scholarly journals The added value of recent-infection testing in population-based HIV surveys

2021 ◽  
Author(s):  
Laurette Mhlanga ◽  
Eduard Grebe ◽  
Alex Welte
Keyword(s):  
Sexual Debut ◽  
Survey Design ◽  
Value Added ◽  
Early Years ◽  
Added Value ◽  
Hiv Incidence ◽  
Recent Infection ◽  
Cross Sectional ◽  
Marginal Benefit ◽  
Incidence Trends

Abstract Background: There is no clear consensus on how best to use increasingly available data derived from large populationbased surveys featuring HIV infection status ascertainment. In particular, for the purpose of estimating HIV incidence, there is considerable scope for better elucidation of the benefit of adding ‘recent infection’ ascertainment, which adds considerable additional cost and complexity to surveys which are already costly and complex. Methods: Using an epidemic/survey simulation tool developed for this and some closely related investigations, we explore the value added by ‘recent infection’ data from population surveys, to support HIV incidence estimation. This directly piggy-backs on to two companion pieces which have explored, independently, the use of the ‘synthetic cohort’ paradigm of Mahiane et al (analysing age/time structure of prevalence, in conjunction with estimates of mortality) and the paradigm of Kassanjee et al (focusing on ‘recent infection’ data). Results: Our headline findings are that: 1) Recent infection data adds marginal benefit to surveillance focused on the early years after sexual debut, which can reasonably be taken to be a core sentinel group in which surveillance is significantly more efficient than attempts to cover all ages; and 2) by contrast, recent infection data is crucial for the reliable estimation of incidence trends when only two cross sectional surveys are available. We detail numerous components of a general and robust approach to analysing data when both the Mahiane and Kassanjee analyses are in play. Conclusion: Our main results present non-trivial dilemmas for survey design, as recency data is crucial for stabilising the more timely estimates, but of marginal benefit for the most important sentinel group. We hope that adaptation of our analysis, to simulated scenarios closely aligned to specific contexts facing expensive choices, will support rational investments in, and use of, precious surveillance opportunities and data sets.

scholarly journals Optimal accounting for age and time structure of HIV incidence estimates based on cross-sectional survey data with ascertainment of ‘recent infection’

2021 ◽  
Author(s):  
Laurette Mhlanga ◽  
Grebe Eduard ◽  
Alex Welte
Keyword(s):  
Survey Data ◽  
Age Structure ◽  
Estimation Procedure ◽  
Time Dependent ◽  
Data Sets ◽  
Hiv Incidence ◽  
Recent Infection ◽  
Cross Sectional ◽  
Incidence Estimation ◽  
Dependent Mortality

Abstract BackgroundMany surveys have attempted to estimate HIV incidence from cross-sectional data which includes ascertainment of ‘recent infection’, but the inevitable age and time structure of this data has never been systematically explored – no doubt partly because statistical precision in such estimates is often insufficient to allow for satisfactory disaggregation. Given the non-trivial age structure of HIV incidence and prevalence, and the enormous investments that have been made in such data sets, it is important to understand effective ways to extract valid age structure from these precious data sets. MethodsUsing a comprehensive demographic/epidemiological simulation platform developed for this, and some wider, purposes (documented in more detail separately) we simulated a complex ‘South Africa inspired’ HIV epidemic, with explicitly specified 1) age/time dependent incidence, 2) age/time dependent mortality for uninfected individuals, and 3) age/time/time-since-infection dependent mortality for infected individuals. In this simulated world, we conducted cross-sectional surveys at various times, and applied variants of the recent infection based incidence estimation methodology of Kassanjee et al. We analysed in considerable detail how to smooth, and average over, the age structure in these surveys to produce the incidence estimates, paying attention to the fundamental trade-off between bias and statistical error.ResultsWe summarise our detailed observations about incidence estimates, generated by various age smoothing or age disaggregation procedures, into a straightforward fully specified ‘one size fits most’ algorithm for processing the survey data into age-specific incidence estimates: 1) generalised linear regression to turn observations into ‘prevalence’ of ‘infection’ and ‘recent infection’ (logit, and complementary log log, link functions, respectively; fitting coefficients of up to cubic terms in age/time); 2) a ‘moving window’ data inclusion recipe which handles each age/time point of interest separately; 3) post hoc age averaging of resulting pseudo continuously fitted incidence; 4) bootstrapping as a generic variance/significance estimation procedure.ConclusionsAs far as we are aware, this is the first analysis of several fine details of how age structure in cross-sectional surveys interacts with recency-based incidence estimation. Our proposed default estimation procedure generates incidence estimates with negligible bias and near-optimal precision, and can be readily applied to complex survey data sets by any group in possession of such data. Our code is available, in part freely through the R computing platform, and in part upon request.

scholarly journals Using tests for recent infection to estimate incidence: problems and prospects for HIV

2010 ◽  
Vol 15 (24) ◽  
Author(s):  
A Welte ◽  
T A McWalter ◽  
O Laeyendecker ◽  
T B Hallett
Keyword(s):  
Future Development ◽  
Theoretical Work ◽  
Incidence Rates ◽  
Hiv Incidence ◽  
Unified Framework ◽  
Cross Sectional Survey ◽  
Recent Infection ◽  
Cross Sectional ◽  
Recent Theoretical Work ◽  
Survey Sample

Tests for recent infection (TRIs), such as the BED assay, provide a convenient way to estimate HIV incidence rates from cross-sectional survey data. Controversy has arisen over how the imperfect performance of a TRI should be characterised and taken into account. Recent theoretical work is providing a unified framework within which to work with a variety of TRI- and epidemic-specific assumptions in order to estimate incidence using imperfect TRIs, but suggests that larger survey sample sizes will be required than previously thought. This paper reviews the framework qualitatively and provides examples of estimator performance, identifying the characteristics required by a TRI to estimate incidence reliably that should guide the future development of TRIs.

scholarly journals Recent HIV infection among pregnant women in the 2017 antenatal sentinel cross–sectional survey, South Africa: Assay–based incidence measurement

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249953
Author(s):  
Selamawit Woldesenbet ◽  
Tendesayi Kufa-Chakezha ◽  
Carl Lombard ◽  
Samuel Manda ◽  
Mireille Cheyip ◽  
...  
Keyword(s):  
South Africa ◽  
Pregnant Women ◽  
Young Women ◽  
Reference Group ◽  
Hiv Positive ◽  
Hiv Incidence ◽  
Cross Sectional Survey ◽  
Recent Infection ◽  
Cross Sectional ◽  
One Year

Introduction New HIV infection during pre-conception and pregnancy is a significant contributor of mother–to–child transmission of HIV in South Africa. This study estimated HIV incidence (defined as new infection within the last one year from the time of the survey which included both new infections occurred during pregnancy or just before pregnancy) among pregnant women and described the characteristics of recently infected pregnant women at national level. Methods Between 1 October and 15 November 2017, we conducted a national cross–sectional survey among pregnant women aged 15–49 years old attending antenatal care at 1,595 public facilities. Blood specimens were collected from pregnant women and tested for HIV in a centralised laboratory. Plasma viral load and Limiting Antigen Avidity Enzyme Immunosorbent Assay (LAg) tests were further performed on HIV positive specimens to differentiate between recent and long–term infections. Recent infection was defined as infection that occurred within one year from the date of collection of blood specimen for the survey. Data on age, age of partner, and marital status were collected through interviews. Women whose specimens were classified as recent by LAg assay and with viral loads >1,000 copies/mL were considered as recently infected. The calculated proportion of HIV positive women with recent infection was adjusted for assay–specific parameters to estimate annual incidence. Survey multinomial logistic regression was used to examine factors associated with being recently infected using HIV negative women as a reference group. Age–disparate relationship was defined as having a partner 5 or more years older. Results Of 10,049 HIV positive participants with LAg and viral load data, 1.4% (136) were identified as recently infected. The annual HIV incidence was 1.5% (95% confidence interval (CI): 1.2–1.7). In multivariable analyses, being single (adjusted odds ratio, aOR: 3.4, 95% CI: 1.8–6.2) or cohabiting (aOR: 3.8, 95% CI: 1.8–7.7), compared to being married as well as being in an age–disparate relationship among young women (aOR: 3.1, 95% CI: 2.0–4.7; reference group: young women (15–24years) whose partners were not 5 years or more older) were associated with higher odds of recent infection. Conclusions Compared to previous studies among pregnant women, the incidence estimated in this study was substantially lower. However, the UNAIDS target to reduce incidence by 75% by 2020 (which is equivalent to reducing incidence to <1%) has not been met. The implementation of HIV prevention and treatment interventions should be intensified, targeting young women engaged in age–disparate relationship and unmarried women to fast track progress towards the UNAIDS target.

scholarly journals Regional disparity of HIV incidence and prevalence among men who have sex with men

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
D. N. Vergara-Ortega ◽  
H. López-Gatell ◽  
S. Bautista-Arredondo ◽  
A. Colchero ◽  
S. G. Sosa-Rubí ◽  
...  
Keyword(s):  
Regional Differences ◽  
Sexual Debut ◽  
Wealth Index ◽  
National Sample ◽  
Molecular Data ◽  
Hiv Prevalence ◽  
Hiv Incidence ◽  
Cross Sectional ◽  
Geographical Regions ◽  
Sex With Men

Abstract Background HIV incidence can be estimated with cross-sectional studies using clinical, serological, and molecular data. Worldwide, HIV incidence data in only men who have sex with men (MSM) are scarce and principally focus on those with healthcare or under treatment. However, better estimates can be obtained through studies with national representativeness. The objective was to estimate the prevalence, incidence, and factors associated with acquiring HIV in a national sample of MSM who attend meeting places, considering geographical regions. Methods A nationally representative survey of MSM attending meeting places was performed in Mexico. Participants answered a questionnaire, and a dried blood spot (DBS) was collected. Samples were classified as recent infections using an algorithm with HIV status, antiretroviral therapy, and the result of BED-EIA assay. Parameters were analysed considering regions and demographic and sexual behaviour characteristics. Results The national HIV prevalence was 17.4% with regional differences; the highest prevalence (20.7%) was found in Mexico City, and the lowest prevalence was found in the West region (11.5%). The incidence was 9.4 per 100 p/y, with regional values from 6.2 to 13.2 for the Northeast and the Centre regions, respectively. Age, age at sexual debut, low wealth index, and rewarded sex were associated with HIV prevalence. Centre region, use of private clinics as health services, and having sex exclusively with men were associated with recent HIV infections. Conclusions The incidence and prevalence showed regional differences, suggesting a difference in the dynamics of HIV transmission; some regions have a greater case accumulation, and others have a greater rate of new infections. Understanding this dynamic will allow developing health programs focused on HIV prevention or treating people already living with HIV.

scholarly journals Optimal accounting for age and time structure of HIV incidence estimates based on cross-sectional survey data with ascertainment of ‘recent infection’

2021 ◽  
Author(s):  
Laurette Mhlanga ◽  
Grebe Eduard ◽  
Alex Welte
Keyword(s):  
Survey Data ◽  
Age Structure ◽  
Estimation Procedure ◽  
Time Dependent ◽  
Data Sets ◽  
Hiv Incidence ◽  
Recent Infection ◽  
Cross Sectional ◽  
Incidence Estimation ◽  
Dependent Mortality

Abstract BackgroundMany surveys have attempted to estimate HIV incidence from cross-sectional data which includes ascertainment of ‘recent infection’, but the inevitable age and time structure of this data has never been systematically explored – no doubt partly because statistical precision in such estimates is often insufficient to allow for satisfactory disaggregation. Given the non-trivial age structure of HIV incidence and prevalence, and the enormous investments that have been made in such data sets, it is important to understand effective ways to extract valid age structure from these precious data sets. MethodsUsing a comprehensive demographic/epidemiological simulation platform developed for this, and some wider, purposes (documented in more detail separately) we simulated a complex ‘South Africa inspired’ HIV epidemic, with explicitly specified 1) age/time dependent incidence, 2) age/time dependent mortality for uninfected individuals, and 3) age/time/time-since-infection dependent mortality for infected individuals. In this simulated world, we conducted cross-sectional surveys at various times, and applied variants of the recent infection based incidence estimation methodology of Kassanjee et al. We analysed in considerable detail how to smooth, and average over, the age structure in these surveys to produce the incidence estimates, paying attention to the fundamental trade-off between bias and statistical error.ResultsWe summarise our detailed observations about incidence estimates, generated by various age smoothing or age disaggregation procedures, into a straightforward fully specified ‘one size fits most’ algorithm for processing the survey data into age-specific incidence estimates: 1) generalised linear regression to turn observations into ‘prevalence’ of ‘infection’ and ‘recent infection’ (logit, and complementary log log, link functions, respectively; fitting coefficients of up to cubic terms in age/time); 2) a ‘moving window’ data inclusion recipe which handles each age/time point of interest separately; 3) post hoc age averaging of resulting pseudo continuously fitted incidence; 4) bootstrapping as a generic variance/significance estimation procedure.ConclusionsAs far as we are aware, this is the first analysis of several fine details of how age structure in cross-sectional surveys interacts with recency-based incidence estimation. Our proposed default estimation procedure generates incidence estimates with negligible bias and near-optimal precision, and can be readily applied to complex survey data sets by any group in possession of such data. Our code is available, in part freely through the R computing platform, and in part upon request.

scholarly journals Cross-Sectional HIV Incidence Surveillance: A Benchmarking of Approaches for Estimating the ‘Mean Duration of Recent Infection’

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Reshma Kassanjee ◽  
Daniela De Angelis ◽  
Marian Farah ◽  
Debra Hanson ◽  
Jan Phillipus Lourens Labuschagne ◽  
...  
Keyword(s):  
Random Effects ◽  
Hiv Incidence ◽  
Recent Infection ◽  
Cross Sectional ◽  
Loss To Follow Up ◽  
Missed Visits ◽  
The Mean ◽  
Substantial Bias ◽  
Similar Accuracy ◽  
Study Designs

AbstractThe application of biomarkers for ‘recent’ infection in cross-sectional HIV incidence surveillance requires the estimation of critical biomarker characteristics. Various approaches have been employed for using longitudinal data to estimate the Mean Duration of Recent Infection (MDRI) – the average time in the ‘recent’ state. In this systematic benchmarking of MDRI estimation approaches, a simulation platform was used to measure accuracy and precision of over twenty approaches, in thirty scenarios capturing various study designs, subject behaviors and test dynamics that may be encountered in practice. Results highlight that assuming a single continuous sojourn in the ‘recent’ state can produce substantial bias. Simple interpolation provides useful MDRI estimates provided subjects are tested at regular intervals. Regression performs the best – while ‘random effects’ describe the subject-clustering in the data, regression models without random effects proved easy to implement, stable, and of similar accuracy in scenarios considered; robustness to parametric assumptions was improved by regressing ‘recent’/‘non-recent’ classifications rather than continuous biomarker readings. All approaches were vulnerable to incorrect assumptions about subjects’ (unobserved) infection times. Results provided show the relationships between MDRI estimation performance and the number of subjects, inter-visit intervals, missed visits, loss to follow-up, and aspects of biomarker signal and noise.

PERCEIVED EFFECTS OF STREET HAWKING ON THE WELL-BEING OF CHILDREN IN ANYIGBA, DEKINA LOCAL GOVERNMENT AREA OF KOGI STATE, NIGERIA

2018 ◽  
Vol 8 (1) ◽  
pp. 01-07
Author(s):  
Alfred Eboh
Keyword(s):  
Local Government ◽  
Survey Design ◽  
Sampling Technique ◽  
Well Being ◽  
Local Government Area ◽  
Negative Consequences ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Perceived Effects ◽  
The Government

Background: The hawking of wares by children has been a serious issue confronting the Nigerian society. Children hawk in some of the most horrible conditions conceivable, where they face a serious risk of injury, chronic illness, kidnapping, rape or death. Objective: The focus of this study was to assess the perceived effects of street hawking on the well-being of children in Anyigba, Dekina Local Government Area of Kogi State. Methods: The population of this study consists of parents of the street hawkers in Anyigba while cross-sectional survey design was used through the purposive sampling technique to choose the sample size of one hundred and sixty-two (162) respondents. The validated structured questionnaire and In-Depth Interviews (IDIs) served as the instruments for the data collection respectively. The hypotheses were tested using Chi-Square at a predetermined 0.05 level of significance. The quantitative data were analysed with the aid of the SPSS (version 20). Results: The results indicated among others that street hawking had significant social implications and physical consequences on children's moral behaviour as well as health status in the study area. Conclusion: The study, therefore, concluded that the government of Kogi State should carry out an enlightenment campaign through the media and religious institutions on the negative consequences of street hawking are recommended as panacea. Also, the child right act instrument and its implementation should be strengthened in order to curb street hawking in the study area.

Implementasi Analisis Proses Bisnis Sebagai Upaya Pengurangan Biaya

2019 ◽  
Vol 10 (1) ◽  
pp. 1-27
Author(s):  
Aniek Wijayanti
Keyword(s):  
Business Process ◽  
Cost Reduction ◽  
Process Analysis ◽  
Value Added ◽  
Added Value ◽  
Natural Material ◽  
Management Activity ◽  
Procurement Process ◽  
Material Procurement ◽  
The Cost

Business Process Analysis can be used to eliminate or reduce a waste cost caused by non value added activities that exist in a process. This research aims at evaluating activities carried out in the natural material procurement process in the PT XYZ, calculating the effectiveness of the process cycle, finding a way to improve the process management, and calculating the cost reduction that can achieved by activity management. A case study was the approach of this research. The researcher obtained research data throughout deep interviews with the staff who directly involved in the process, observation, and documentation of natural material procurement. The result of this study show that the effectiveness of the process cycle of natural material procurement in the factory reached as much as 87,1% for the sand material and 72% for the crushed stone. This indicates that the process still carry activities with no added value and still contain ineffective costs. Through the Business Process Mechanism, these non value added activities can be managed so that the process cycle becomes more efficient and cost effectiveness is achieved. The result of the effective cycle calculation after the management activities implementation is 100%. This means that the cost of natural material procurement process has become effective. The result of calculation of the estimated cost reduction as a result of management activity is as much as Rp249.026.635,90 per year.

Corporate Social Responsibility Practices in Bank: A Case of Bangladesh

2020 ◽  
Author(s):  
Dalowar Hossan
Keyword(s):  
Corporate Social Responsibility ◽  
Social Responsibility ◽  
Positive Reaction ◽  
Survey Design ◽  
Business Community ◽  
Policy Implications ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Corporate Social ◽  
Self Administered Questionnaire

The purpose of this article is to examine the influence of corporate social responsibility practices of Dutch-Bangla Bank Limited (DBBL), Bangladesh and to know the client’s knowledge, feedback, awareness and eagerness towards the CSR activities while choosing a bank. This study also investigates the level of present and expected CSR contribution of this bank. A cross- sectional survey design was used for the study featuring a self administered questionnaire and data were collected from 100 clients at South Surma branch. Data were analyzed using SPSS and the findings revealed that CSR activities played an important role for clients to choose a bank. Most of the clients were aware of CSR program and they had positive reaction to CSR practices of DBBL. Clients also suggested to expand CSR practices and they were willing to contribute for social activities financially. The results show the policy implications for business community, citizen, customers, investors, managers and other stakeholders.

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