全球艾滋病患者估计数量下调

Global estimates of the AIDS epidemic this year were revised to 33.2 million, down 6.3 million from 39.5 million projected last year, due to improved data gathering, according to AIDS experts at the United Nations and World Health Organization.

An estimated 2.5 million people became newly infected this year, and 2.1 million died of the blood-borne virus, spread through sex, drug use and mother-to-child transmission, the agencies said.

The 16% cut -- largely the result of statistical adjustment rather than improvements in world health -- was good tidings for a field battered by bad news from the recent failure of a major vaccine trial.

In Geneva, Paul DeLay, director of evidence, monitoring and policy for the U.N. Joint Programme on HIV/AIDS, said a big part of the reduction in AIDS' global toll came from the previously reported cut in India's caseload, and the balance from reduced estimates in five countries in sub-Saharan Africa: Angola, Kenya, Mozambique, Nigeria, and Zimbabwe.

Asked how estimates could have been so far off, Dr. DeLay said, 'The data are tough to get.'

'Measurement of infectious diseases has always been a challenge in the global setting of low-income developing countries,' Dr. DeLay said. 'The challenge is equally true for TB, polio and childhood diarrhea. In spite of this year's revision, the numbers for HIV are some of the best we've got.'

In the early days of the epidemic, estimates of AIDS infection came largely from tests of pregnant women conducted at prenatal clinics. The latest revision comes from the addition of improved national population estimates in 30 countries with widespread AIDS. These countries undertook neighborhood surveys involving family interviews and blood tests.

Dr. DeLay cautioned countries to maintain vigilance against a resurgent pandemic. 'If you let your guard down -- and we've seen this in the States, Thailand and Uganda -- with the next generation moving to sexual maturity, you start all over again,' Dr. DeLay said. He said U.S. disease-control experts are expected shortly to raise their estimates of AIDS infections above the 40,000-a-year rate of recent years.

联合国及世界卫生组织(WHO)的艾滋病专家表示，因数据采集过程获得改进，今年的全球艾滋病患者估计数量被调整为3,320万名，较去年预测的3,950万名减少630万。

联合国及世界卫生组织称，估计今年会新增250万名爱滋病患者，210万人因艾滋病致死。艾滋病病毒通过血液传播，主要传播途径包括性传播、共用注射工具和母婴传播。

今年的估计数量降低了16%，虽然这主要是缘于统计过程的调整，而非世界人口健康状况的改善，但仍不失为好消息。最近一项主要艾滋病疫苗的试验失败，使抗艾滋病事业遭受重创。

联合国艾滋病规划署(U.N. Joint Programme on HIV/AIDS)监测和评价司司长保罗•戴雷尔(Paul DeLay)在日内瓦表示，全球艾滋病患者减少主要应归因于印度艾滋病患者的报告数量此前作了下调，以及安哥拉、肯尼亚、莫桑比克、尼日利亚和津巴布韦这五个撒哈拉以南非洲国家艾滋病患者的估计数量有所下调。

当被问及为什么估计数量会有如此大的偏差时，戴雷尔表示，数据采集难度很大。

他说，在低收入发展中国家，传染病患者的统计一直是个挑战，对肺结核、小儿麻痹症和儿童腹泻同样如此。尽管艾滋病患者估计数今年作了修正，但这一数据仍属于最精确的统计数据。

在艾滋病当年刚开始蔓延时，艾滋病患者的估计数量主要得自于对孕妇的产前检查。这次的修正主要得益于世界30个艾滋病蔓延国家全国人口统计过程的改善。这些国家采取了挨家挨户的调查，包括入户访问和血液检查。

戴雷尔告诫各国应保持警惕，以防艾滋病的蔓延势头再度转强。他说，就象美国、泰国和乌干达曾经历过的一样，如果你放松了警惕，随着下一代进入性成熟期，你就必须一切从头开始。他说，美国的疾病控制专家预计很快将对该国近年来每年新增艾滋病患者4万名这一估计值进行上调。