1225例HIV/AIDS患者流行病学特征分析

目的:了解来陕西地区就诊的人类免疫缺陷病毒/艾滋病(Human immunodeficiency virus/Acquired immuno deficiency syndrome,HIV/AIDS)患者感染状况、流行特征。方法:收集来我院就诊的HIV/AIDS患者的基本信息,对其流行病学资料统计分析。结果:在调查的1225例HIV/AIDS患者中,男性占83.51%,平均年龄为(35.55±11.61)岁,50.98%为农民,小学及以下学历占33.55%,经血液途径感染250例,经性传播途径感染916例,其中同性性传播337例,经母婴垂直传播16例,就诊时CD4+T淋巴细胞计数平均值为(222.82±190.49)个/μL,56%的HIV/AIDS患者采用的抗病毒方案为齐多夫定(Zidovudine,AZT)/替诺福韦(Tenofovir Disoproxil Fumarate,TDF)+拉米夫定(Lamivudine,3TC)+依非韦伦(Efavirenz,EFV)方案。结论:陕西地区HIV/AIDS感染人数呈上升趋势,且年轻化加剧,同性性传播比例大幅增加。虽然治疗较为及时,应进一步在高危人群中积极宣传防艾知识与措施。     

The use of operational modeling of HIV/AIDS in a systems approach to public health decision making.

Compartmental models of infectious diseases readily represent known biological and epidemiological processes, are easily understood in flow-chart form by administrators, are simple to adjust to new information, and lend themselves to routine statistical analysis such as parameter estimation and model fitting. Technical results are immediately interpretable in epidemiological and public health terms. Deterministic models are easily stochasticized where this is important for practical purposes. With HIV/AIDS, serial data on both HIV prevalence and AIDS morbidity have been available from San Francisco. Assuming the distribution of the incubation period to be biologically stable, statistical analysis is quite feasible in other regions, even those with no reliable HIV data. Transmission rates must be estimated locally. It is also often possible to estimate the effective size of a population subgroup at risk, from population data on AIDS morbidity only. Computer simulation provides estimates of the evolving pattern of both HIV prevalence and AIDS morbidity. Some public health questions can be answered only by appropriately formulated stochastic models.     

HIV/AIDS knowledge, women's education, epidemic severity and protective sexual behaviour in low- and middle-income countries

A fundamental public health strategy to reduce the risk of HIV/AIDS is to increase levels of awareness and knowledge about the disease. Although knowledge about HIV/AIDS and protective sexual behaviour are linked theoretically, relatively little is known about their empirical relationship. Using Demographic and Health Survey data from 23 low- and middle-income countries, this study used multilevel logistic regression models: to examine cross-national variability in the relationship between HIV/AIDS knowledge and protective behaviour (condom use and restricted sex); to investigate the moderating influences of women's educational attainment on this relationship; and to test the extent to which severity of the HIV/AIDS epidemic accounts for cross-national variability in the association between HIV/AIDS knowledge and protective behaviour. There was an association between increased knowledge of HIV/AIDS and condom use that varied in strength and form cross-nationally. This cross-national variation was accounted for partially by the socioeconomic characteristics of women resident in the study countries and between-country differences in the severity of the HIV epidemic. While education modified the association between HIV/AIDS knowledge and protective behaviour--stronger associations at lower levels of education--epidemic severity exerted a stronger influence on behaviour than any other characteristic. Finally, this study indicates that protective sexual practices are disturbingly low. In eight of 23 countries, overall levels of condom use to prevent STDs and HIV/AIDS were less than 5.0%. Waiting for the spread of HIV/AIDS infection to change sexual practices in low- and middle-income countries will result in dramatic unnecessary suffering.     

HIV-1 Transmission during Early Infection in Men Who Have Sex with Men: A Phylodynamic Analysis

Background

Conventional epidemiological surveillance of infectious diseases is focused on characterization of incident infections and estimation of the number of prevalent infections. Advances in methods for the analysis of the population-level genetic variation of viruses can potentially provide information about donors, not just recipients, of infection. Genetic sequences from many viruses are increasingly abundant, especially HIV, which is routinely sequenced for surveillance of drug resistance mutations. We conducted a phylodynamic analysis of HIV genetic sequence data and surveillance data from a US population of men who have sex with men (MSM) and estimated incidence and transmission rates by stage of infection.

Methods and Findings

We analyzed 662 HIV-1 subtype B sequences collected between October 14, 2004, and February 24, 2012, from MSM in the Detroit metropolitan area, Michigan. These sequences were cross-referenced with a database of 30,200 patients diagnosed with HIV infection in the state of Michigan, which includes clinical information that is informative about the recency of infection at the time of diagnosis. These data were analyzed using recently developed population genetic methods that have enabled the estimation of transmission rates from the population-level genetic diversity of the virus. We found that genetic data are highly informative about HIV donors in ways that standard surveillance data are not. Genetic data are especially informative about the stage of infection of donors at the point of transmission. We estimate that 44.7% (95% CI, 42.2%–46.4%) of transmissions occur during the first year of infection.

Conclusions

In this study, almost half of transmissions occurred within the first year of HIV infection in MSM. Our conclusions may be sensitive to un-modeled intra-host evolutionary dynamics, un-modeled sexual risk behavior, and uncertainty in the stage of infected hosts at the time of sampling. The intensity of transmission during early infection may have significance for public health interventions based on early treatment of newly diagnosed individuals. Please see later in the article for the Editors'' Summary     

HIV/AIDS epidemic in Eastern Europe: Recent developments in the Russian Federation and Ukraine among women

Background: The Russian Federation and the Ukraine are among the Eastern European countries with the fastest growing number of cases of HIV. According to data from the Joint United Nations Program on HIV/AIDS, nearly 90% of newly reported HIV diagnoses in Eastern Europe in 2006 were from the Russian Federation (66%) and the Ukraine (21%). A growing number of women are infected with HIV. The impact of gender on HIV/AIDS is an important factor in understanding the development and evolution of the HIV/AIDS epidemic in Eastern Europe.Objective: The aim of this study was to assess the importance of integrating gender consideration into the creation of HIV programs and to examine the effect of gender on HIV/AIDS.Methods: Reported HIV/AIDS cases from the official epidemiological register of the Ukrainian Centre for AIDS Prevention alongside data from the Russian Federal AIDS Center were analyzed. Joint United Nations Program on HIV/AIDS country fact sheets were reviewed and analyzed, and this information was supplemented with published HIV prevalence and sexually transmitted disease case reporting information, unpublished reports, and expert evaluations.Results: Of the newly registered cases of HIV, the proportion of women rose from 13.0% in 1995 to 44.0% in 2006 in the Russian Federation, and from 37.2% in 1995 to 41.9% in 2006 in the Ukraine. There has also been a considerable increase in mother-to-child transmission of HIV since 1995. Between 1987 and 1994, the proportion of children among the people newly infected with HIV in the Ukraine was 2.2%; in 2006 it was 17.6%. In 2006, 16,078 new HIV cases were registered in the Ukraine and 39,652 new HIV cases in the Russian Federation. Large increases in the number of HIV-infected women were reported from both countries.Conclusions: The data examined in this study suggest subregional differences in the magnitude of the HIV/AIDS epidemic in the Russian Federation and the Ukraine and the importance of the impact of gender on the rapid spread of the HIV/AIDS epidemic among women and women of child-bearing age. To protect women from HIV infection, it is important to find ways to empower them by implementing policies and specific prevention measures that increase their access to knowledge about HIV/AIDS; the empowerment of women is vital to reversing the HIV/AIDS epidemic.     

AIDS now

Two philosphers from the University of Helsinki argue that, despite beliefs to the contrary in the Western world, AIDS is no longer predominantly a problem limited to homosexuals. First they clarify this claim by presenting epidemiological data. They then consider three ethical issues that have resulted from fearful public reaction to the rapid spread of AIDS: discrimination against those infected with the human immunodeficiency virus (HIV); proposed legal restrictions on personal choices, especially sexual; and screening for HIV antibodies without consent. The H?yrys then discuss whether there is a right not to know one's HIV status. Their essay concludes with suggestions of three ways to fight the spread of AIDS that should be implemented immediately: more support for AIDS research, organization of sociomedical actions such as information campaigns to slow the spread of the disease, and enactment of antidiscrimination legislation.     

University students' knowledge of, and attitudes towards, hiv and AIDS, homosexuality and sexual risk behaviour: a questionnaire survey in two finnish universities

Summary This study describes Finnish university students' knowledge and attitudes towards HIV and AIDS, homosexuality and sexual risk behaviour. Finnish-speaking students were randomly selected from all registered students at two universities in Finland (N=9715, n=950). The data were collected by using a modified version of the State University of New York at Buffalo School of Nursing AIDS Study Questionnaire on sexual risk behaviour developed by Held and Chng. The total response rate was 35% (n=333). The data were analysed using quantitative statistical methods. Normally distributed data were analysed by t-test and one-way ANOVA, with Bonferroni corrections. Non-normally distributed data were analysed using the Mann-Whitney U-test and Kruskal-Wallis test, followed by a post-hoc test. The majority of students were familiar with HIV and AIDS, including its mode of transmission. However, there were still some misconceptions concerning HIV and AIDS. The oldest students and women had a more positive attitude towards people living with HIV and AIDS (PLWHA). Of patients with HIV or AIDS, intravenous drug users were perceived most negatively. Male students had more homophobic attitudes. Students who reported that religion had an important role in their lives had significantly stricter attitudes towards sexual risk behaviour. Students' knowledge correlated positively with general attitudes towards HIV and AIDS. Knowledge about HIV and AIDS will lead to more positive attitudes towards HIV and AIDS as a disease, towards those infected as well as homosexual people. There is a need to focus on preventive health care and sexual health promotion by educating young people and changing their attitudes towards sexual risk behaviour.     

Higher Risk Perception of HIV than of Chlamydia and HPV among Secondary School Students in Two German Cities

Background

Chlamydia and genital human papillomavirus (HPV) are the two most common sexually transmitted infections (STIs) among teens and young adults in industrialised countries. The majority of adolescents, however, have limited or no knowledge of these infections. Within the context of a cross-sectional survey on awareness and knowledge of sexually transmitted infections, secondary school students attending the 8th grade and above in Bremen and Bremerhaven, two cities in northern Germany, were asked to rate the risk of peers to get infected with HIV, HPV or chlamydia.

Methods

Between October and December 2011, students aged 12–20 years completed an anonymous, self-administered questionnaire at their school. In addition to answering questions on awareness and knowledge of sexually transmitted infections, all students were also asked to rate the risk of peers to get infected with HIV, HPV or chlamydia. Furthermore, those reporting ever having sexual intercourse were asked to rate their own risk of getting infected with each of the three infections.

Results

1,148 students, 55% female, completed the questionnaire. 27% of the students reported having had sexual intercourse. 68% of all students rated the risk of same-aged students to get infected with HIV/AIDS as high/medium. The corresponding proportions for HPV and chlamydia were 19 and 25% respectively. Those reporting ever having sexual intercourse generally perceived their own risk of getting infected with HIV, chlamydia or HPV as lower than that of their peers.

Conclusion

Generally, the risk of getting infected with HIV was perceived as being higher than that of getting infected with HPV or chlamydia, most likely due to the fact that the students were more aware of HIV than of the other two infections. Efforts should be made to improve awareness and knowledge of HPV and chlamydia among school going adolescents, and to make them realize that these are common infections that are preventable.     

UN warns that AIDS deaths are set to reach record level

The Joint United Nations Programme on HIV/AIDS (UNAIDS) warns that AIDS deaths are set to reach a record level during the year 1999. Estimates from UNAIDS reveal that 2.6 million people will die from diseases related to HIV and AIDS during 1999--a higher global total than any year since the beginning of the epidemic. In addition, 32.4 million adults and 1.2 million children are estimated to be living with HIV infection by the end of 1999. About 95% of those infected live in the developing world, and this proportion was predicted to rise even further as infection rates continued to rise in countries where poverty, poor health systems, and limited resources for prevention and care fueled the spread of the virus. The highest prevalence of the infection is seen in sub-Saharan Africa; close to 70% of the global total of HIV-positive people come from this region. However, the challenge also remains in industrialized countries, where unsafe sexual behavior and drug injection are practiced.     

A stochastic model for the development of an AIDS epidemic in a heterosexual population.

A non-age-dependent model, describing the evolution of a bisexual population, is developed in this paper and applied to projecting an AIDS epidemic in a heterosexual population. Included in the formulation are frequency- and non-frequency-dependent rules of partnership formation as well as five states of HIV disease, affecting the probability of infection per sexual contact. Results from computer experiments, designed to study the development of an AIDS epidemic in a heterosexual population fed by single males with a 50% prevalence of HIV infection prior to becoming active in heterosexual partnerships, are reported. In these experiments, the only source of HIV infection for females was sexual contacts with infected males within partnerships. Data on the probability of infection per sexual contact with an infected partner and the number of sexual contacts per month were incorporated into the model. However, the numbers used for the initial population of singles, couples, and those becoming sexually active per month were hypothetical. Even though the prevalence of HIV infection among males entering heterosexual partnerships was high, after 30 years the projected prevalence of HIV infection among females ranged from about 10 to 15% depending in part on the expected duration of partnerships and on whether the frequency- or non-frequency-dependent model was used. In these experiments, solutions of the embedded, nonlinear, deterministic equations for the incidence of HIV infection and the cumulative number of deaths due to AIDS proved to be good measures of central tendency for the sample functions of the stochastic population process.     

HIV prevalence in blood donors in urban and in rural areas of the Federal Republic of Germany

HIV infection rates in blood donors from the FRG were compared with the prevalence in donors from Berlin to obtain information on the HIV infections in donors of rural versus urban origin. The HIV prevalences decrease similarly in the first years of testing, although on different levels. They are lower in rural areas by a factor of 15 in the first year and of 10 thereafter. The modes of infectivity in both groups are similar although drug abuse seems to be more frequent amongst infected donors of urban areas. Ninety percent of the infected donors are either persons at risk or sexual partners of risk persons. During the observed time period there seems to be a trend from homo-/bisexuality and i.v. drug abuse to heterosexual contacts with persons at risk as the mode of infection. In conjunction with the stabile low and constant rates of infection for the last two years, these data indicate that the risk of HIV infection by blood transfusion is reduced to an acceptable minimum even in urban areas.     

Epidemiological and statistical aspects of the AIDS epidemic: introduction

In 1988, a government working party studied estimates of incidence and prevalence of numbers of acquired immunodeficiency syndrome (AIDS) cases. They investigated a series of epidemiological, statistical and mathematical problems associated with predicting trends in incidences of AIDS. This paper introduces a series of papers that give a fuller and more technical exposition of the appendixes of that working party report. The papers provide a brief background to the current state of knowledge on the epidemiology of the infection and the disease; a deterministic model for human immunodeficiency virus (HIV) transmission in the male homosexual community in England and Wales is introduced. Back-projection methods are studied in two papers, following the distribution of the incubation period of the disease. The concept of minimum size of the epidemic is introduced. Mathematical functions to describe the spread of HIV infection are refined by using past trends in the incidence of AIDS to estimate values for some parameters. Survival times for AIDS patients from the point of diagnosis are considered and evidence for changes in male homosexual sexual behaviour is studied; lag-time from the point of diagnosis to the report of the case is also examined. There is a comparative analysis of the AIDS epidemic in various European countries. The incubation period of HIV in patients with haemophilia A and B infections and the problems associated with making predictions for different at-risk groups or small subgroups based on geographical area are discussed. Reasons for fluctuation between the number of reported cases from month to month are provided.     

The HIV epidemic: medical and social challenges

The sudden appearance, rapid spread, and devastating clinical impact of HIV infection in Africa, Europe and North America has created a medical problem unprecedented in the modern era. HIV is sexually transmitted, afflicts sexual and racial minorities in developed countries, and appears likely to be fatal and incurable in a majority of infected people. Its epidemiology (transmission and natural history) and clinical manifestations have been well described, but treatment of HIV remains minimally effective, creating only a short respite from progressive deterioration. In the absence of effective vaccination, HIV will continue to spread, abetted by a long period of asymptomatic carriage during which carriers are infectious. It has spread internationally to most undeveloped countries aided by fear and ignorance. The problem will resist simple technological solutions and adversely impact the lives of tens of millions of people in these areas over the next several decades. In developed countries HIV will strain medical resources and kill several million people before the end of the century. Despite the tremendous problems created by the AIDS epidemic, it has driven a remarkable expansion of virologic and immunologic understanding which promises to ultimately lead to control of not only AIDS, but a variety of other serious diseases. The following reviews of pivotal issues in AIDS research document this progress.     

The penetration of HIV into the population of Moscow homosexuals and its spread

The article deals with the epidemiological investigation of cases of HIV infection among the population of homosexuals. 119 representatives of this population were checked in their sexual contacts; of these, 13 persons proved to be infected with HIV. HIV infection was found to penetrate into the homosexual population of the USSR from the countries of Western Europe and the USA by sexual route. In 1988 the intensive spread of this infection began.     

Reconstructing the Dynamics of HIV Evolution within Hosts from Serial Deep Sequence Data

At the early stage of infection, human immunodeficiency virus (HIV)-1 predominantly uses the CCR5 coreceptor for host cell entry. The subsequent emergence of HIV variants that use the CXCR4 coreceptor in roughly half of all infections is associated with an accelerated decline of CD4+ T-cells and rate of progression to AIDS. The presence of a ‘fitness valley’ separating CCR5- and CXCR4-using genotypes is postulated to be a biological determinant of whether the HIV coreceptor switch occurs. Using phylogenetic methods to reconstruct the evolutionary dynamics of HIV within hosts enables us to discriminate between competing models of this process. We have developed a phylogenetic pipeline for the molecular clock analysis, ancestral reconstruction, and visualization of deep sequence data. These data were generated by next-generation sequencing of HIV RNA extracted from longitudinal serum samples (median 7 time points) from 8 untreated subjects with chronic HIV infections (Amsterdam Cohort Studies on HIV-1 infection and AIDS). We used the known dates of sampling to directly estimate rates of evolution and to map ancestral mutations to a reconstructed timeline in units of days. HIV coreceptor usage was predicted from reconstructed ancestral sequences using the geno2pheno algorithm. We determined that the first mutations contributing to CXCR4 use emerged about 16 (per subject range 4 to 30) months before the earliest predicted CXCR4-using ancestor, which preceded the first positive cell-based assay of CXCR4 usage by 10 (range 5 to 25) months. CXCR4 usage arose in multiple lineages within 5 of 8 subjects, and ancestral lineages following alternate mutational pathways before going extinct were common. We observed highly patient-specific distributions and time-scales of mutation accumulation, implying that the role of a fitness valley is contingent on the genotype of the transmitted variant.     

Parasite infections in AIDS

'Illnesses no one's got' was the epidemiological clue that led to the identification of AIDS as a new disease in 1981 when a rare infectious organism Pneumocystis carinii was seen in previously healthy homosexuals. Since then a wide range of parasite infections has been recognized in AIDS patients. However, these patients are not susceptible to just any passing parasite. The human immunodeficiency virus (HIV) produces a specific immune defect and only parasites that can exploit that defect will be able to flourish. In this review Diana Lockwood and Jonathan Weber explore the spectrum of parasite diseases recognized in AIDS and also consider those parasites that occur infrequently in AIDS. Analysis of parasitic infections that AIDS patients do not suffer from will yield valuable information about immune recognition and handling of these parasites.     

The epidemiology of human immunodeficiency virus in South Africa

We review the epidemiology of human immunodeficiency virus (HIV) in South Africa where the prevalence of HIV infection is among the highest in the world. The epidemic reached South Africa relatively recently but the prevalence of infection has increased rapidly and there are significant differences among provinces. Although few 15-year-old people are infected the prevalence increases rapidly with age thereafter, especially among women. The prevalence of herpes simplex virus type 2 exceeds that of HIV and curable sexually transmitted infections are common. 'Circular migration' may help to explain the high rates and rapid spread of HIV in the region. The incidence of tuberculosis has increased dramatically as a result of the HIV epidemic. Antiretroviral therapy for the prevention of vertical transmission has been shown to be effective in local conditions but transmission through breast-feeding remains problematical. While some epidemiological models have been developed, much more needs to be done in this regard in order to plan, coordinate and evaluate an effective response to the epidemic. We conclude by discussing some of the research that is needed and steps that could be taken to reduce the continued spread of the infection.     

Using the Kalman filter and dynamic models to assess the changing HIV/AIDS epidemic

Many factors, including therapy and behavioral changes, have modified the course of the HIV/AIDS epidemic in recent years. To include these modifications in HIV/AIDS models, in the absence of appropriate external data sources, changes over time in the parameters can be incorporated by a recursive estimation technique such as the Kalman filter. The Kalman filter accounts for stochastic fluctuations in both the model and the data and provides a means to assess any parameter modifications included in new observations. The Kalman filter approach was applied to a simple differential model to describe the observed HIV/AIDS epidemic in the homo/bisexual male community in Paris (France). This approach gave quantitative information on the time-evolution of some parameters of major epidemiological significance (average transmission rate, mean incubation rate, and basic reproduction rate), which appears quite consistent with the recent epidemiological literature.     

广西靖西县1997—2012年HIV/AIDS流行病学特征分析

目的了解广西靖西县1997—2012年HIV/AIDS流行病学状况,分析流行趋势,为制定艾滋病防治措施提供科学依据。方法采用描述流行病学分析方法,对靖西县1997—2012年艾滋病疫情监测资料进行分析。结果靖西县1997—2012年累计报告HIV/AIDS 147例,其中HIV感染者60例,AIDS病人47例,死亡40例;男性95例,女性52例,男女性别比为1.83∶1;以20~49岁青壮年为主,这些年龄组发病率为3.24/10万;传播途径以性接触传播为主,占90.48%;其次为静脉注射毒品传播,占6.80%。结论靖西县艾滋病流行近年呈明显上升趋势,艾滋病已经从高危人群向普通人群扩散传播,性接触传播已经成为艾滋病的主要传播途径,应加强对高危人群性行为的干预,遏制艾滋病传播蔓延。     

Levels of spending and resource allocation to HIV programs and services in Latin America and the Caribbean

Background

An estimated 1.86 million people are living with HIV in Latin America and the Caribbean (LAC). The region is comprised of mainly middle-income countries with steady economic growth while simultaneously there are enormous social inequalities and several concentrated AIDS epidemics. This paper describes HIV spending patterns in LAC countries including analysis of the levels and patterns of domestic HIV spending from both public and international sources.

Methods and Findings

We conducted an extensive analysis of the most recently available data from LAC countries using the National AIDS Spending Assessment tool. The LAC countries spent a total of US$ 1.59 billion on HIV programs and services during the latest reported year. Countries providing detailed information on spending showed that high percentages are allocated to treatment and care (75.1%) and prevention (15.0%). Domestic sources accounted for 93.6 percent of overall spending and 79 percent of domestic funds were directed to treatment and care. International funds represented 5.4 percent of total HIV funding in the region, but they supplied the majority of the effort to reach most-at-risk-populations (MARPs). However, prevalence rates among men who have sex with men (MSM) still reached over 25 percent in some countries.

Conclusions

Although countries in the region have increasingly sustained their response from domestic sources, still there are future challenges: 1) The growing number of new HIV infections and more people-living-with-HIV (PLWH) eligible to receive antiretroviral treatment (ART); 2) Increasing ART coverage along with high prices of antiretroviral drugs; and 3) The funding for prevention activities among MARPs rely almost exclusively on external donors. These threats call for strengthened actions by civil society and governments to protect and advance gains against HIV in LAC.