Estimates of global, regional, and national incidence, prevalence, and mortality of HIV, 1980�2015: the Global Burden of Disease Study 2015

Background Timely assessment of the burden of HIV/AIDS is essential for policy setting and programme evaluation. In this report from the Global Burden of Disease Study 2015 (GBD 2015), we provide national estimates of levels and trends of HIV/AIDS incidence, prevalence, coverage of antiretroviral therapy (ART), and mortality for 195 countries and territories from 1980 to 2015. Methods For countries without high-quality vital registration data, we estimated prevalence and incidence with data from antenatal care clinics and population-based seroprevalence surveys, and with assumptions by age and sex on initial CD4 distribution at infection, CD4 progression rates (probability of progression from higher to lower CD4 cell-count category), on and off antiretroviral therapy (ART) mortality, and mortality from all other causes. Our estimation strategy links the GBD 2015 assessment of all-cause mortality and estimation of incidence and prevalence so that for each draw from the uncertainty distribution all assumptions used in each step are internally consistent. We estimated incidence, prevalence, and death with GBD versions of the Estimation and Projection Package (EPP) and Spectrum software originally developed by the Joint United Nations Programme on HIV/AIDS (UNAIDS). We used an open-source version of EPP and recoded Spectrum for speed, and used updated assumptions from systematic reviews of the literature and GBD demographic data. For countries with high-quality vital registration data, we developed the cohort incidence bias adjustment model to estimate HIV incidence and prevalence largely from the number of deaths caused by HIV recorded in cause-of-death statistics. We corrected these statistics for garbage coding and HIV misclassification. Findings Global HIV incidence reached its peak in 1997, at 3·3 million new infections (95 uncertainty interval UI 3·1�3·4 million). Annual incidence has stayed relatively constant at about 2·6 million per year (range 2·5�2·8 million) since 2005, after a period of fast decline between 1997 and 2005. The number of people living with HIV/AIDS has been steadily increasing and reached 38·8 million (95% UI 37·6�40·4 million) in 2015. At the same time, HIV/AIDS mortality has been declining at a steady pace, from a peak of 1·8 million deaths (95% UI 1·7�1·9 million) in 2005, to 1·2 million deaths (1·1�1·3 million) in 2015. We recorded substantial heterogeneity in the levels and trends of HIV/AIDS across countries. Although many countries have experienced decreases in HIV/AIDS mortality and in annual new infections, other countries have had slowdowns or increases in rates of change in annual new infections. Interpretation Scale-up of ART and prevention of mother-to-child transmission has been one of the great successes of global health in the past two decades. However, in the past decade, progress in reducing new infections has been slow, development assistance for health devoted to HIV has stagnated, and resources for health in low-income countries have grown slowly. Achievement of the new ambitious goals for HIV enshrined in Sustainable Development Goal 3 and the 90-90-90 UNAIDS targets will be challenging, and will need continued efforts from governments and international agencies in the next 15 years to end AIDS by 2030. Funding Bill & Melinda Gates Foundation, and National Institute of Mental Health and National Institute on Aging, National Institutes of Health. © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY licens

Estimation of stress concentration factor for a plate with hole under axial tension loading

The purpose of this study is to investigate the effects of hole/holes on stress concentrations in a plate using a current industry standard software - Finite Element Analysis (FEA). Plate with hole/holes is a common engineering application such as in automobile, marine, aerospace and mechanical structures. Hole/Holes can be seen in many thin-walled mechanical and automobile structures and components. For example, hole/holes are found in residential/commercial buildings’ steel structural studs to allow plumbing installation, web or flange of steel box girders in bridges is furnished with holes to ease inspection works, electrical and heating conduits in the walls or ceilings and ribs attached to the main spar of an aeroplane’s wing are frequently come with holes. These hole/holes are one type of discontinuities within the structure (e.g. thin plate) that leads to changes in elastic stiffness and may tend to failures. Proper knowledge of stresses, strains, deflection and stress concentration (SC) are required to design any structures. In the geometry of the plate, under different loading, stress concentration rises from any abrupt change. And due to this, throughout the cross-section, the uniform stress distribution does not occur. At a point of stress concentration, as a results failures like fatigue cracking and plastic deformation commonly occur. Hence, it is very important in any engineering structural design to know about the stress concentration on plates with holes. In the present study stress concentration in a plate with a circular central hole and offset hole subjected to uniaxial loading (axial tension) is calculated using Finite Element of Analysis (FEA). Equations of SCF given by Peterson are dependent on three parameters namely, hole radius (a), distance from the bottom edge to the centre of hole (c) and distance from top edge to centre of hole (e). By varying either ‘c’ or ‘e’ or the ratio of ‘e/c’, an effort is made to study stress concentration factors for the determination of the edge effect by varying the hole to edge distance. The results show that von Mises stresses increased with increasing ‘e/c’ or ‘a/c’, which in turn increases SCF and finally leads to failure