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John Stover

Publications and source records attributed to John Stover.

13 recordsLinked to original sources
PubMed2006

Monitoring the scale-up of antiretroviral therapy programmes: methods to estimate coverage.

This paper reviews the data sources and methods used to estimate the number of people on, and coverage of, antiretroviral therapy (ART) programmes in low- and middle-income countries and to monitor the progress towards the "3 by 5" target set by WHO and UNAIDS. We include a review of the data sources used to estimate the coverage of ART programmes as well as the efforts made to avoid double counting and over-reporting. The methods used to estimate the number of people in need of ART are described and expanded with estimates of treatment needs for children, both for ART and for cotrimoxazole prophylaxis. An estimated 6.5 million people were in need of treatment in low- and middle-income countries by the end of 2004, including 660,000 children under age 15 years. The mid-2005 estimate of 970,000 people receiving ART in low- and middle-income countries (with an uncertainty range 840,000-1,100,000) corresponds to a coverage of 15% of people in need of treatment.

Adolescent↗
PubMed2006

The global impact of scaling up HIV/AIDS prevention programs in low- and middle-income countries.

A strong, global commitment to expanded prevention programs targeted at sexual transmission and transmission among injecting drug users, started now, could avert 28 million new HIV infections between 2005 and 2015. This figure is more than half of the new infections that might otherwise occur during that period in 125 low- and middle-income countries. Although preventing these new infections would require investing about U.S.$122 billion over this period, it would reduce future needs for treatment and care. Our analysis suggests that it will cost about U.S.$3900 to prevent each new infection, but that this will produce a savings of U.S.$4700 in forgone treatment and care costs. Thus, greater spending on prevention now would not only prevent more than half the new infections that would occur from 2005 to 2015 but would actually produce a net financial saving as future costs for treatment and care are averted.

Acquired Immunodeficiency Syndrome↗
PubMed2005

Integrating HIV prevention and treatment: from slogans to impact.

BACKGROUND: Through major efforts to reduce costs and expand access to antiretroviral therapy worldwide, widespread delivery of effective treatment to people living with HIV/AIDS is now conceivable even in severely resource-constrained settings. However, the potential epidemiologic impact of treatment in the context of a broader strategy for HIV/AIDS control has not yet been examined. In this paper, we quantify the opportunities and potential risks of large-scale treatment roll-out. METHODS AND FINDINGS: We used an epidemiologic model of HIV/AIDS, calibrated to sub-Saharan Africa, to investigate a range of possible positive and negative health outcomes under alternative scenarios that reflect varying implementation of prevention and treatment. In baseline projections, reflecting "business as usual," the numbers of new infections and AIDS deaths are expected to continue rising. In two scenarios representing treatment-centered strategies, with different assumptions about the impact of treatment on transmissibility and behavior, the change in the total number of new infections through 2020 ranges from a 10% increase to a 6% reduction, while the number of AIDS deaths through 2020 declines by 9% to 13%. A prevention-centered strategy provides greater reductions in incidence (36%) and mortality reductions similar to those of the treatment-centered scenarios by 2020, but more modest mortality benefits over the next 5 to 10 years. If treatment enhances prevention in a combined response, the expected benefits are substantial-29 million averted infections (55%) and 10 million averted deaths (27%) through the year 2020. However, if a narrow focus on treatment scale-up leads to reduced effectiveness of prevention efforts, the benefits of a combined response are considerably smaller-9 million averted infections (17%) and 6 million averted deaths (16%). Combining treatment with effective prevention efforts could reduce the resource needs for treatment dramatically in the long term. In the various scenarios the numbers of people being treated in 2020 ranges from 9.2 million in a treatment-only scenario with mixed effects, to 4.2 million in a combined response scenario with positive treatment-prevention synergies. CONCLUSIONS: These analyses demonstrate the importance of integrating expanded care activities with prevention activities if there are to be long-term reductions in the number of new HIV infections and significant declines in AIDS mortality. Treatment can enable more effective prevention, and prevention makes treatment affordable. Sustained progress in the global fight against HIV/AIDS will be attained only through a comprehensive response.

Africa↗
PubMed2005

Thiopental-induced apoptosis in lymphocytes is independent of CD95 activation.

BACKGROUND: Barbiturate coma is used in patients with traumatic brain injury whenever increases in intracranial pressure remain unresponsive to less aggressive therapeutic regimens. However, barbiturate-mediated neuroprotection correlates with lymphopenia, which increases the risk of infection. The mechanisms by which barbiturates lead to lymphopenia remain to be determined. METHODS: Freshly isolated human lymphocytes and Jurkat cells were incubated with the barbiturate thiopental for 24 and 48 h. Apoptosis was measured by fluorescein isothiocyanate-Annexin and propidium iodide staining, rhodamine 123 staining, and the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method. Caspase-3 activity was detected by Western blot and substrate cleavage assay. RESULTS: Thiopental dose-dependently (5-500 microg/ml) increased apoptosis in Jurkat cells from basal levels (4.4 +/- 1.9%) to 29.7 +/- 2.8% after 24 h and 39.7 +/- 3.2% after 48 h, whereas in lymphocytes, thiopental-induced necrosis was observed. Parallel to apoptosis, thiopental dose-dependently increased caspase-3-like activity in Jurkat cells. However, the pan-caspase inhibitor z-VAD-fmk (20 microm) only marginally reduced thiopental-induced (250 microg/ml) apoptosis in Jurkat cells (20.2 +/- 2.5 to 17.2 +/- 2.5%) and necrosis in lymphocytes (39.2 +/- 7.5 to 30.7 +/- 14%). In contrast, anti-CD95-induced apoptosis in Jurkat cells (27.0 +/- 2.0%) was completely blocked by z-VAD-fmk (8.1 +/- 1.8%). Neither expression of CD95 on Jurkat cells nor pretreatment with a neutralizing anti-CD95 antibody influenced thiopental-induced apoptosis, indicating that thiopental induces apoptosis independently of the CD95 system. The nuclear factor kappaB inhibitor gliotoxin accelerated both thiopental- and CD95-mediated apoptosis, indicating a mutual control mechanism of thiopental- and CD95-induced apoptosis. CONCLUSIONS: Thiopental directly induces cell death in lymphocytes and Jurkat cells by a CD95-independent mechanism.

Apoptosis↗
PubMed2005

Using HIV surveillance data: recent experiences and avenues for the future.

HIV surveillance systems provide information that is crucial to our understanding of epidemic dynamics among different populations in different settings. Surveillance data are also used for advocacy, to inform policies and programming, and for monitoring. Multiple data sources may be used and will expand in the future as service statistics from prevention and treatment programmes become available. Important and new priorities in HIV surveillance data use at the national and local levels can build on past experience with surveillance reports, national estimates, advocacy materials, and communications to the media. A new framework, integrated analysis of data from expanded surveillance systems and other sources, is proposed to inform improved programming. The approach allows making effective programme choices, based on the analysis of biological and behavioral data and the coverage of interventions in an integrated fashion. The comparison of surveillance data with financial data provides added insights in the adequacy of the response. These findings and experiences set a new agenda for technical and structural directions to improve data use in countries.

Communication↗
PubMed2004

Testing the accuracy of demographic estimates in countries with generalized epidemics.

OBJECTIVE: To assess the accuracy of demographic estimates that include the effects of HIV/AIDS on adult mortality. DESIGN: To compare estimates of demographic indicators based on UNAIDS/WHO estimates and projections with newly available estimates based on cohort studies, hospital records, national surveys and other sources of data. METHODS: New information has become available recently from a number of sites in Africa on the ratio of mortality among the HIV-positive and HIV-negative population, the proportion of all adult deaths attributable to AIDS, and the number of orphans. These data are compared with the same indicators calculated from UNAIDS/WHO estimates to assess the accuracy of those estimates. RESULTS: Differences between demographic indicators based on UNAIDS/WHO estimates and study-based estimates are generally within the uncertainty range of the UNAIDS/WHO figures. CONCLUSION: Demographic estimates based on surveillance data and demographic models are close enough to study-based estimates to be useful for advocacy and medium-term planning. However, significant differences do exist that should be taken into account for short-term planning.

Acquired Immunodeficiency Syndrome↗
PubMed2004

Where are the gaps? The effects of HIV-prevention interventions on behavioral change.

As more funding becomes available for HIV/AIDS programs in developing countries, an understanding of how prevention interventions lead to behavioral change and how behavioral change leads to reductions in HIV prevalence is crucial. This study presents the results of an extensive effort to develop a matrix to relate coverage of key HIV/AIDS-prevention services to changes in behavior among different risk groups and to describe the gaps that exist in the literature. Many studies could not be included in the matrix because they did not meet the necessary criteria. Evaluation of interventions targeting abstinence programs, workplace programs, and certain groups at high risk of infection would prove invaluable.

Condoms↗
PubMed2003

Methods and procedures for estimating HIV/AIDS and its impact: the UNAIDS/WHO estimates for the end of 2001.

BACKGROUND: The Joint United Nations Programme on HIV and AIDS (UNAIDS) and the World Health Organization (WHO) have produced country-specific estimates of HIV/AIDS biannually since 1997. These estimates are a primary source of information about the extent and spread of the HIV/AIDS epidemic and its impact. The importance of having comparable country-specific estimates of HIV/AIDS is growing as estimates are used to determine how international resources to fight HIV/AIDS will be allocated to countries. OBJECTIVES: This paper describes the procedures and process used to make the 2001 round of UNAIDS/WHO estimates of HIV/AIDS. The paper focuses on the different approaches used to make estimates of prevalence in countries with generalized and low-level and concentrated epidemics as well as on new curve-fitting software that was developed to produce epidemic curves for each country. In addition, it presents the assumptions used (e.g. survival from infection to death, the rate of mother-to-child transmission) that are required to derive estimates of incidence and mortality in adults, as well as prevalence, incidence and mortality in children. CONCLUSION: The paper describes the general process by which the estimation and modelling procedures have been refined and improved over time. The paper also discusses the limitations and weaknesses of the procedures and the data used to make the estimates, and suggests areas where further improvements need to be made.

Acquired Immunodeficiency Syndrome↗
PubMed2002

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

HIV/AIDS has reached pandemic proportions, and is one of the leading causes of death worldwide. In 2001, the Declaration of Commitment on HIV/AIDS set out several aims with respect to reducing the effect and spread of HIV/AIDS, and an expanded response in low-income and middle-income countries was initiated. Here we examine the potential effect of the expanded global response based on analyses of epidemiological data, of mathematical models of HIV-1 transmission, and a review of the impact of prevention interventions on risk behaviours. Analyses suggest that if the successes achieved in some countries in prevention of transmission can be expanded to a global scale by 2005, about 29 million new infections could be prevented by 2010.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Resource requirements to fight HIV/AIDS in Latin America and the Caribbean.

OBJECTIVES: Economists and epidemiologists from 10 countries in Latin America and the Caribbean (LAC) reviewed the methods used to develop estimates for resource requirements to address HIV/AIDS prevention and care in low- and middle-income countries. METHODS: They applied their country-specific knowledge to re-estimate the costs, coverage, and capacity of their health and education systems to expand HIV/AIDS interventions by 2005. A discrepancy of 173 million US dollars exists between the model estimates and those of country specialists. RESULTS: The most important difference between the model estimates and those of country specialists was in the estimated future price of highly active antiretroviral therapy. To a large extent, the estimates of the model reflect the efficiency gains that could result from purchasing arrangements that lead LAC countries to lower prices for antiretroviral drugs. CONCLUSION: This preliminary exercise with 10 LAC countries confirmed the validity of the use of these estimates as tools at the international level, given current data limitations, both to guide the allocation of resources across diseases and countries, and for advocacy and resource mobilization. In addition, with the country revisions, these estimates have also been shown to be key tools for country-level strategic planning.

Acquired Immunodeficiency Syndrome↗