Four years of natural history of HIV-1 infection in African women : a prospective cohort study in Kigali (Rwanda), 1988-1993

Clinical features and mortality due to human immunodeficiency virus type-1 (HIV-1) infection in women are described as part of a prospective 4-year cohort study on perinatal transmission of HIV in Kigali, Rwanda. Two hundred fifteen HIV-positive (HIV+) and 216 HIV-negative (HIV-) pregnant women were enrolled at delivery between November 1988 and June 1989. Clinical information collected during systematic quarterly examinations was compared. HIV antibody tests were performed at delivery and CD4/CD8 lymphocyte counts at 15 days' postpartum. HIV- women who seroconverted during the follow-up period were excluded from the analysis of the comparison group starting at the date of seroconversion. At enrollment, all HIV+ women were asymptomatic for acquired immune deficiency syndrome (AIDS). Incidence of tuberculosis was 2.9 per 100 women-years (WY) after 4 years of follow-up in HIV+ women versus 0.2 per 100 WY among HIV- women (relative risk. 18.2% ; 95% confidence interval 2.4-137.0). Among HIV+ women, the incidence of AIDS was 3.5 per 100 WY. The mortality rate was 4.4 per 100 WY among HIV+ women versus 0.5 per 100 WY among HIV- women. Clinical AIDS was present in only half of the fatalities. Tuberculosis was a major cause of morbidity and mortality in these HIV+ African women. An early diagnosis and an appropriate treatment or prevention of tuberculosis should improve the quality of life of HIV-infected patients in Africa. (Résumé d'auteur

The possible role of local air pollution in climate change in West Africa

The climate of West Africa is characterized by a sensitive monsoon system that is associated with marked natural precipitation variability. This region has been and is projected to be subject to substantial global and regional-scale changes including greenhouse-gas-induced warming and sea-level rise, land-use and land-cover change, and substantial biomass burning. We argue that more attention should be paid to rapidly increasing air pollution over the explosively growing cities of West Africa, as experiences from other regions suggest that this can alter regional climate through the influences of aerosols on clouds and radiation, and will also affect human health and food security. We need better observations and models to quantify the magnitude and characteristics of these impacts

Eulerian conditional statistics of turbulent flow in a macroscale multi-inlet vortex chemical reactor

The conditional velocity time averages (⟨Ui|ξ⟩) and conditional mixture fraction time averages (⟨Φ|ωi⟩) were computed based on the Eulerian approach from the experimental data measured in a macroscale multi-inlet vortex chemical reactor. The conditioning events were determined by equally sized intervals of the sample space variable for the mixture fraction (ξ) and the velocity vector (ωi). The experimental data, which consisted of instantaneous velocities and concentration fields for two Reynolds numbers (Re = 3250 and 8125), were acquired using the simultaneous stereoscopic particle image velocimetry (stereo-PIV) and planar laser induced fluorescence techniques. Two mathematical models, the linear approximation and probability density function (PDF) gradient diffusion, were validated by experimental results. The results of the velocity conditioned on the mixture fraction demonstrated that the linear model works well in a low turbulence region away from the reactor center. Near the reactor center, high velocity gradients coupled with low concentration gradients reduce the accuracy of the linear model predictions. Nevertheless, an excellent agreement was found for the conditional events within ±2Φrms (mixture fraction root mean square). Due to lower concentration gradient in the tangential direction, the linear model better predicted the tangential velocity component for all locations investigated. The PDF model with an isotropic turbulent diffusivity performed inadequately for the tangential and axial velocity components. A modified version of the PDF model that considers the three components of the turbulent diffusivity produced a better agreement with the experimental data especially in the spiral arms regions of significant concentration gradients. Furthermore, the mixture fraction conditioned on the velocity vector components showed a more linear behavior near the reactor center, where the PDF of the mixture fraction is a Gaussian distribution. As the concentration gradients became prominent away from the reactor, ⟨Φ|ωi⟩ also deviated from the linear pattern. This was especially remarkable for the mixture fraction conditioned on the tangential velocity. The overall prediction of ⟨Φ|ωi⟩ improves at higher Reynolds number as the fluid mixing is enhanced

What will it cost to prevent violence against women and girls in low- and middle-income countries? Evidence from Ghana, Kenya, Pakistan, Rwanda, South Africa and Zambia

Violence against women and girls (VAWG) is a global problem with profound consequences. Although there is a growing body of evidence on the effectiveness of VAWG prevention interventions, economic data are scarce. We carried out a cross-country study to examine the costs of VAWG prevention interventions in low- and middle-income countries. We collected primary cost data on six different pilot VAWG prevention interventions in six countries: Ghana, Kenya, Pakistan, Rwanda, South Africa and Zambia. The interventions varied in their delivery platforms, target populations, settings and theories of change. We adopted a micro-costing methodology. We calculated total costs and a number of unit costs common across interventions (e.g. cost per beneficiary reached). We used the pilot-level cost data to model the expected total costs and unit costs of five interventions scaled up to the national level. Total costs of the pilots varied between ∼USD208 000 in a small group intervention in South Africa to USD2 788 000 in a couples and community-based intervention in Rwanda. Staff costs were the largest cost input across all interventions; consequently, total costs were sensitive to staff time use and salaries. The cost per beneficiary reached in the pilots ranged from ∼USD4 in a community-based intervention in Ghana to USD1324 for one-to-one counselling in Zambia. When scaled up to the national level, total costs ranged from USD32 million in Ghana to USD168 million in Pakistan. Cost per beneficiary reached at scale decreased for all interventions compared to the pilots, except for school-based interventions due to differences in student density per school between the pilot and the national average. The costs of delivering VAWG prevention vary greatly due to differences in the geographical reach, number of intervention components and the complexity of adapting the intervention to the country. Cost-effectiveness analyses are necessary to determine the value for money of interventions

SUSTAINABLE DEVELOPMENT OF AFRICAN NATURAL PLANT PRODUCTS

The development of sustainable agricultural businesses in high-value niche sectors can stimulate agricultural growth that could improve the livelihoods of rural Africa and have a multiplier effect on the rest of the economy. The natural plant product (NP) industry is one that can offer higher income and niche markets for resource limited farmers in developing countries compared to traditional agronomic crops. However, the NP industry is beset with challenges hindering the realization of its full contribution to economic development and poverty reduction. Among these challenges are: (1) limited appropriate germplasm; (2) lack of quality control and quality assurance systems for production and processing; (3) Lack of knowledge and understanding of international markets and markets channels; (4) Limited processing infrastructure which constrains value-added opportunities; (5) variable market prices, and (6) weak enterprises with low technical and managerial skills to meet the requirements of buyers. In 1999, we began to develop models for the sustainable commercialization of NP in sub-Sahara Africa using a market-first and scientific-driven approach. This program implemented under ASNAPP (www.asnapp.org) is conducted in partnership with the public and private sector to facilitate diversification of agricultural commodities and marketing channels. Sustainable development incorporates good environmental stewardship from the bush to final product, GAP and robust quality assurance and quality control systems for collection or cultivation to ensure high quality and food safety. This evolving model consists of a multi step value-addition process through the commodity chain to provide safe and high quality NPs and economic opportunities to those rural communities

Prevention of violence against women and girls: a cost-effectiveness study across 6 low- and middle-income countries

Background Violence against women and girls (VAWG) is a human rights violation with social, economic, and health consequences for survivors, perpetrators, and society. Robust evidence on economic, social, and health impact, plus the cost of delivery of VAWG prevention, is critical to making the case for investment, particularly in low- and middle-income countries (LMICs) where health sector resources are highly constrained. We report on the costs and health impact of VAWG prevention in 6 countries. Methods and findings We conducted a trial-based cost-effectiveness analysis of VAWG prevention interventions using primary data from 5 randomised controlled trials (RCTs) in sub-Saharan Africa and 1 in South Asia. We evaluated 2 school-based interventions aimed at adolescents (11 to 14 years old) and 2 workshop-based (small group or one to one) interventions, 1 community-based intervention, and 1 combined small group and community-based programme all aimed at adult men and women (18+ years old). All interventions were delivered between 2015 and 2018 and were compared to a do-nothing scenario, except for one of the school-based interventions (government-mandated programme) and for the combined intervention (access to financial services in small groups). We computed the health burden from VAWG with disability-adjusted life year (DALY). We estimated per capita DALYs averted using statistical models that reflect each trial’s design and any baseline imbalances. We report cost-effectiveness as cost per DALY averted and characterise uncertainty in the estimates with probabilistic sensitivity analysis (PSA) and cost-effectiveness acceptability curves (CEACs), which show the probability of cost-effectiveness at different thresholds. We report a subgroup analysis of the small group component of the combined intervention and no other subgroup analysis. We also report an impact inventory to illustrate interventions’ socioeconomic impact beyond health. We use a 3% discount rate for investment costs and a 1-year time horizon, assuming no effects post the intervention period. From a health sector perspective, the cost per DALY averted varies between 222 US dollars (2018), for an established gender attitudes and harmful social norms change community-based intervention in Ghana, to 17,548 US dollars (2018) for a livelihoods intervention in South Africa. Taking a societal perspective and including wider economic impact improves the cost-effectiveness of some interventions but reduces others. For example, interventions with positive economic impacts, often those with explicit economic goals, offset implementation costs and achieve more favourable cost-effectiveness ratios. Results are robust to sensitivity analyses. Our DALYs include a subset of the health consequences of VAWG exposure; we assume no mortality impact from any of the health consequences included in the DALYs calculations. In both cases, we may be underestimating overall health impact. We also do not report on participants’ health costs. Conclusions We demonstrate that investment in established community-based VAWG prevention interventions can improve population health in LMICs, even within highly constrained health budgets. However, several VAWG prevention interventions require further modification to achieve affordability and cost-effectiveness at scale. Broadening the range of social, health, and economic outcomes captured in future cost-effectiveness assessments remains critical to justifying the investment urgently required to prevent VAWG globally