finally reaping the benefit of AIDS prevention and treatment, the United Nations said yesterday in its annual report on the global epidemic.
That good news was offset by troubling signs that the first African country to reverse the epidemic, Uganda, is experiencing a resurgence of infection, as is Thailand, another early success story.
Based on hundreds of national and regional surveys, the report stitches a patchwork of progress and setbacks: a successful national treatment program in Brazil and a new, aggressive response by the Chinese government, alongside a worsening HIV epidemic in the former Soviet bloc and a new outbreak among gay men in Europe.
But the pendulum swing underway in Uganda and Thailand appears to mark a new phase in the 25-year-old AIDS epidemic.
"It should not be a surprise that the countries first to show success will be the first to have a rebound and show problems," said Peter Piot, director of UNAIDS, the program run by the United Nations and the World Bank. "It is something that I am really very worried about."
He and other epidemiologists are trying to learn whether the resurgence of infection in the two nations is a demographic copy of the first wave of AIDS cases or represents the spread of infection to new groups. They are also trying to understand how big a part "prevention fatigue" may be playing in the trend.
"We really don't have an idea why it is happening," Piot said.
The findings make clear that vulnerable populations may differ somewhat from country to country, and that entire nations may be at different stages in the epidemic.
"One of the main messages is the need of countries to know their epidemic," said Paul De Lay, director of monitoring and evaluation at UNAIDS. "The epidemics are continuing to evolve."
Worldwide, 39.5 million people are infected by HIV, up 2.6 million from two years ago. This year, an estimated 4.3 million people will become infected and 2.9 million will die, according to the report. Two-thirds of all adults and children with HIV live in sub-Saharan Africa.
In many countries, HIV incidence is uncertain. Estimates based on the infection rate of pregnant women at public clinics are unrealistically high, and estimates based on household surveys (which often miss such high-risk people as commercial sex workers, drug users, soldiers and migrants) are deceptively low.
Most estimates now combine the methods, and although they are generally lower than previously cited rates, they are still shockingly high for many countries. In Zimbabwe, for example, 20 percent of people 15 to 49 are thought to be infected with the AIDS virus.
Prevalence of the disease in city dwellers 15 to 24, who make up a key demographic gauge of the epidemic's trajectory, has fallen by at least 25 percent in Zimbabwe, Malawi, Kenya, Botswana, Burundi, Rwanda and Ivory Coast. In Zimbabwe, Kenya, Botswana and Tanzania, the rate fell a similar amount among rural people.
In Uganda, the national prevalence is 6.7 percent -- a steep decline from a decade ago, attributed to fewer sex partners, later "sexual debut" by teenagers, increased condom use and rising AIDS mortality through the 1990s. Now, however, AIDS prevalence is rising in some populations, such as rural men (up from 5.6 to 6.5 percent) and rural women (6.9 percent to 8.8 percent), according to recent surveys.
Piot said Uganda also suffered from a period of "decreased credibility" of condoms, the consequence of messages by some fundamentalist groups, a run of defective condoms and then a shortage of condoms.
In Thailand, HIV infection used to be seen almost exclusively in prostitutes and their male clients. The spread of the virus was nearly halted by a national campaign for "100 percent condom use" in commercial sex transactions. Now, however, the epidemic is spreading to married women, who accounted for one-third of new infections last year. It is also becoming far more prevalent in male homosexuals -- up from 17 percent in Bangkok in 2003 to 28 percent in 2005.
In Western Europe, just over one-third of the new HIV infections last year occurred in "men who have sex with men," the term preferred by epidemiologists, because many men infected that way do not consider themselves to be homosexual. The Netherlands, Britain, Portugal, Switzerland and Belgium reported steep increases in the number of infections in that population since 2000.
About 55 percent of new infections in Europe were acquired through opposite-sex intercourse, with three-quarters occurring in immigrants or migrants. The report noted the need to target prevention programs to them.
A major sign of progress is that since 2002, 2 million years of life have been gained by the use of antiviral drugs in low- and middle-income countries. In Africa, 790,000 years of life have been gained, most in the past two years.
Lifesaving combinations of antivirals became widely used in rich countries beginning in 1996. The idea that a decade later they might be used by more than a handful of people in poor countries was viewed by most as unrealistic and possibly dangerous.
Piot said the report demonstrates that policymakers such as himself "need to safeguard early successes like Uganda." He added: "You develop complacency, and the attention moves to something else. That is completely human. The job is never finished, particularly when you have had some successes."