Can we reverse the HIV/AIDS pandemic with an expanded response?

Immunohematological Outcome Among Adult HIV Patients Taking Highly Active Antiretroviral Therapy for at Least Six Months in Yabelo Hospital, Borana, Ethiopia

Background

Immunohematological abnormalities among human immunodeficiency virus-infected patients are common abnormalities associated with severe depletion of the immune system, covering a stage of acute syndrome to an advanced disease. The greatest impact was observed in the low- and middle-income countries. However, in Ethiopia, little attention has been paid, and only limited published information exists regarding immunohematological abnormalities among individuals receiving highly active antiretroviral treatment.

Objective

This study aimed to assess changes in immunological and hematological parameters in HIV-infected patients receiving HAART for at least six months at the antiretroviral therapy clinic of Yabelo Hospital, Borena, Ethiopia.

Methods

A cross-sectional study was conducted from February to July 2021 using convenient sampling to recruit 333 participants. Sociodemographic data and clinical characteristics were collected using a pretested questionnaire. Baseline data were extracted from medical records and after six month immunohematological measurements were performed on blood samples collected during the study period. Data analysis was performed using SPSS version 25. Descriptive analysis was performed, and the results are presented as numbers and percentages or means ± SD. A paired t-test was used to compare the mean values of the immunohematological parameters before and after six of taking HAART. Statistical significance was set at P < 0.05.

Results

The prevalence of anemia, leucopenia, neutropenia, lymphopenia and thrombocytopenia were 47.4%, 73.3%, 58.3%, 76.9% and 3.3% before initiation of HAART and 23.1%, 36.4%, 23.4%, 35.7% and 2.4% after initiation of HAART, respectively; Compared to baseline, there was also a significant decrease in the rate of Immunosuppression (CD4 < 350) from 62.2% at base line to 20.7% after HAART initiation.

Conclusion

Immunohematological profile of the patients improved after the initiation of HAART. The observation of large proportion of immunosuppressed individuals at baseline warrants advocating for HIV testing in the pastoralist community so that infected patients could benefit from early initiation of HAART.

A multicountry European study on Succeed: a general quality improvement tool in HIV prevention

The context-sensitive nature of the European HIV epidemic (e.g. differences in key populations, prevention settings, resource commitments) makes it challenging to monitor and evaluate HIV prevention and sexual health promotion programs. Systematic quality improvement (QI) tools and quality indicators adapted to HIV prevention are not widely known or implemented. The European 'Quality Action' introduced five such tools in 26 countries involving 45 nongovernmental and governmental organizations during 2014-2016. Approximately, half of the organizations used the tool 'Succeed'. This study aims to describe challenges and supportive factors in its use, and answers the research question if Succeed can be applied as a general QI tool despite the high contextuality of the European HIV prevention field. Mixed method research was conducted: data from quantitative pre- and post-training and implementation surveys were triangulated with qualitative data from multiple data sources analysed inductively. In a second analytical step, Chaudoir's evidence-based framework on implementation of innovations (2013) guided the data analysis on five levels: policy, organization, functionality of the tool, results and perceived innovations. Succeed contributed to goal and result orientation, facilitated stakeholders' participation and contributed to organizational development. Succeed was used in similar ways and with similar results across different policy contexts, types of organizations, target groups and interventions. Contributing factors for sustainable implementation were supporting environments, sufficient resources and a strategy for training tool users. Findings strongly support the use of Succeed as a general QI tool to monitor, document, adapt and improve HIV prevention and sexual health promotion work across Europe.

Evolving HIV epidemics: the urgent need to refocus on populations with risk

Purpose of review

To explore the comparative importance of HIV infections among key populations and their intimate partners as HIV epidemics evolve, and to review implications for guiding responses.

Recent findings

Even as concentrated epidemics evolve, new infections among current and former key population members and their intimate partners dominate new infections. Prevalent infections in the general population grow primarily because of key population turnover and infections among their intimate partners. In generalized epidemic settings, data and analysis on key populations are often inadequate to assess the impact of key population-focused responses, so they remain limited in coverage and under resourced. Models must incorporate downstream infections in comparing impacts of alternative responses.

Summary

Recognize that every epidemic is unique, moving beyond the overly simplistic concentrated/generalized epidemic paradigm that can misdirect resources. Guide HIV responses by gathering and using locally relevant data, understanding risk heterogeneity, and applying modeling at both national and sub-national levels to optimize resource allocations among different populations for greatest impact. Translate this improved understanding into clear, unequivocal advice for policymakers on where to focus for impact, breaking them free of the generalized/concentrated paradigm limiting their thinking and affecting their decisions.

Systematic review: a review of adolescent behavior change interventions [BCI] and their effectiveness in HIV and AIDS prevention in sub-Saharan Africa

BACKGROUND

Despite sub-Saharan Africa [SSA] constituting just 12% of the world's population, the region has the highest burden of HIV with 70% of HIV infection in general and 80% of new infections among young people occuring in the region. Diverse intervention programmes have been implemented among young people but with minimal translation to behavior change. A systematic review of Behavior Change Interventions [BCI] targeting adolescents in SSA was therefore conducted with the objective of delineating this intervention vis-a-vis efficacy gap.

METHODS

From April to July 2015 searches were made from different journals online. Databases searched included MEDLINE, EBSCOhost, PsychINFO, Cochrane, and Google Scholar; Cambridge and Oxford journal websites, UNAIDS and WHO for studies published between 2000 and 2015. After excluding other studies by review of titles and then abstracts, the studies were reduced to 17. Three of these were randomized trials and five quasi-experimental. Overall interventions included those prescribing life skills, peer education [n = 6] and community collaborative programmes. The main study protocol was approved by the University of Malawi College of Medicine Ethics Committee on 30th June 2016 [ref #: P.01/16/1847. The review was registered with PROSPERO [NIH] in 2015.

RESULTS

The review yielded some 200 titles and abstracts, 20 full text articles were critically analysed and 17 articles reviewed reflecting a dearth in published studies in the area of psychosocial BCI interventions targeting adolescents in SSA. Results show that a number of reviewed interventions [n = 8] registered positive outcomes in both knowledge and sexual practices.

CONCLUSIONS

The review demonstrates a paucity of psychosocial BCI studies targeting adolescents in SSA. There are however mixed findings about the effectiveness of psychosocial BCI targeting adolescents in SSA. Other studies portray intervention effectiveness and others limited efficacy. Peer education as an intervention stands out as being more effective than other psychosocial regimens, like life skills, in facilitating HIV risk reduction. There is therefore need for further research on interventions employing peer education to substantiate their potential efficacy in HIV risk reduction among adolescents.

PROSPERO REGISTRATION NUMBER

CRD42015019244, available from http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42015019244 .

A catastrophe in the 21st century: the public health situation in South Africa following HIV/AIDS

During the early 1900s, African populations in South Africa were subject to very widespread infections which especially affected the young. This resulted in high mortality rates and a low life expectancy of 20-25 years. By the mid-century, mortality rates from infections had decreased considerably. Moreover, the occurrences of non-communicable diseases, even in urban areas, remained very low. In the 1970s, the proportion of Africans aged 50 or over that reached 70 years was 38.5%, higher than that in the juxtaposed white population, which was 35.5%. And by 1985, the life expectancy of Africans reached 61 years for males and 63 years for females, probably the highest in sub-Saharan African populations. Since then, however, the African continent has been devastated by the AIDS epidemic. In 2001, HIV was responsible for the death of a third of the African population in South Africa, but even higher proportions prevailed in Botswana and in Tanzania. The calamitous advent of the HIV infection has caused major falls in life expectancy, in the case of Africans in South Africa reducing this to just 43 years. With little hope of meaningful changes occurring in sexual habits or of an early vaccine becoming available, the infectionís high morbidity/mortality burden is likely to continue.

Behaviour and communication change in reducing HIV: is Uganda unique?

The clearest example of declines in HIV prevalence and changes in sexual behaviour comes from Uganda. Are there lessons to learn for other countries or is Uganda unique? In this paper, we assess the epidemiological and behavioural data on Uganda comparatively to other African countries and then analyse data from other populations where HIV has declined. In Uganda, HIV prevalence declined from 21% to 9.8% from 1991-1998, there was a reduction in non-regular sexual partners by 65% and greater levels of communication about AIDS and people with AIDS through social networks, unlike the comparison countries. There is evidence of a basic population level response initiated at community level, to avoid risk, reduce risk behaviours and care for people with AIDS. The basic elements-a continuum of communication, behaviour change and care-were integrated at community level. They were also strongly supported by distinctive Ugandan policies from the 1980s. We identify a similar, early behaviour and communication response in other situations where HIV has declined: Thailand, Zambia and the US Gay community. In Thailand, visits to sex workers decreased by 55% and non-regular partners declined from 28% to 15% (1990-1993): as important as the '100% condom use policy'. Similarly, in Zambia and Ethiopia risk behaviour has decreased and analysis of Sexually Transmitted Disease (STD) rates among Gay populations in the USA shows a decline from as early as 1985 in White Gay populations, with later declines in Hispanic and Black Gay populations. These responses preceded and exceeded HIV prevention. However, where they were built on by distinctive HIV policies, HIV prevention has been scaled and led to national level declines in HIV. It is not easy to transfer the lessons of these successes. They require real social and political capital in addition to financial capital. Nevertheless, similar characteristics are present in community responses in Africa, Asia and USA, and even in fragmented signs of HIV declines in other African cities. Only in a few situations has this behaviour and communication process been recognised, mobilised and built on by HIV prevention policy. Where this has occurred, HIV prevention success has been greater than biomedical approaches or methods introduced from outside. It represents a social vaccine for HIV from Africa, and is available now.

Replicating impact of a primary school HIV prevention programme: primary school action for better health, Kenya

School-based programmes to combat the spread of HIV have been demonstrated to be effective over the short-term when delivered on a small scale. The question addressed here is whether results obtained with small-scale delivery are replicable in large-scale roll-out. Primary School Action for Better Health (PSABH), a programme to train teachers to deliver HIV-prevention education in upper primary-school grades in Kenya demonstrated positive impact when tested in Nyanza Province. This article reports pre-, 10-month post- and 22-month post-training results as PSABH was delivered in five additional regions of the country. A total of 26 461 students from 110 primary schools in urban and rural, middle- and low-income settings participated in this repeated cross-sectional study. Students ranged in age from 11 to 16 years, were predominantly Christian (10% Muslim), and the majority were from five different ethnic groups. Results demonstrated positive gains in knowledge, self-efficacy related to changes in sexual behaviours and condom use, acceptance of HIV+ students, endorsement of HIV-testing and behaviours to post-pone sexual debut or decrease sexual activity. These results are as strong as or stronger than those demonstrated in the original impact evaluation conducted in Nyanza Province. They support the roll-out of the programme across Kenyan primary schools.

Development, calibration and performance of an HIV transmission model incorporating natural history and behavioral patterns: application in South Africa

Understanding HIV transmission dynamics is critical to estimating the potential population-wide impact of HIV prevention and treatment interventions. We developed an individual-based simulation model of the heterosexual HIV epidemic in South Africa and linked it to the previously published Cost-Effectiveness of Preventing AIDS Complications (CEPAC) International Model, which simulates the natural history and treatment of HIV. In this new model, the CEPAC Dynamic Model (CDM), the probability of HIV transmission per sexual encounter between short-term, long-term and commercial sex worker partners depends upon the HIV RNA and disease stage of the infected partner, condom use, and the circumcision status of the uninfected male partner. We included behavioral, demographic and biological values in the CDM and calibrated to HIV prevalence in South Africa pre-antiretroviral therapy. Using a multi-step fitting procedure based on Bayesian melding methodology, we performed 264,225 simulations of the HIV epidemic in South Africa and identified 3,750 parameter sets that created an epidemic and had behavioral characteristics representative of a South African population pre-ART. Of these parameter sets, 564 contributed 90% of the likelihood weight to the fit, and closely reproduced the UNAIDS HIV prevalence curve in South Africa from 1990–2002. The calibration was sensitive to changes in the rate of formation of short-duration partnerships and to the partnership acquisition rate among high-risk individuals, both of which impacted concurrency. Runs that closely fit to historical HIV prevalence reflect diverse ranges for individual parameter values and predict a wide range of possible steady-state prevalence in the absence of interventions, illustrating the value of the calibration procedure and utility of the model for evaluating interventions. This model, which includes detailed behavioral patterns and HIV natural history, closely fits HIV prevalence estimates.

Health workforce contributions to health system development: a platform for universal health coverage

PROBLEM

In the 1970s, Thailand was a low-income country with poor health indicators and low health service coverage. The local health infrastructure was especially weak.

APPROACH

In the 1980s, measures were initiated to reduce geographical barriers to health service access, improve the health infrastructure at the district level, make essential medicines more widely available and develop a competent, committed health workforce willing to service rural areas. To ensure service accessibility, financial risk protection schemes were expanded.

LOCAL SETTING

In Thailand, district hospitals were practically non-existent in the 1960s. Expansion of primary health care (PHC), especially in poor rural areas, was considered essential for attaining universal health coverage (UHC). Nationwide reforms led to important changes in a few decades.

RELEVANT CHANGES

Over the past 30 years, the availability and distribution of health workers, as well as their skills and competencies, have greatly improved, along with national health indicators. Between 1980 and 2000 coverage with maternal and child health services increased substantially. By 2002, Thailand had attained UHC. Overall health system development, particularly an expanded health workforce, resulted in a functioning PHC system.

LESSONS LEARNT

A competent, committed health workforce helped strengthen the PHC system at the district level. Keeping the policy focus on the development of human resources for health (HRH) for an extended period was essential, together with a holistic approach to the development of HRH, characterized by the integration of different kinds of HRH interventions and the linking of these interventions with broader efforts to strengthen other health system domains.

Elimination of HIV in South Africa through expanded access to antiretroviral therapy: a model comparison study

BACKGROUND

Expanded access to antiretroviral therapy (ART) using universal test and treat (UTT) has been suggested as a strategy to eliminate HIV in South Africa within 7 y based on an influential mathematical modeling study. However, the underlying deterministic model was criticized widely, and other modeling studies did not always confirm the study's finding. The objective of our study is to better understand the implications of different model structures and assumptions, so as to arrive at the best possible predictions of the long-term impact of UTT and the possibility of elimination of HIV.

METHODS AND FINDINGS

We developed nine structurally different mathematical models of the South African HIV epidemic in a stepwise approach of increasing complexity and realism. The simplest model resembles the initial deterministic model, while the most comprehensive model is the stochastic microsimulation model STDSIM, which includes sexual networks and HIV stages with different degrees of infectiousness. We defined UTT as annual screening and immediate ART for all HIV-infected adults, starting at 13% in January 2012 and scaled up to 90% coverage by January 2019. All models predict elimination, yet those that capture more processes underlying the HIV transmission dynamics predict elimination at a later point in time, after 20 to 25 y. Importantly, the most comprehensive model predicts that the current strategy of ART at CD4 count ≤350 cells/µl will also lead to elimination, albeit 10 y later compared to UTT. Still, UTT remains cost-effective, as many additional life-years would be saved. The study's major limitations are that elimination was defined as incidence below 1/1,000 person-years rather than 0% prevalence, and drug resistance was not modeled.

CONCLUSIONS

Our results confirm previous predictions that the HIV epidemic in South Africa can be eliminated through universal testing and immediate treatment at 90% coverage. However, more realistic models show that elimination is likely to occur at a much later point in time than the initial model suggested. Also, UTT is a cost-effective intervention, but less cost-effective than previously predicted because the current South African ART treatment policy alone could already drive HIV into elimination. Please see later in the article for the Editors' Summary.

Individual- and school-level correlates of HIV testing among secondary school students in Kenya

The policy framework guiding Kenya's response to the AIDS epidemic identifies voluntary counseling and testing as crucial to risk reduction and HIV-preventive activities. Yet in Kenya, as in most sub-Saharan countries, voluntary testing rates are low, especially among young people. Using hierarchical linear models, we identify both individual- and teacher/school-level factors that affect voluntary HIV testing among secondary school students in Kenya. Results indicate that adolescents are more likely to test for HIV serostatus when they are knowledgeable about testing, have been involved in HIV/AIDS activities in primary school, have been provided with HIV information in secondary school, perceive themselves as at high risk of contracting HIV or know of someone infected with or who has died from HIV/AIDS, and have ever engaged in sexual intercourse. Barriers include fear of going to testing centers and being perceived as HIV-positive. Teacher/school-level characteristics are relevant for explaining rates of HIV testing, especially among girls. To encourage testing, policymakers should attend to teacher/school-level factors as well as individual characteristics of students.

The serologic decoy receptor 3 (DcR3) levels are associated with slower disease progression in HIV-1/AIDS patients

BACKGROUND/PURPOSE

The decoy receptor 3 (DcR3) is a member of the tumor necrosis factor receptor (TNFR) super-family. It counteracts the biological effects of Fas ligands and inhibits apoptosis. The goals of this study were to understand the associations between serologic DcR3 (sDcR3) levels and different human immunodeficiency virus type 1 (HIV-1) subtypes, as well as the AIDS disease progression.

METHODS

Serum samples from 61 HIV/AIDS patients, who had been followed up every 6 months for 3 years, were collected. sDcR3 levels were quantified using an enzyme immunoassay (EIA).

RESULTS

The sDcR3 levels in patients with HIV-1 subtype B were significantly higher than those in patients infected with subtype CRF01_AE (p < 0.001). In addition, multivariable linear mixed model analysis demonstrated that HIV-1 subtype B and slow disease progression were associated with higher levels of sDcR3, adjusting for potential predictors (p = 0.0008 and 0.0455, respectively).

CONCLUSION

HIV-1-infected cells may gain a survival advantage by activating DcR3, which prevents infected cell detection by the host immune system. These data indicate that the sDcR3 level is a biomarker for AIDS disease progression.

Prevention of sexually transmitted HIV infections through the President's Emergency Plan for AIDS Relief: a history of achievements and lessons learned

HIV prevention in the President's Emergency Plan for AIDS Relief (PEPFAR) began when both data on HIV prevalence and the toolbox of interventions for prevention of sexual transmission were relatively limited. PEPFAR's early focus was on scaling-up information, education, and communication programs that included messaging on abstinence for youth and faithfulness primarily through nongovernmental organizations, including faith-based organizations. Additional activities included condom promotion, distribution, and social marketing. In epidemics concentrated within key populations, PEPFAR's prevention efforts focused on a minimum package of services including outreach, information, education, and communication programs, STI treatment (where appropriate), and condom promotion and distribution. As more epidemiological data became available and with experience gleaned in these early efforts, the need for tailored and flexible approaches became evident. The next iteration of prevention efforts still emphasized behavioral interventions, but incorporated a sharper focus on key epidemic drivers, especially multiple partners; a data-driven emphasis on high transmission areas and populations, including prevention with people living with HIV; and a more strategic and coordinated approach at the national level. Recently, the paradigm for prevention efforts has shifted yet again. Evidence that biomedical interventions such as male circumcision, treatment for prevention of vertical and horizontal transmission, and treatment itself could lead to declines in incidence has refocused PEPFAR's prevention portfolio. New guidance on sexually transmitted HIV focuses on combination prevention, emphasizing biomedical, behavioral and structural approaches. Landmark speeches by the President and the Secretary of State and new ambitious targets for PEPFAR point toward a new goal: an AIDS-free generation.

Identifying virus-cell fusion in two-channel fluorescence microscopy image sequences based on a layered probabilistic approach

The entry process of virus particles into cells is decisive for infection. In this work, we investigate fusion of virus particles with the cell membrane via time-lapse fluorescence microscopy. To automatically identify fusion for single particles based on their intensity over time, we have developed a layered probabilistic approach. The approach decomposes the action of a single particle into three abstractions: the intensity over time, the underlying temporal intensity model, as well as a high level behavior. Each abstraction corresponds to a layer and these layers are represented via stochastic hybrid systems and hidden Markov models. We use a maxbelief strategy to efficiently combine both representations. To compute estimates for the abstractions we use a hybrid particle filter and the Viterbi algorithm. Based on synthetic image sequences, we characterize the performance of the approach as a function of the image noise. We also characterize the performance as a function of the tracking error. We have also successfully applied the approach to real image sequences displaying pseudotyped HIV-1 particles in contact with host cells and compared the experimental results with ground truth obtained by manual analysis.

Estimating the resources required in the roll-out of universal access to antiretroviral treatment in Zimbabwe

OBJECTIVES

To develop projections of the resources required (person-years of drug supply and healthcare worker time) for universal access to antiretroviral treatment (ART) in Zimbabwe.

METHODS

A stochastic mathematical model of disease progression, diagnosis, clinical monitoring and survival in HIV infected individuals.

FINDINGS

The number of patients receiving ART is determined by many factors, including the strategy of the ART programme (method of initiation, frequency of patient monitoring, ability to include patients diagnosed before ART became available), other healthcare services (referral rates from antenatal clinics, uptake of HIV testing), demographic and epidemiological conditions (past and future trends in incidence rates and population growth) as well as the medical impact of ART (average survival and the relationship with CD4 count when initiated). The variations in these factors lead to substantial differences in long-term projections; with universal access by 2010 and no further prevention interventions, between 370 000 and almost 2 million patients could be receiving treatment in 2030-a fivefold difference. Under universal access, by 2010 each doctor will initiate ART for up to two patients every day and the case-load for nurses will at least triple as more patients enter care and start treatment.

CONCLUSIONS

The resources required by ART programmes are great and depend on the healthcare systems and the demographic/epidemiological context. This leads to considerable uncertainty in long-term projections and large variation in the resources required in different countries and over time. Understanding how current practices relate to future resource requirements can help optimise ART programmes and inform long-term public health planning.

A MATHEMATICAL MODEL FOR COMBATING HIV/AIDS IN SOUTHERN AFRICA: WILL MULTIPLE STRATEGIES WORK?

A model for the transmission of HIV is proposed with the inclusion of prevention strategies, such as condom use, ARV drug treatment and voluntary counseling and testing. The model is used to predict the potential impact of the strategies that are currently being used to control HIV/AIDS. The model shows that reduction in the number of sexually contacts, by increasing condom use and avoidance of multiple sexual partners has a significant impact in reducing the transmission of the disease.

Assessment of population-level effect of Avahan, an HIV-prevention initiative in India

BACKGROUND

The aim of Avahan, the India AIDS Initiative, was to reduce HIV transmission in the general population through large-scale prevention interventions focused on high-risk groups. It was launched in 2003 in six states with a total population of 300 million and a high HIV burden. We assessed the population-level effect of the first phase of Avahan (2003-08).

METHODS

Population prevalence was estimated by use of adjustment factors from the national HIV sentinel surveillance data obtained annually from antenatal clinics. A mixed-effects multilevel regression model was developed to estimate the association between intervention intensity and population HIV prevalence trends, taking into account differences in the underlying epidemic trends in states and other potential confounders, and to estimate the number of HIV infections averted with Avahan.

FINDINGS

80 (61%) of 131 districts in the six Avahan states received funding from Avahan for HIV prevention, as the only or shared source. Greater intensity of Avahan, measured as amount of grant per HIV population (medians US$24-432 in the six states), was significantly associated with lower HIV prevalence in Andhra Pradesh (p=0·004), Karnataka (p=0·004), and Maharashtra (p=0·008) states; this association was not significant in Tamil Nadu (p=0·06), Manipur (p=0·62), and Nagaland (p=0·67). Overall, we estimated that 100,178 HIV infections (95% CI 25,897-207,713) were averted at the population level from 2003 up to 2008 as a result of Avahan.

INTERPRETATION

The results of our analysis suggest that Avahan had a beneficial effect in reducing HIV prevalence at the population level over 5 years of programme implementation in some of the states. With stagnating funding for HIV prevention globally, our findings support investment in well planned and managed HIV prevention programmes in low-income and middle-income countries.

FUNDING

Bill & Melinda Gates Foundation.

Decision making for HIV prevention and treatment scale up: bridging the gap between theory and practice

BACKGROUND

Effectively controlling the HIV epidemic will require efficient use of limited resources. Despite ambitious global goals for HIV prevention and treatment scale up, few comprehensive practical tools exist to inform such decisions.

METHODS

We briefly summarize modeling approaches for resource allocation for epidemic control, and discuss the practical limitations of these models. We describe typical challenges of HIV resource allocation in practice and some of the tools used by decision makers. We identify the characteristics needed in a model that can effectively support planners in decision making about HIV prevention and treatment scale up.

RESULTS

An effective model to support HIV scale-up decisions will be flexible, with capability for parameter customization and incorporation of uncertainty. Such a model needs certain key technical features: it must capture epidemic effects; account for how intervention effectiveness depends on the target population and the level of scale up; capture benefit and cost differentials for packages of interventions versus single interventions, including both treatment and prevention interventions; incorporate key constraints on potential funding allocations; identify optimal or near-optimal solutions; and estimate the impact of HIV interventions on the health care system and the resulting resource needs. Additionally, an effective model needs a user-friendly design and structure, ease of calibration and validation, and accessibility to decision makers in all settings.

CONCLUSIONS

Resource allocation theory can make a significant contribution to decision making about HIV prevention and treatment scale up. What remains now is to develop models that can bridge the gap between theory and practice.

Young and vulnerable: spatial-temporal trends and risk factors for infant mortality in rural South Africa (Agincourt), 1992-2007

BACKGROUND

Infant mortality is an important indicator of population health in a country. It is associated with several health determinants, such as maternal health, access to high-quality health care, socioeconomic conditions, and public health policy and practices.

METHODS

A spatial-temporal analysis was performed to assess changes in infant mortality patterns between 1992-2007 and to identify factors associated with infant mortality risk in the Agincourt sub-district, rural northeast South Africa. Period, sex, refugee status, maternal and fertility-related factors, household mortality experience, distance to nearest primary health care facility, and socio-economic status were examined as possible risk factors. All-cause and cause-specific mortality maps were developed to identify high risk areas within the study site. The analysis was carried out by fitting Bayesian hierarchical geostatistical negative binomial autoregressive models using Markov chain Monte Carlo simulation. Simulation-based Bayesian kriging was used to produce maps of all-cause and cause-specific mortality risk.

RESULTS

Infant mortality increased significantly over the study period, largely due to the impact of the HIV epidemic. There was a high burden of neonatal mortality (especially perinatal) with several hot spots observed in close proximity to health facilities. Significant risk factors for all-cause infant mortality were mother's death in first year (most commonly due to HIV), death of previous sibling and increasing number of household deaths. Being born to a Mozambican mother posed a significant risk for infectious and parasitic deaths, particularly acute diarrhoea and malnutrition.

CONCLUSIONS

This study demonstrates the use of Bayesian geostatistical models in assessing risk factors and producing smooth maps of infant mortality risk in a health and socio-demographic surveillance system. Results showed marked geographical differences in mortality risk across a relatively small area. Prevention of vertical transmission of HIV and survival of mothers during the infants' first year in high prevalence villages needs to be urgently addressed, including expanded antenatal testing, prevention of mother-to-child transmission, and improved access to antiretroviral therapy. There is also need to assess and improve the capacity of district hospitals for emergency obstetric and newborn care. Persisting risk factors, including inadequate provision of clean water and sanitation, are yet to be fully addressed.

Postexposure prophylaxis, preexposure prophylaxis or universal test and treat: the strategic use of antiretroviral drugs to prevent HIV acquisition and transmission

This review considers the use of antiretroviral drugs specifically to prevent HIV transmission. Antiretroviral therapy (ART) can be implemented for the protection of uninfected individuals both before (preexposure prophylaxis) and after (postexposure prophylaxis) exposure to HIV infection. Preexposure prophylaxis may be used coitally dependently when individuals are intermittently exposed or by continuous daily dosing for those constantly exposed; postexposure prophylaxis is used in 28-day courses. Alternatively, ART can be used strategically to reduce the viral load and consequent infectiousness of an HIV-infected individual, thereby limiting the risk of onward viral transmission. A policy of universal HIV testing to enhance the identification of all HIV-positive individuals followed by immediate treatment of all HIV-positive individuals, irrespective of their CD4 cell counts (universal test and treat), has been postulated as a potential tool capable of reducing HIV incidence at a population level. This concept represents a paradigm shift in the use of ART, targeting infectious individuals for prevention rather than protecting uninfected exposed populations. This strategy could have the advantage of preventing transmission and reducing HIV incidence at a population level, as well as delivering universal access to therapy for all people living with HIV and AIDS, potentially eliminating mother-to-child HIV transmission and limiting concomitant diseases such as tuberculosis. This review critically examines the scientific basis of ART for HIV prevention, summarizing the risks and opportunities of the potential expansion of ART for prevention. Specifically, we consider the evidences for and against targeting HIV-uninfected individuals compared with enhanced HIV testing and treatment of HIV-infected individuals in terms of impact on viral transmission.

Rethinking prevention of HIV type 1 infection

Research on the prevention of human immunodeficiency virus (HIV)-1 infection is at a critical juncture. Major methodological challenges to performing prevention trials have emerged, and one after another promising biomedical interventions have failed to reduce the incidence of HIV-1 infection. Nevertheless, there is growing optimism that progress can be achieved in the near term. Mathematical modeling indicates that 2 new strategies, "test and treat" and preexposure prophylaxis, could have a major impact on the incidence of HIV-1 infection. Will our hopes be justified? We review the potential strengths and limitations of these antiretroviral "treatment as prevention" strategies and outline other new options for reducing the incidence of HIV-1 infection in the near term. By maximizing the potential of existing interventions, developing other effective strategies, and combining them in an optimal manner, we have the opportunity to bring the HIV-1 epidemic under control.

Determining a cost effective intervention response to HIV/AIDS in Peru

BACKGROUND

The HIV epidemic in Peru is still regarded as concentrated -- sentinel surveillance data shows greatest rates of infection in men who have sex with men, while much lower rates are found in female sex workers and still lower in the general population. Without an appropriate set of preventive interventions, continuing infections could present a challenge to the sustainability of the present programme of universal access to treatment. Determining how specific prevention and care strategies would impact on the health of Peruvians should be key in reshaping the national response.

METHODS

HIV/AIDS prevalence levels for risk groups with sufficient sentinel survey data were estimated. Unit costs were calculated for a series of interventions against HIV/AIDS which were subsequently inputted into a model to assess their ability to reduce infection transmission rates. Interventions included: mass media, voluntary counselling and testing; peer counselling for female sex workers; peer counselling for men who have sex with men; peer education of youth in-school; condom provision; STI treatment; prevention of mother to child transmission; and highly active antiretroviral therapy. Impact was assessed by the ability to reduce rates of transmission and quantified in terms of cost per DALY averted.

RESULTS

Results of the analysis show that in Peru, the highest levels of HIV prevalence are found in men who have sex with men. Cost effectiveness varied greatly between interventions ranging from peer education of female commercial sex workers at $US 55 up to $US 5,928 (per DALY averted) for prevention of mother to child transmission.

CONCLUSION

The results of this work add evidence-based clarity as to which interventions warrant greatest consideration when planning an intervention response to HIV in Peru. Cost effectiveness analysis provides a necessary element of transparency when facing choices about priority setting, particularly when the country plans to amplify its response through new interventions partly funded by the GFATM.

Complexity, cofactors, and the failure of AIDS policy in Africa

Global AIDS policy still treats HIV as an exceptional case, abstracting from the context in which infection occurs. Policy is based on a simplistic theory of HIV causation, and evaluated using outdated tools of health economics. Recent calls for a health systems strategy – preventing and treating HIV within a programme of comprehensive health care – have not yet influenced the silo approach of AIDS policy.

Evidence continues to accumulate, showing that multiple factors, such as malnutrition, malaria and helminthes, increase the risk of sexual and vertical transmission of HIV. Moreover, complementary interventions that reduce viral load, improve immune response, and interrupt pathways of transmission could increase the effectiveness of antiretroviral drugs and other tools of AIDS policy.

In health economics, the omission of estimates of increasing returns generated by disease or treatment synergies biases cost-effectiveness analysis against multiple, yet inexpensive, interventions. Current tools of cost-effectiveness analysis only identify local maxima in a complex landscape, and can play, at best, a marginal role in the epidemic, especially where it is already generalized.

Cost-effectiveness analyses for HIV that are based on the wrong epidemiological model can generate Type III errors: we get precise answers to the wrong questions about how to intervene. To control the epidemic, AIDS policy needs to utilize an epidemiological model that reflects the interactions of biological as well as behavioural variables that determine the course of HIV epidemics around the world. Cost-effectiveness analysis can benefit from using economic concepts of externalities and increasing returns to incorporate disease interactions and beneficial treatment spillovers for coinfections in HIV-prevention policy.

The role of testing and counselling for HIV prevention and care in the era of scaling-up antiretroviral therapy

OBJECTIVE

HIV Testing and Counselling (TC) programmes are being scaled-up as part of efforts to provide universal access to antiretroviral treatment (ART).

METHODS AND FINDINGS

Mathematical modelling of TC in Zimbabwe shows that if universal access is to be sustained, TC must include prevention counselling that enables behaviour change among infected and uninfected individuals. The predicted impact TC is modest, but improved programmes could generate substantial reductions in incidence, reducing need for ART in the long-term.

CONCLUSIONS

TC programmes that focus only on identifying those in need of treatment will not be sufficient to bring the epidemic under control.

Evaluation design for large-scale HIV prevention programmes: the case of Avahan, the India AIDS initiative

BACKGROUND

Closing the HIV prevention gap to prevent HIV infections requires rapid, worldwide rollout of large-scale national programmes. Evaluating such programmes is challenging and complex, requiring clarity of evaluation purpose and evidential approaches substantively different to those employed for pilots and small programmes.

OBJECTIVES

This paper describes the evaluation design for the implementation phase of Avahan, the India AIDS initiative, a large HIV prevention programme funded by the Bill and Melinda Gates Foundation. Avahan, which began in December 2003, has a 10-year charter to impact the Indian epidemic and its response by implementing an HIV prevention programme targeting core and bridge groups in 83 districts of six Indian states, transferring the programme to the Government of India, and disseminating programme learning.

METHODS

The foundation commissioned an external process to design Avahan's evaluation framework. An independent advisory group oversees and guides course corrections in the execution of this framework.

RESULTS

Avahan's evaluation framework comprises: trend and synthetic analysis of data from core, bridge and household biobehavioural surveys in a subset of intervention districts, denominator estimates and programme monitoring from all intervention districts, and government's antenatal surveillance (two sites per district in all districts); bespoke transmission dynamics modelling to estimate infections averted (subset of districts); cost effectiveness studies (subset of districts). In addition, there are other knowledge-building and quality-monitoring activities.

CONCLUSION

Rather than a small set of monofocal outcome measures, scaled programmes require nuanced evaluations that approximate programmatic scale by collecting data with different levels of geographical scope, synthesize multiple data and methods to arrive at a composite picture, and can cope with continuous environmental and programme evolution.

Cost-effectiveness of HIV monitoring strategies in resource-limited settings: a southern African analysis

BACKGROUND

Although the number of infected persons receiving highly active antiretroviral therapy (HAART) in low- and middle-income countries has increased dramatically, optimal disease management is not well defined.

METHODS

We developed a model to compare the costs and benefits of 3 types of human immunodeficiency virus monitoring strategies: symptom-based strategies, CD4-based strategies, and CD4 counts plus viral load strategies for starting, switching, and stopping HAART. We used clinical and cost data from southern Africa and performed a cost-effectiveness analysis. All assumptions were tested in sensitivity analyses.

RESULTS

Compared with the symptom-based approaches, monitoring CD4 counts every 6 months and starting treatment at a threshold of 200/muL was associated with a gain in life expectancy of 6.5 months (61.9 months vs 68.4 months) and a discounted lifetime cost savings of US $464 per person (US $4069 vs US $3605, discounted 2007 dollars). The CD4-based strategies in which treatment was started at the higher threshold of 350/microL provided an additional gain in life expectancy of 5.3 months at a cost-effectiveness of US $107 per life-year gained compared with a threshold of 200/microL. Monitoring viral load with CD4 was more expensive than monitoring CD4 counts alone, added 2.0 months of life, and had an incremental cost-effectiveness ratio of US $5414 per life-year gained relative to monitoring of CD4 counts. In sensitivity analyses, the cost savings from CD4 count monitoring compared with the symptom-based approaches was sensitive to cost of inpatient care, and the cost-effectiveness of viral load monitoring was influenced by the per test costs and rates of virologic failure.

CONCLUSIONS

Use of CD4 monitoring and early initiation of HAART in southern Africa provides large health benefits relative to symptom-based approaches for HAART management. In southern African countries with relatively high costs of hospitalization, CD4 monitoring would likely reduce total health care expenditures. The cost-effectiveness of viral load monitoring depends on test prices and rates of virologic failure.

Estimating the number of HIV infections averted: an approach and its issues

Objective:

To propose a methodology to estimate the number of new HIV infections averted. Knowledge of HIV infection has increased tremendously and modelling tools to project current epidemics into the future have greatly improved. Different types of models can be used to estimate HIV infections averted, although the number of new HIV infections averted cannot be measured directly.

Method:

Using cohort-component population projections, a disease modelling-based approach was used to compare the observed epidemiology of a disease after programme initiation with an expected epidemiology from past trends before programme initiation. The concept of modelling infections averted in a disease modelling-based approach involves a comparison between an “expected” or baseline epidemic with an “estimated” one. A hypothetical example was featured in order to demonstrate the proposed methodology. Using both the Estimation and Projection Package (EPP) and the Spectrum demographic modelling program, the underlying annual incidence levels implied by both the baseline and estimated epidemics were examined.

Results:

The difference between baseline and estimated incidence levels is interpreted as “infections averted”. Strengths and limitations of the approach are discussed.

Conclusions:

In this study an expected epidemiological approach was compared to one based on observation. Once sufficient data become available, the validation of various country data including HIV prevalence, mortality, and behaviour must be done. Additional information related to behaviour change may be critical to further support arguments for a change in disease trend. It is therefore important to use all available data, consequently strengthening findings from a disease modelling-based approach on HIV infections averted.

Understanding the impact of male circumcision interventions on the spread of HIV in southern Africa

Background

Three randomised controlled trials have clearly shown that circumcision of adult men reduces the chance that they acquire HIV infection. However, the potential impact of circumcision programmes – either alone or in combination with other established approaches – is not known and no further field trials are planned. We have used a mathematical model, parameterised using existing trial findings, to understand and predict the impact of circumcision programmes at the population level.

Findings

Our results indicate that circumcision will lead to reductions in incidence for women and uncircumcised men, as well as those circumcised, but that even the most effective intervention is unlikely to completely stem the spread of the virus. Without additional interventions, HIV incidence could eventually be reduced by 25–35%, depending on the level of coverage achieved and whether onward transmission from circumcised men is also reduced. However, circumcision interventions can act synergistically with other types of prevention programmes, and if efforts to change behaviour are increased in parallel with the scale-up of circumcision services, then dramatic reductions in HIV incidence could be achieved. In the long-term, this could lead to reduced AIDS deaths and less need for anti-retroviral therapy. Any increases in risk behaviours following circumcision , i.e. ‘risk compensation’, could offset some of the potential benefit of the intervention, especially for women, but only very large increases would lead to more infections overall.

Conclusions

Circumcision will not be the silver bullet to prevent HIV transmission, but interventions could help to substantially protect men and women from infection, especially in combination with other approaches.

"Bundling" HIV prevention: integrating services to promote synergistic gain

BACKGROUND

Bundling is defined as the aggregation of services to increase effectiveness (i.e., creating synergy of effort). The purpose of this commentary is to review the utilization and potential benefits of bundling in its application to HIV prevention.

METHODS

Review of the literature to provide a broad perspective on the concept of bundling and specific examples of bundling in HIV prevention. Benefits, challenges and directions are considered.

RESULTS

To be effective, bundling must offer strategic advantage: greater value, less cost. It provides an opportunity to target multiple risk behaviors simultaneously for synergistic gain. Technological advances including rapid HIV tests permit noninvasive sampling in clinical and non-clinical settings. Bundling of HIV prevention provides an opportunity to reach high-risk persons who are asymptomatic and/or may not otherwise seek care by eliminating barriers to prevention.

CONCLUSIONS

We must implement programs that work and consider innovative approaches to stem the AIDS epidemic; bundling provides one such opportunity to create an efficient paradigm targeting multiple risk behaviors simultaneously.

Factors Influencing Condom Use among Sexually Transmitted Infection Clinic Patients in Montego Bay, Jamaica

The use of condoms can reduce the risk of sexually transmitted infections (STIs) including the human immunodeficiency virus (HIV) infection. We conducted this study to determine factors that impact condom use among patients attending an STI clinic in Montego Bay, Jamaica. A questionnaire containing sections on socio-demographic characteristics, knowledge of STIs and HIV, preventive measures for STI/HIV transmission and sexual practices including condom use was administered to 212 participants. Using logistic regression, we determined the relationship between the different factors and condom use during the last sexual episode. Approximately 43% of study participants reported condom use during the last sexual episode. Employment (OR=2.2; 95%CI=1.1-4.1) and greater knowledge of STIs (OR=1.9, 95%CI=1.02-3.6) were associated with increased likelihood of condom use during the last sexual episode. Having multiple sexual partners was associated with decreased likelihood to report condom use (OR=0.3, 95%CI=0.1-0.9). Also, persons belonging to a religious organization were less likely to report condom use (OR=0.5, 95%CI=0.2-0.9). The results of this study can be used in formulating effective strategies to increase condom use in Montego Bay. This would decrease the transmission of STIs and HIV.

Global Fund-supported programmes contribution to international targets and the Millennium Development Goals: an initial analysis

OBJECTIVE

The Global Fund to Fight AIDS, Tuberculosis and Malaria is one of the largest funders to fight these diseases. This paper discusses the programmatic contribution of Global Fund-supported programmes towards achieving international targets and Millennium Development Goals, using data from Global Fund grants.

METHODOLOGY

Results until June 2006 of 333 grants supported by the Global Fund in 127 countries were aggregated and compared against international targets for HIV/AIDS, tuberculosis and malaria. Progress reports to the Global Fund secretariat were used as a basis to calculate results. Service delivery indicators for antiretrovirals (ARV) for HIV/AIDS, case detection under the DOTS strategy for tuberculosis (DOTS) and insecticide-treated nets (ITNs) for malaria prevention were selected to estimate programmatic contributions to international targets for the three diseases. Targets of Global Fund-supported programmes were projected based on proposals for Rounds 1 to 4 and compared to international targets for 2009.

FINDINGS

Results for Global Fund-supported programmes total 544,000 people on ARV, 1.4 million on DOTS and 11.3 million for ITNs by June 2006. Global Fund-supported programmes contributed 18% of international ARV targets, 29% of DOTS targets and 9% of ITNs in sub-Saharan Africa by mid-2006. Existing Global Fund-supported programmes have agreed targets that are projected to account for 19% of the international target for ARV delivery expected for 2009, 28% of the international target for DOTS and 84% of ITN targets in sub-Saharan Africa.

CONCLUSION

Global Fund-supported programmes have already contributed substantially to international targets by mid-2006, but there is a still significant gap. Considerably greater financial support is needed, particularly for HIV, in order to achieve international targets for 2009.

An assessment of sites where persons go to meet sexual partners in St. James, Jamaica, using the PLACE method

OBJECTIVE

The objective of this study was to assess sexual behavior of persons at risk of HIV infection.

GOAL

The goal of this study was to identify sites where HIV prevention is needed.

STUDY DESIGN

Customers at sites where persons meet new sex partners in St. James, Jamaica, were surveyed.

RESULTS

Of 421 sites, 282 men and 200 women (random sample, 23 sites) and 320 men and 265 women (special sample, 26 sites) were interviewed. Over one fourth of men and 14% (special) and 4% (random) of women had one or more new sex partners in the last 4 weeks. Seventy-eight percent of men reported condom use at last sex with a new partner compared with 66% of women. Approximately 50% of respondents reported condom use at last sex with a regular partner.

CONCLUSION

Sites at which people meet new sex partners were diverse with significant opportunities for prevention. Commercial and transactional sex are features at many sites.

Human immunodeficiency virus (HIV) in developing countries

The human immunodeficiency virus (HIV) is causing the most destructive epidemic of recent times, having been responsible for the deaths of more than 25 million people since it was first recognised in 1981. This global epidemic remains out of control, with reported figures for 2005 of 40 million people infected with HIV. During 2005 there were 4.9 million new infections, showing that transmission is not being prevented, and there were 3.1 million deaths from the acquired immunodeficiency syndrome (AIDS), reflecting the lack of a definitive cure and the limited access to suppressive antiretroviral treatment in the developing countries that are most severely affected. The current state of the epidemic and the response to date are here reviewed. Present and future opportunities for prevention, treatment and surveillance are discussed, with particular reference to progress towards an HIV vaccine, the expansion of the provision of highly active antiretroviral therapy, and the need to focus control programmes on HIV as an infectious disease, rather than as a development issue.

The global epidemiology of HIV/AIDS

HIV infected nearly 5 million and killed more than 3 million people in 2005. Whereas traditional epidemics have been limited to high-risk populations, in many regions, it has generalized to the at-large population, with heterosexual sex being the predominant source of transmission. The virus has hit sub-Saharan Africa the hardest, although major epidemics are now transpiring in Asia, Eastern Europe, and the Caribbean. The United Nations and World Health Organization have produced targeted prevention strategies to control the pandemic that focus on comprehensive prevention activities and universal access to care.

Multicenter evaluation of the Bayer ADVIA Centaur HIV 1/O/2 enhanced (EHIV) assay

BACKGROUND

It is important that serological assays detect antibodies to human immunodeficiency virus (HIV) in all infected individuals, including those infected with less prevalent, more diverse subtypes.

METHODS

Performance of the ADVIA Centaur HIV 1/O/2 Enhanced (EHIV) Assay was tested on 1344 samples from HIV-positive subjects, 6061 samples from groups at low-risk for HIV infection, and 1042 samples from groups at high-risk for HIV-1 and HIV-2 infection. Results were compared with those of an FDA-approved predicate assay.

RESULTS

The ADVIA Centaur EHIV Assay showed good precision with a diagnostic specificity of 99.9% and diagnostic sensitivity of 100%. HIV seroconversion was detected earlier in 6 panels, at the same time in 13 panels and later in only 1 of the panels when compared to the predicate assay, thereby narrowing the window period between infection and antibody detection. Of clinical significance, a blood donor sample that was indeterminate by HIV-1 Western blot and non-reactive by the predicate assay was repeatedly reactive in the ADVIA Centaur Assay and confirmed as positive by HIV-2 immunoblot.

CONCLUSIONS

The ADVIA Centaur EHIV Assay is useful as an aid in the diagnosis of individuals infected with HIV-1 and/or HIV-2.

Projections of global mortality and burden of disease from 2002 to 2030

BACKGROUND

Global and regional projections of mortality and burden of disease by cause for the years 2000, 2010, and 2030 were published by Murray and Lopez in 1996 as part of the Global Burden of Disease project. These projections, which are based on 1990 data, continue to be widely quoted, although they are substantially outdated; in particular, they substantially underestimated the spread of HIV/AIDS. To address the widespread demand for information on likely future trends in global health, and thereby to support international health policy and priority setting, we have prepared new projections of mortality and burden of disease to 2030 starting from World Health Organization estimates of mortality and burden of disease for 2002. This paper describes the methods, assumptions, input data, and results.

METHODS AND FINDINGS

Relatively simple models were used to project future health trends under three scenarios-baseline, optimistic, and pessimistic-based largely on projections of economic and social development, and using the historically observed relationships of these with cause-specific mortality rates. Data inputs have been updated to take account of the greater availability of death registration data and the latest available projections for HIV/AIDS, income, human capital, tobacco smoking, body mass index, and other inputs. In all three scenarios there is a dramatic shift in the distribution of deaths from younger to older ages and from communicable, maternal, perinatal, and nutritional causes to noncommunicable disease causes. The risk of death for children younger than 5 y is projected to fall by nearly 50% in the baseline scenario between 2002 and 2030. The proportion of deaths due to noncommunicable disease is projected to rise from 59% in 2002 to 69% in 2030. Global HIV/AIDS deaths are projected to rise from 2.8 million in 2002 to 6.5 million in 2030 under the baseline scenario, which assumes coverage with antiretroviral drugs reaches 80% by 2012. Under the optimistic scenario, which also assumes increased prevention activity, HIV/AIDS deaths are projected to drop to 3.7 million in 2030. Total tobacco-attributable deaths are projected to rise from 5.4 million in 2005 to 6.4 million in 2015 and 8.3 million in 2030 under our baseline scenario. Tobacco is projected to kill 50% more people in 2015 than HIV/AIDS, and to be responsible for 10% of all deaths globally. The three leading causes of burden of disease in 2030 are projected to include HIV/AIDS, unipolar depressive disorders, and ischaemic heart disease in the baseline and pessimistic scenarios. Road traffic accidents are the fourth leading cause in the baseline scenario, and the third leading cause ahead of ischaemic heart disease in the optimistic scenario. Under the baseline scenario, HIV/AIDS becomes the leading cause of burden of disease in middle- and low-income countries by 2015.

CONCLUSIONS

These projections represent a set of three visions of the future for population health, based on certain explicit assumptions. Despite the wide uncertainty ranges around future projections, they enable us to appreciate better the implications for health and health policy of currently observed trends, and the likely impact of fairly certain future trends, such as the ageing of the population, the continued spread of HIV/AIDS in many regions, and the continuation of the epidemiological transition in developing countries. The results depend strongly on the assumption that future mortality trends in poor countries will have a relationship to economic and social development similar to those that have occurred in the higher-income countries.

From trial intervention to scale-up: costs of an adolescent sexual health program in Mwanza, Tanzania

OBJECTIVE

To estimate annual costs of a multifaceted adolescent sexual health intervention in Mwanza, Tanzania, by input (capital and recurrent), component (in-school, community activities, youth-friendly health services, condom distribution), and phase (development, startup, trial implementation, scale-up).

STUDY DESIGN

Financial and economic providers' costs and intervention outputs were collected to estimate annual total and unit costs (1999-2001). The incremental financial budget projects funding requirements for scale-up within an integrated model.

RESULTS

The 3-year economic costs of trial implementation were US dollars 879,032, of which approximately 70% were for the school-based component. Costs of initial development and startup were relatively substantial ( approximately 21% of total costs); however, annual costs per school child dropped from US dollars 16 in 1999 to US dollars 10 in 2001. The incremental scale-up cost is approximately 1/5 of ward trial implementation running costs.

CONCLUSIONS

Annual costs can reduce by almost 40% as project implementation matures. When scaled up, only an additional US dollars 1.54 is needed per pupil per year to continue the intervention.

Head-to-head comparison on the immunogenicity of two HIV/AIDS vaccine candidates based on the attenuated poxvirus strains MVA and NYVAC co-expressing in a single locus the HIV-1BX08 gp120 and HIV-1(IIIB) Gag-Pol-Nef proteins of clade B

In this investigation we have generated and defined the immunogenicity of two novel HIV/AIDS vaccine candidates based on the highly attenuated vaccinia virus strains, MVA and NYVAC, efficiently expressing in the same locus (TK) and under the same viral promoter the codon optimized HIV-1 genes encoding gp120 and Gag-Pol-Nef antigens of clade B (referred as MVA-B and NYVAC-B). In infected human HeLa cells, gp120 is released from cells and GPN is produced as a polyprotein; NYVAC-B induces severe apoptosis but not MVA-B. The two poxvirus vectors showed genetic stability of the inserts. In BALB/c and in transgenic HHD mice for human HLA-A2 class I, both vectors are efficient immunogens and induced broad cellular immune responses against peptides represented in the four HIV-1 antigens. Some differences were observed in the magnitude and breadth of the immune response in the mouse models. In DNA prime/poxvirus boost protocols, the strongest immune response, as measured by fresh IFN-gamma and IL-2 ELISPOT, was obtained in BALB/c mice boosted with NYVAC-B, while in HHD mice there were no differences between the poxvirus vectors. When the prime/boost was performed with homologous or with combination of poxvirus vectors, the protocols MVA-B/MVA-B and NYVAC-B/NYVAC-B, or the combination NYVAC-B/MVA-B gave the most consistent broader immune response in both mouse models, although the magnitude of the overall response was higher for the DNA-B/poxvirus-B regime. All of the immunization protocols induced some humoral response against the gp160 protein from HIV-1 clone LAV. Our findings indicate that MVA-B and NYVAC-B meet the criteria to be potentially useful vaccine candidates against HIV/AIDS.

Dynamic model of HIV/AIDS population of Agra region

The Human Immunodeficiency Virus / Acquired Immunodeficiency syndrome (HIV/AIDS) is spreading rapidly in all regions of the world. But in India it is only 20 years old. Within this short period it has emerged as one of the most serious public health problems in the country, which greatly affect the socio-economical growth. The HIV problem is very complex and ill defined from the modeling point of view. Keeping in the view the complexities of the HIV infection and its transmission, it is difficult to make exact estimates of HIV prevalence. It is more so in the Indian context, with its typical and varied cultural characteristics, and its traditions and values with special reference to sex related risk behaviors. Therefore, it is necessary to develop a good model which will help in making exact estimates of HIV prevalence that may be used for planning HIV / AIDS prevention and control programs. In this paper Neuro-Fuzzy approach has been used to develop dynamic model of HIV population of Agra region.