[Mb-civic] How AIDS in Africa Was Overstated - Washington Post

[William Swiggard]

How AIDS in Africa Was Overstated
Reliance on Data From Urban Prenatal Clinics Skewed Early Projections

By Craig Timberg
Washington Post Foreign Service
Thursday, April 6, 2006; A01

KIGALI, Rwanda -- Researchers said nearly two decades ago that this tiny 
country was part of an AIDS Belt stretching across the midsection of 
Africa, a place so infected with a new, incurable disease that, in the 
hardest-hit places, one in three working-age adults were already doomed 
to die of it.

But AIDS deaths on the predicted scale never arrived here, government 
health officials say. A new national study illustrates why: The rate of 
HIV infection among Rwandans ages 15 to 49 is 3 percent, according to 
the study, enough to qualify as a major health problem but not nearly 
the national catastrophe once predicted.

The new data suggest the rate never reached the 30 percent estimated by 
some early researchers, nor the nearly 13 percent given by the United 
Nations in 1998.

The study and similar ones in 15 other countries have shed new light on 
the disease across Africa. Relying on the latest measurement tools, they 
portray an epidemic that is more female and more urban than previously 
believed, one that has begun to ebb in much of East Africa and has 
failed to take off as predicted in most of West Africa.

Yet the disease is devastating southern Africa, according to the data. 
It is in that region alone -- in countries including South Africa, 
Botswana, Swaziland and Zimbabwe -- that an AIDS Belt exists, the 
researchers say.

"What we know now more than ever is southern Africa is the absolute 
epicenter," said David Wilson, a senior AIDS analyst for the World Bank, 
speaking from Washington.

In the West African country of Ghana, for example, the overall infection 
rate for people ages 15 to 49 is 2.2 percent. But in Botswana, the 
national infection rate among the same age group is 34.9 percent. And in 
the city of Francistown, 45 percent of men and 69 percent of women ages 
30 to 34 are infected with HIV, the virus that causes AIDS.

Most of the studies were conducted by ORC Macro, a research corporation 
based in Calverton, Md., and were funded by the U.S. Agency for 
International Development, other international donors and various 
national governments in the countries where the studies took place.

Taken together, they raise questions about monitoring by the U.N. AIDS 
agency, which for years overestimated the extent of HIV/AIDS in East and 
West Africa and, by a smaller margin, in southern Africa, according to 
independent researchers and U.N. officials.

"What we had before, we cannot trust it," said Agnes Binagwaho, a senior 
Rwandan health official.

Years of HIV overestimates, researchers say, flowed from the long-held 
assumption that the extent of infection among pregnant women who 
attended prenatal clinics provided a rough proxy for the rate among all 
working-age adults in a country. Working age was usually defined as 15 
to 49. These rates also were among the only nationwide data available 
for many years, especially in Africa, where health tracking was 
generally rudimentary.

The new studies show, however, that these earlier estimates were skewed 
in favor of young, sexually active women in the urban areas that had 
prenatal clinics. Researchers now know that the HIV rate among these 
women tends to be higher than among the general population.

The new studies rely on random testing conducted across entire 
countries, rather than just among pregnant women, and they generally 
require two forms of blood testing to guard against the numerous false 
positive results that inflated early estimates of the disease. These 
studies also are far more effective at measuring the often dramatic 
variations in infection rates between rural and urban people and between 
men and women.

UNAIDS, the agency headed since its creation in 1995 by Peter Piot, a 
Belgian physician, produced its first global snapshot of the disease in 
1998. Each year since, the United Nations has issued increasingly dire 
assessments: UNAIDS estimated that 36 million people around the world 
were infected in 2000, including 25 million in Africa. In 2002, the 
numbers were 42 million globally, with 29 million in Africa.

But by 2002, disparities were already emerging. A national study in the 
southern African country of Zambia, for example, found a rate of 15.6 
percent, significantly lower than the U.N. rate of 21.5 percent. In 
Burundi, which borders Rwanda in central East Africa, a national study 
found a rate of 5.4 percent, not the 8.3 percent estimated by UNAIDS.

In West Africa, Sierra Leone, just then emerging from a devastating 
civil war, was found to have a national prevalence rate of less than 1 
percent -- compared with an estimated U.N. rate of 7 percent.

Such disparities, independent researchers say, skewed years of policy 
judgments and decisions on where to spend precious health-care dollars.

"From a research point of view, they've done a pathetic job," said Paul 
Bennell, a British economist whose studies of the impact of AIDS on 
African school systems have shown mortality far below what UNAIDS had 
predicted. "They were not predisposed, let's put it that way, to weigh 
the counterevidence. They were looking to generate big bucks."

The United Nations started to revise its estimates in light of the new 
studies in its 2004 report, reducing the number of infections in Africa 
by 4.4 million, back to the total four years earlier of 25 million. It 
also gradually decreased the overall infection rate for working-age 
adults in sub-Saharan Africa, from 9 percent in a 2002 report to 7.2 
percent in its latest report, released in November.

Peter Ghys, an epidemiologist who has worked for UNAIDS since 1999, 
acknowledged in an interview from his office in Geneva that HIV 
projections several years ago were too high because they relied on data 
from prenatal clinics.

But Ghys said the agency made the best estimates possible with the 
information available. As better data emerged, such as the new wave of 
national population studies, it has made revisions where necessary, he said.

"What has happened is we have come to realize that indeed we have 
overestimated the epidemic a bit," he said.

On its Web site, UNAIDS describes itself as "the chief advocate for 
worldwide action against AIDS." And many researchers say the United 
Nations' reliance on rigorous science waned after it created the 
separate AIDS agency in 1995 -- the first time the world body had taken 
this approach to tackle a single disease.

In the place of previous estimates provided by the World Health 
Organization, outside researchers say, the AIDS agency produced reports 
that increasingly were subject to political calculations, with the 
emphasis on raising awareness and money.

"It's pure advocacy, really," said Jim Chin, a former U.N. official who 
made some of the first global HIV prevalence estimates while working for 
WHO in the late 1980s and early 1990s. "Once you get a high number, it's 
really hard once the data comes in to say, 'Whoops! It's not 100,000. 
It's 60,000.' "

Chin, speaking from Stockton, Calif., added, "They keep cranking out 
numbers that, when I look at them, you can't defend them."

Ghys said he never sensed pressure to inflate HIV estimates. "I can't 
imagine why UNAIDS or WHO would want to do that," he said. "If we did 
that, it would just affect our credibility."

Ghys added that studies now show that the overall percentage of Africans 
with HIV has stabilized, though U.N. models still show increasing 
numbers of people with the virus because of burgeoning populations.

Many other researchers, including Wilson from the World Bank and two 
epidemiologists from the U.S. Agency for International Development who 
wrote a study published last week in the Lancet, a British medical 
journal, dispute that conclusion, saying that the number of new cases in 
Africa peaked several years ago.

Some involved in the fight against AIDS say that tallying HIV cases is 
not nearly as important as finding the resources to fight the disease. 
That is especially true now that antiretroviral drugs are more 
affordable, making it possible to extend millions of lives if enough 
money and health-care workers are available to facilitate treatment.

"It doesn't matter how long the line is if you never get to the end of 
it," said Francois Venter, a South African doctor and head of 
Johannesburg General Hospital's rapidly expanding antiretroviral drug 
program, speaking in an interview in Johannesburg.

But to the researchers who drive AIDS policy, differences in infection 
rates are not merely academic. They scour the world looking for evidence 
of interventions that have worked, such as the rigorous enforcement of 
condom use at brothels in Thailand and aggressive public campaigns that 
have urged Ugandans to limit their sexual partners to one.

Programs deemed successful are urged on other countries and funded 
lavishly by international donors, often to the exclusion of other programs.

Rwanda, a mountainous country of about 8.5 million people jammed into a 
land area smaller than Maryland, has relied on approaches similar to 
those used in Uganda, and may have produced similar declines in HIV. 
UNAIDS estimated in 1998 that 370,000 Rwandans were infected, equal to 
12.75 percent of all working-age adults and a substantial percentage of 
children as well. Every two years since, the agency has lowered that 
estimate -- to 11.2 percent in 2000, 8.9 percent in 2002 and 5.1 percent 
in 2004.

Dirk van Hove, the top UNAIDS official in Rwanda, said the next official 
estimate, due in May, would show an infection rate of "about 3 percent," 
in line with the new national study. He said the U.N. estimate tracked 
the declining prevalence.

Rwandan health officials say their national HIV infection rate might 
once have topped 3 percent and then declined. But it's just as likely, 
they say, that these apparent trends reflected nothing more than flawed 
studies.

Even so, Rwanda's cities show signs of a serious AIDS problem not yet 
tamed. The new study found that 8.6 percent of urban, working-age women 
have HIV. Overall, officials say, 150,000 Rwandans are infected, less 
than half the number estimated by UNAIDS in 1998.

Bruno Ngirabatware, a physician who has treated AIDS patients in Kigali 
since the 1980s, said he has seen no evidence of a recent decline in HIV 
infection rates.

"There's lots of patients there, always," he said.

http://www.washingtonpost.com/wp-dyn/content/article/2006/04/05/AR2006040502517.html?nav=hcmodule
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