An age- and sex-structured HIV epidemiological model: features and applications.

An important challenge in modelling the human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) epidemic is to use the increasing quantity of disease surveillance data to validate estimates and forecasts. Presented is a novel model for forecasting HIV incidence by age and sex and among sentinel groups for which data are available. This approach permits a closer relationship between forecasting and surveillance activities, and more accurate estimates validated to data. As inputs the model uses an estimate of the HIV prevalence, country demographic data, and a profile of the sexual risk of HIV infection by age, to project HIV incidence, prevalence, number of AIDS cases and population. The following examples of the use of the model are given: forecasting HIV incidence in East Africa, by age, sex, and among pregnant women; 3-5-year forecasts of HIV incidence; modelling mixed risk behaviour HIV epidemics in South-east Asia; demographic indicators; and targeting a preventive vaccine by age group.     

博茨瓦纳的艾滋病防治经验

一个人口170万,孕产妇HIV感染率高达37.4%的非洲国家,艾滋病使全国人均期望寿命由67岁下降到现在的近40岁,全国有30万人感染了HIV,有11万人需要艾滋病抗病毒治疗,有4万名艾滋病孤儿。政府将控制艾滋病视为社会生存和发展问题,通过多部门合作、综合干预及有效的国际合作,使艾滋病得到了初步有效的控制。     

HIV and AIDS: where is the epidemic going?

Routine surveillance of HIV (human immunodeficiency virus) infection and AIDS has been established over the past decade in many countries around the world. HIV estimates derived from empirical data are essential to the assessment of the HIV situation in different parts of the world and trends are used in tracking the development of regional epidemics, thereby keeping intervention activities focused on realities. As of the end of 1995, and following an extensive country-by-country review of HIV/AIDS data, a cumulative total of 6 million AIDS cases were estimated to have occurred in adults and children worldwide and currently 20.1 million adults are estimated to be alive and infected with HIV or have AIDS. Of the total prevalent HIV infections, the majority remain concentrated in eastern, central and southern Africa, but the epidemic is evolving with spread of infection from urban to rural areas, as well as to West and South Africa, India and South-east Asia, and to a lesser extent--with proportional shifts to heterosexual infections--in North America, western Europe and Latin America. While the longer-term dimensions of the HIV epidemic at global level cannot be forecast with confidence, WHO currently projects a cumulative total of close to 40 million HIV infections in men, women and children by the year 2000. By that time, the male:female ratio of new infections will be close to 1:1. Recent trends indicate that HIV prevalence levels may be stabilizing or even decreasing among pregnant women in southern Zaire and parts of Uganda, among military recruits aged 21 in Thailand, and in some populations of northern Europe and the USA. While these changes may take place as part of the intrinsic dynamic of the epidemic, there is some evidence that declines in HIV prevalence are related to declines in HIV incidence which are, at least partly, due to prevention efforts. The challenge of surveillance and evaluation methods is now to identify the ingredients of success which may reveal a glimmer of hope.     

Second-generation HIV surveillance: better data for decision-making

This paper seeks to outline the key elements of the expanded surveillance efforts recommended by the second-generation HIV surveillance approach. Second-generation systems focus on improving and expanding existing surveillance methods and combine them in ways that have the greatest explanatory power. The main elements of this approach include: considering biological surveillance - HIV, AIDS, sexually transmitted infections (STIs) - and behavioural surveillance as integral components, targeting surveillance efforts at segments of the population where most new infections are concentrated - which might differ depending on the stage and type of the epidemic - and providing the rationale for the optimal use of data generated for monitoring the HIV epidemic and evaluating national AIDS control programmes. The paper emphasizes improvements in existing surveillance methodologies and discusses in detail crucial issues such as the validity of HIV prevalence data measured in pregnant women and linking HIV surveillance and behavioural data collection. In addition, a strategic partnership between second-generation surveillance and AIDS programme evaluation is proposed that stresses the complementary roles of these data collection activities in determining the effectiveness of prevention and care programmes and explaining the epidemiological trend data collected by sentinel serosurveillance systems. In conclusion, second-generation HIV surveillance systems provide a comprehensive, cost-effective and appropriate response to the information needs of AIDS control programmes. The implementation of such systems, including a better use of the data generated by the system, will ensure that national programmes are in the best possible position to respond to the challenges of the epidemic.     

云南省1989～1998年艾滋病流行与控制的研究

目的　研究云南省艾滋病病毒（ＨＩＶ） 感染流行十年来的特征和趋势,讨论云南省对ＨＩＶ 的流行与控制。方法　用哨点监测的方法纵向观察和比较各类人群流行率,估算ＨＩＶ 感染者总数和流行率。结果　云南省１９８９ ～１９９８ 年累计报告ＨＩＶ 感染者５ ８６８ 例,ＡＩＤＳ２２９ 例;累计流行县达１０３ 个,其中高流行县１５ 个,中度流行县８ 个。ＨＩＶ 流行由农村向城市蔓延、由边境向内地蔓延。ＨＩＶ 感染者在职业构成上农民的比例逐年下降,城市无业者所占比例至１９９８ 年已达５０．２ ％ ;在ＨＩＶ 感染者中男性／ 女性的比例到１９９８ 年为３∶１ ;在暴露因素中１９９８ 年因吸毒感染的占７３ ％ ,性传播占１３ ．６ ％ ;ＨＩＶ 流行率逐年上升,１９９８ 年静脉吸毒哨点ＨＩＶ 流行率全省平均为２４．４ ％ 、暗娼为２ ．４％ 、性病哨点为１ ．６％ 、孕产妇哨点为０ ．２ ％ 。全省至１９９８ 年累计ＨＩＶ 感染人数估计为３７ ７３７ 人,１５ ～４９ 岁成人ＨＩＶ 流行率为０．１５ ％ 。结论　云南省ＨＩＶ 流行在继续发展,加强对该病的防制力度迫在眉睫     

中国1995-2009年艾滋病哨点监测主要人群艾滋病病毒感染流行趋势分析

目的 分析中国吸毒者、暗娼、性病门诊就诊者、男男性行为者、孕产妇5类人群的艾滋病病毒(HIV)感染流行趋势,为艾滋病综合防治和科学干预提供信息和依据.方法 1995-2009年,在哨点监测期内以重复横断面调查的方法对吸毒者、暗娼、性病门诊就诊者、男男性行为者、孕产妇5类人群进行监测(采血及问卷调查).结果 吸毒人群HIV抗体阳性检出率(中位数)在疫情较重省份从1996年开始呈快速上升,1999-2000年达到高点(19.2%),2001-2003年逐步下降,2004年后趋于平稳状态;在疫情居中省份从2001年开始呈小幅上升,2004年达到相对高点(2.9%)后趋于平稳,近两年又呈小幅下降趋势;在疫情较轻省份一直处于低水平.暗娼人群HIV抗体阳性检出率(中位数)在疫情较重省份从1999年开始小幅上升并达到高点(1.5%),之后下降并维持在较低水平;在疫情居中省份和较轻省份一直处于低水平.性病门诊就诊人群HIV抗体阳性检出率(中位数)一直维持在较低水平,低于0.7%.男男性行为人群HIV抗体阳性检出率近两年均大于1%,部分哨点大于10%,且呈快速上升趋势,成为近年来推动艾滋病疫情发展的重要原因之一.孕产妇人群HIV抗体阳性检出率(中位数)在疫情较重省份从1997年开始呈缓慢上升,之后趋于平稳状态(0.3%);在疫情居中省份和较轻省份一直处于低水平.结论 男男性行为人群HIV抗体阳性检出率呈上升趋势;吸毒者、暗娼、性病门诊就诊者、孕产妇人群的HIV抗体阳性检出率都趋于相对平稳状态.吸毒人群疫情仍集中在疫情较重的6个省份.暗娼和性病门诊就诊人群疫情总体仍处于较低水平,但流行范围在不断扩大.

Abstract：

Objective To effectively monitor the time trend of HIV prevalence and epidemic among injecting drug users ( IDUs ), female sex workers (FSWs), sexually transmitted disease (STD)clinic attendants, men who have sex with men (MSM) and pregnant women etc., to provide information for evaluation on strategies regarding comprehensive HIV prevention and effectiveness of intervention, in China. Methods Cross-sectional studies had been repeatedly conducted on sentinel surveillance program with uniformed questionnaire and collection of venous blood specimen among IDUs, FSWs, STD clinic attendants, MSM and pregnant women, from 1995 to 2009. Results HIV prevalence (median) among IDUs had been increasing rapidly since 1996, reaching the plateau (19.2%) in 1999-2000, then gradually decreasing in 2001-2003, and leveling off since 2004 in those relatively hard-hit epidemic provinces. HIV prevalence among drug users had increased a bit since 2001, achieving high level (2.9%) in 2004 before leveling off, showing a slight downward trend in the past two years among the medially-hit epidemic provinces, while it maintained at a low level in those low epidemic provinces. HIV prevalence (median) among FSWs had been slightly increasing,reaching a high level ( 1.5% ) in 1999, then decreased and maintained at a low level in relatively hard-hit provinces. HIV prevalence among FSWs maintained at a low level in medially-hit and low epidemic provinces. HIV prevalence(median) among STD clinic attendants had been maintained at a lower level, lower than 0.7%. HIV prevalence among MSM had been consistently greater than 1%, and was increasing year by year, becoming one of the most important drivers of the HIV/AIDS epidemic over the past years. HIV prevalence (median) among pregnant women had slightly been increasing since 1997, then leveling off over the past years in those relatively hard-hit provinces (0.3%). HIV prevalence among pregnant women had maintained at a low level in the medial and low epidemic provinces. Conclusion Data from sentinel surveillance programs showed a leveling-off situation on HIV prevalence rates among IDUs, FSWs, sexually transmitted infections clinic patients and pregnant women. However, HIV prevalence among MSM had increased significantly since 2005, indicating the high speed of transmission among this population. Epidemic among IDUs had still been concentrated in those relatively hard-hit epidemic provinces. As for FSWs and STD patients, the overall epidemic remained at low level, but the areas of epidemic kept expanding.     

1996-2011年新乡市艾滋病流行病学分析

目的分析新乡市艾滋病流行现状,为制定本市艾滋病防治策略提供流行病学依据。方法对1996-2011年新乡市艾滋病专报数据库、哨点监测、专题调查等资料进行分析。结果 1996年新乡市报告首例艾滋病感染者,截至2011年底新乡市累计确认艾滋病病毒(HIV)感染者884例,其中艾滋病病人413例,死亡309例,感染途径以上世纪90年代参与既往有偿供血及受血者为主。结论新乡市艾滋病呈低流行状态,病例分布呈局灶性分布,传播途径逐步多样化,呈现由高危人群向一般人群扩散趋势。     

HIV epidemic -- a global update. Excerpts from the UN World AIDS Day report

According to the 1997 United Nations World AIDS Day Report, over 30 million adults and children worldwide are HIV-infected and, if current transmission rates remain constant, 40 million people will be infected by the year 2000. In 1997, an estimated 5.8 million people became HIV-infected and 2.3 million died of AIDS-related infections. Nearly half of these deaths were in women and 460,000 were in children under 15 years. In sub-Saharan Africa, where the epidemic is progressing most rapidly, 7.4% of the population aged 15-49 years is HIV-positive. Unprotected sex accounted for most of the 3.4 million new HIV infections among adults in sub-Saharan Africa in 1997. In Asia, the epidemic is more diverse, both in terms of intercountry variation and modes of transmission. In the developed world, newly available antiretroviral drugs are reducing the speed at which HIV-infected people develop AIDS. Of particular concern is the impact of HIV/AIDS on reversing gains in life expectancy and child survival in developing countries. Moreover, an estimated 9 out of 10 HIV-positive people worldwide are not aware they are infected. The future course of the epidemic depends in large part on expanded access to information about how HIV is transmitted and how to avoid infection.     

“四免一关怀”政策实施十年来中国艾滋病疫情变化及特征分析

目的 分析“四免一关怀”政策实施10年来中国艾滋病疫情变化及特征.方法 以全国艾滋病综合防治信息系统数据为基础,分析艾滋病病毒(human immunodeficiency virus,HIV)抗体检测、新发现HIV感染者和获得性免疫缺陷综合症(acquired immunodeficiency syndrome,AIDS)病例的特征,分析6类哨点监测人群HIV感染率变化.结果 2004-2013年的10年间,我国每年开展HIV抗体检测量从2004年的1 968万人次增加到2013年的11 100万人次,上升了5.6倍,每年新发现并报告的病例数从2004年的4.76万例增加到2013年的9.01万例,增加了1.9倍.艾滋病主要流行模式从以血液传播为主转变为以性接触传播为主.除男男性行为人群HIV感染率呈上升趋势外,暗娼、性病男性就诊者、长卡司机和孕产妇人群的HIV感染率均保持在1％以下的低水平,吸毒者HIV感染率从2005年的7.5％一直持续下降到2013年的3.6％,累计下降了52％.结论 “四免一关怀”政策实施10年我国基本控制了艾滋病疫情快速上升的势头.随着艾滋病流行模式的转变,艾滋病防治工作面临诸多新挑战,亟需在政策和策略上取得新的突破.     

Battling AIDS in America: an evaluation of the National HIV/AIDS Strategy

Thirty years ago, the Centers for Disease Control and Prevention reported the first cases of AIDS in the United States. Since then, more than half a million Americans have died of AIDS, and 1.1 million people are currently living with HIV in the United States. In an attempt to reinvigorate the domestic response to the HIV epidemic, the Obama administration developed and released the National HIV/AIDS Strategy for the United States (NHAS). The NHAS has 3 focus areas: reducing new infections, improving access to care and health outcomes, and reducing HIV-related disparities. With ambitious five-year targets set for each goal, the NHAS requires significant fiscal investment to achieve its desired impact on the domestic HIV epidemic.     

宜昌市孕产妇艾滋病知识调查及HIV、HCV和梅毒监测结果

目的:了解宜昌市孕产妇艾滋病知识知晓水平以及艾滋病病毒(HIV)、丙型肝炎病毒(HCV)利梅毒的感染状况,为阻断艾滋病母婴传播提供科学依据。方法:对宜昌市400名孕产妇进行问卷调查,采集血样进行HIV、HCV和梅毒的血清学检测。结果:400名调查对象的艾滋病知识总知晓率为92.75%,高危行为少,HCV和梅毒感染率各为0.50%,未发现HIV抗体阳性。结论:HIV、HCV和梅毒在宜昌市孕产妇人群呈低流行状态,今后应继续加强艾滋病知识的宣传教育,开展产前常规HIV和梅毒检测,阻断艾滋病母婴传播途径。     

Projections of HIV infections and AIDS cases to the year 2000

After the recognition of AIDS (acquired immunodeficiency syndrome) in the early 1980s, uncertainty about the present and future dimensions of HIV (human immunodeficiency virus) infection led to the development of many models to estimate current and future numbers of HIV infections and AIDS cases. The Global Programme on AIDS (GPA) of the World Health Organization (WHO) has developed an AIDS projection model which relies on available HIV seroprevalence data and on the annual rate of progression from HIV infection to AIDS for use in areas where reporting of AIDS cases is incomplete, and where scant data are available to quantify biological and human behavioural variables. Virtually all models, including the WHO model, have projected large increases in the number of AIDS cases by the early 1990s. Such short-term projections are considered relatively reliable since most of the new AIDS cases will develop in persons already infected with HIV. Longer-term prediction (10 years or longer) is less reliable because HIV prevalence and future trends are determined by many variables, most of which are still not well understood. WHO has now applied the Delphi method to project HIV prevalence from the year 1988 to mid-2000. This method attempts to improve the quality of the judgements and estimates for relatively uncertain issues by the systematic use of knowledgeable "experts". The mean value of the Delphi projections for HIV prevalence in the year 2000 is between 3 and 4 times the 1988 base estimate of 5.1 million; these projections have been used to obtain annual estimates of adult AIDS cases up to the year 2000. Coordinated HIV/AIDS prevention and control programmes are considered by the Delphi participants to be potentially capable of preventing almost half of the new HIV infections that would otherwise occur between 1988 and the year 2000. However, more than half of the approximately 5 million AIDS cases which are projected for the next decade will occur despite the most rigorous and effective HIV/AIDS prevention efforts since these AIDS cases will develop in persons whose HIV infection was acquired prior to 1989. The Delphi projections of HIV infection and AIDS cases derived from the WHO projection model need to be periodically reviewed and modified as additional data become available. These projections should be viewed as the first of many attempts to develop estimates for planning strategies to combat the HIV/AIDS pandemic in the 1990s.     

黑龙江省艾滋病疫情分析

目的:分析黑龙江省艾滋病的流行病学特点和流行趋势,为制定HIV/AIDS预防和控制策略提供科学依据。方法:收集和整理黑龙江省1993~2004年HIV/AIDS疫情监测资料和哨点资料,进行统计分析。结果:黑龙江省1993~2004年累计报告HIV/AIDS182例,其中AIDS病人44例,死亡22例。黑龙江省HIV感染已进入快速增长阶段,HIV感染类型已经由1999年以前不规范采供血途径为主转到目前以性传播途径为主,且女性感染者比例在增加,由1999年以前的19.6%上升到目前的33.8%。结论:黑龙江省正面临防制艾滋病的关键时期,采取有效的防制措施刻不容缓。     

中国1995-2009年吸毒者艾滋病毒感染和梅毒流行趋势分析

目的 了解中国不同地区吸毒者艾滋病和梅毒流行特点和变化趋势.方法 收集1995年以来中国艾滋病监测系统病例报告、哨点监测和疫情估计信息,分析吸毒者艾滋病病例报告数量与分布变化情况,吸毒者HIV和梅毒感染率变化趋势以及吸毒行为的变化情况.结果 中国吸毒者规模在过去6年中基本保持稳定,艾滋病病例报告中吸毒者所占比例逐年下降,从2005年之前的44.2%下降到2009年的25.8%.2009年哨点监测数据显示,中国吸毒者HIV和梅毒感染率差异较大,西南地区高东北地区低的态势较为明显.2009年吸毒者哨点HIV抗体平均检出率为6.2%,梅毒为3.7%;注射吸毒者HIV平均感染率为9.2%,梅毒为4.0%.多年监测结果显示,1995-1999年为全国吸毒人群HIV感染的快速增长期,2000年之后注射吸毒者流行进入平台期,最近3年HIV抗体检出率维持在9.0%～10.0%、梅毒检出率在3.5%～4.5%之间波动.结论 在未来一段时期内吸毒行为仍是中国艾滋病流行的重要影响因素;应根据区域流行特点有针对性地制定艾滋病防治措施.     

2008年柳州市艾滋病哨点监测结果分析

目的了解柳州市各类高危人群中艾滋病流行状况及相关行为信息。方法按照《广西HIV哨点监测实施方案》要求,分别对性病门诊就诊者、吸毒者、孕产妇、暗娼4类重点人群进行问卷调查和艾滋病病毒(HIV)抗体、梅毒抗体检测。结果 2008年共监测4类高危人群1396人,检出HIV抗体阳性24人,艾滋病检出率6.8%;检出梅毒抗体阳性15人,梅毒检出率1.6%。结论柳州市高危人群艾滋病检出率较高,疫情仍处于很高流行态势。     

2008年柳州市艾滋病哨点监测结果分析

目的了解柳州市各类高危人群中艾滋病流行状况及相关行为信息。方法按照《广西HIV哨点监测实施方案》要求,分别对性病门诊就诊者、吸毒者、孕产妇、暗娼4类重点人群进行问卷调查和艾滋病病毒(HIV)抗体、梅毒抗体检测。结果 2008年共监测4类高危人群1396人,检出HIV抗体阳性24人,艾滋病检出率6.8%;检出梅毒抗体阳性15人,梅毒检出率1.6%。结论柳州市高危人群艾滋病检出率较高,疫情仍处于很高流行态势。     

Computing back-calculation estimates of aids epidemic

The method of back-calculation estimates the number of HIV infections from AIDS incidence data and projects future AIDS incidence. We explore a conditional likelihood approach for computing estimates of the number of HIV infections and the parameters in the epidemic density. This method is asymptotically equivalent to the usual likelihood method. The asymptotic normal distribution of the estimates facilitates the computation of confidence intervals. We compute standard deviations for the estimates of HIV incidence and project AIDS incidence from the underlying multinomial distributions. We illustrate the methods with applications to AIDS data in the United States.     

安徽省示范区孕产妇艾滋病病毒抗体咨询与检测数据分析

目的探讨安徽省艾滋病综合防治示范区孕产妇艾滋病病毒抗体咨询与检测服务现状及存在问题。方法分析21个示范区2009～2011年全国预防艾滋病母婴传播信息系统网络直报孕产妇艾滋病病毒抗体咨询与检测报表数据。结果婚检人群的艾滋病病毒抗体检测率21.5%,阳性率8.0/10万;产期检查孕妇检测率为74.3%,阳性率21.3/10万;住院分娩产妇检测率78.5%,阳性率10.0/10万,其中孕期检查时检测率为28.7%,阳性率16.2/10万,仅临产时检测率49.8%,阳性率6.4/10万。结论预防艾滋病母婴传播项目工作深入开展,与妇幼保健常规工作相结合的工作要求到进一步落实。产妇的孕期检测信息可能存在遗漏现象,应进一步加大健康教育力度,加强孕产妇保健手册的管理和规范运转,加强初筛实验室和快速检测点的管理,完善分娩登记。     

2198例孕产妇HIV监测结果分析

目的了解孕产妇艾滋病病毒(HIV)感染状况,为预防艾滋病母婴传播工作提供依据。方法按照《全国艾滋病哨点监测实施方案(试行)》要求开展调查采样工作,HIV检测采用ELISA筛查和蛋白印迹(WB)法确认。结果共调查2198名孕产妇,其艾滋病知识总知晓率为74.55%。检出2例HIV抗体阳性者,HIV抗体阳性率为0.91‰。结论对孕产妇HIV进行监测,可掌握当地孕产妇人群中HIV的感染状况,以及她们对艾滋病防治知识的知晓情况。加强宣传教育,早期发现、早期管理HIV阳性孕妇,进行药物干预,可有效地降低HIV感染率阻止母婴垂直传播。     

Increase coverage of HIV and AIDS services in Myanmar

Myanmar is experiencing an HIV epidemic documented since the late 1980s. The National AIDS Programme national surveillance ante-natal clinics had already estimated in 1993 that 1.4% of pregnant women were HIV positive, and UNAIDS estimates that at end 2005 1.3% (range 0.7–2.0%) of the adult population was living with HIV. While a HIV surveillance system has been in place since 1992, the programmatic response to the epidemic has been slower to emerge although short- and medium-terms plans have been formulated since 1990. These early plans focused on the health sector, omitted key population groups at risk of HIV transmission and have not been adequately funded. The public health system more generally is severely under-funded.