scholarly journals Bimodal distribution and set point HBV DNA viral loads in chronic infection: retrospective analysis of cohorts from the UK and South Africa

2020 ◽  
Vol 5 ◽  
pp. 113
Author(s):  
Louise O. Downs ◽  
Sabeehah Vawda ◽  
Phillip Armand Bester ◽  
Katrina A. Lythgoe ◽  
Tingyan Wang ◽  
...  
Keyword(s):  
South Africa ◽  
Population Level ◽  
Bimodal Distribution ◽  
Skewed Distribution ◽  
Stable Set ◽  
Cross Sectional ◽  
Set Point ◽  
Viral Loads ◽  
The Uk ◽  
The Right

Hepatitis B virus (HBV) viral load (VL) is used as a biomarker to assess risk of disease progression, and to determine eligibility for treatment. While there is a well recognised association between VL and the expression of the viral e-antigen (HBeAg) protein, the precise determinants and distribution of VL at a population level are not well described. We here report the distribution of HBV VL in two large cross-sectional population cohorts in the UK and in South Africa, demonstrating a consistent bimodal distribution. The right skewed distribution and low median viral loads are significantly different from the left-skew and higher viraemia in seen in comparable HIV and hepatitis C virus (HCV) cohorts. Using longitudinal data, we present evidence for a stable ‘set-point’ VL in peripheral blood during chronic HBV infection. These results are important to underpin improved understanding of HBV biology and to plan public health interventions.

scholarly journals Bimodal distribution and set point HBV DNA viral loads in chronic infection: retrospective analysis of cohorts from the UK and South Africa

2020 ◽  
Vol 5 ◽  
pp. 113
Author(s):  
Louise O. Downs ◽  
Sabeehah Vawda ◽  
Phillip Armand Bester ◽  
Katrina A. Lythgoe ◽  
Tingyan Wang ◽  
...  
Keyword(s):  
South Africa ◽  
Large Population ◽  
Population Level ◽  
Bimodal Distribution ◽  
Skewed Distribution ◽  
Stable Set ◽  
Cross Sectional ◽  
Set Point ◽  
Viral Loads ◽  
The Uk

Hepatitis B virus (HBV) viral load (VL) is used as a biomarker to assess risk of disease progression, and to determine eligibility for treatment. While there is a well recognised association between VL and the expression of the viral e-antigen protein, the distributions of VL at a population level are not well described. We here present cross-sectional, observational HBV VL data from two large population cohorts in the UK and in South Africa, demonstrating a consistent bimodal distribution. The right skewed distribution and low median viral loads are different from the left-skew and higher viraemia in seen in HIV and hepatitis C virus (HCV) cohorts in the same settings. Using longitudinal data, we present evidence for a stable ‘set-point’ VL in peripheral blood during chronic HBV infection. These results are important to underpin improved understanding of HBV biology, to inform approaches to viral sequencing, and to plan public health interventions.

scholarly journals Bimodal distribution and set point HBV DNA viral loads in chronic infection: retrospective analysis of cohorts from the UK and South Africa

2020 ◽  
Author(s):  
Louise O Downs ◽  
Sabeehah Vawda ◽  
Phillip Armand Bester ◽  
Katrina A Lythgoe ◽  
Tingyan Wang ◽  
...  
Keyword(s):  
South Africa ◽  
Hepatitis B ◽  
Bimodal Distribution ◽  
Hbv Dna ◽  
Set Point ◽  
Viral Loads ◽  
B Virus ◽  
Chronic Hbv ◽  
The Uk ◽  
Host Characteristics

AbstractHepatitis B virus (HBV) DNA viral loads (VL) show wide variation between individuals with chronic hepatitis B (CHB) infection, and are used to determine treatment eligibility. There are few refined descriptions of VL distribution in CHB, and limited understanding of the biology that underpins these patterns. We set out to describe the VL distribution in independent cohorts from the UK and South Africa, to identify associated host characteristics, and to compare with VL in HIV-1 and hepatitis C (HCV) infection. We show the presence of a set-point in chronic HBV infection and report significant differences in the viral load distribution of HBV when compared to HIV and HCV.

scholarly journals Iodine and pregnancy – a UK cross-sectional survey of dietary intake, knowledge and awareness

2015 ◽  
Vol 114 (1) ◽  
pp. 108-117 ◽  
Author(s):  
E. Combet ◽  
M. Bouga ◽  
B. Pan ◽  
M. E. J. Lean ◽  
C. O. Christopher
Keyword(s):  
Iodine Intake ◽  
Dietary Recommendations ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Nutritional Recommendations ◽  
Level Of Confidence ◽  
Healthy Growth ◽  
The Uk ◽  
The Right ◽  
In Pregnancy

Iodine is a key component of the thyroid hormones, which are critical for healthy growth, development and metabolism. The UK population is now classified as mildly iodine-insufficient. Adequate levels of iodine during pregnancy are essential for fetal neurodevelopment, and mild iodine deficiency is linked to developmental impairments. In the absence of prophylaxis in the UK, awareness of nutritional recommendations during pregnancy would empower mothers to make the right dietary choices leading to adequate iodine intake. The present study aimed to: estimate mothers' dietary iodine intake in pregnancy (using a FFQ); assess awareness of the importance of iodine in pregnancy with an understanding of existing pregnancy dietary and lifestyle recommendations with relevance for iodine; examine the level of confidence in meeting adequate iodine intake. A cross-sectional survey was conducted and questionnaires were distributed between August 2011 and February 2012 on local (Glasgow) and national levels (online electronic questionnaire); 1026 women, UK-resident and pregnant or mother to a child aged up to 36 months participated in the study. While self-reported awareness about general nutritional recommendations during pregnancy was high (96 %), awareness of iodine-specific recommendations was very low (12 %), as well as the level of confidence of how to achieve adequate iodine intake (28 %). Median pregnancy iodine intake, without supplements, calculated from the FFQ, was 190 μg/d (interquartile range 144–256μg/d), which was lower than that of the WHO's recommended intake for pregnant women (250 μg/d). Current dietary recommendations in pregnancy, and their dissemination, are found not to equip women to meet the requirements for iodine intake.

scholarly journals Evaluation of multi-assay algorithms for identifying individuals with recent HIV infection: HPTN 071 (PopART)

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0258644
Author(s):  
Wendy Grant-McAuley ◽  
Ethan Klock ◽  
Oliver Laeyendecker ◽  
Estelle Piwowar-Manning ◽  
Ethan Wilson ◽  
...  
Keyword(s):  
Viral Suppression ◽  
Point Of Care ◽  
Population Level ◽  
Hiv Viral Load ◽  
Cross Sectional ◽  
Individual Level ◽  
Viral Loads ◽  
Incidence Estimation ◽  
Duration Of Infection ◽  
Recent Hiv Infection

Background Assays and multi-assay algorithms (MAAs) have been developed for population-level cross-sectional HIV incidence estimation. These algorithms use a combination of serologic and/or non-serologic biomarkers to assess the duration of infection. We evaluated the performance of four MAAs for individual-level recency assessments. Methods Samples were obtained from 220 seroconverters (infected <1 year) and 4,396 non-seroconverters (infected >1 year) enrolled in an HIV prevention trial (HPTN 071 [PopART]); 28.6% of the seroconverters and 73.4% of the non-seroconverters had HIV viral loads ≤400 copies/mL. Samples were tested with two laboratory-based assays (LAg-Avidity, JHU BioRad-Avidity) and a point-of-care assay (rapid LAg). The four MAAs included different combinations of these assays and HIV viral load. Seroconverters on antiretroviral treatment (ART) were identified using a qualitative multi-drug assay. Results The MAAs identified between 54 and 100 (25% to 46%) of the seroconverters as recently-infected. The false recent rate of the MAAs for infections >2 years duration ranged from 0.2%-1.3%. The MAAs classified different overlapping groups of individuals as recent vs. non-recent. Only 32 (15%) of the 220 seroconverters were classified as recent by all four MAAs. Viral suppression impacted the performance of the two LAg-based assays. LAg-Avidity assay values were also lower for seroconverters who were virally suppressed on ART compared to those with natural viral suppression. Conclusions The four MAAs evaluated varied in sensitivity and specificity for identifying persons infected <1 year as recently infected and classified different groups of seroconverters as recently infected. Sensitivity was low for all four MAAs. These performance issues should be considered if these methods are used for individual-level recency assessments.

scholarly journals Association between RT-PCR Ct Values and COVID-19 New Daily Cases: A Multicenter Cross-Sectional Study

2020 ◽  
Author(s):  
Abdulkarim Abdulrahman ◽  
Saad Mallah ◽  
Abdulla Ismael AlAwadhi ◽  
Simone Perna ◽  
Essam Janahi ◽  
...  
Keyword(s):  
Population Studies ◽  
Population Level ◽  
Female Gender ◽  
Cross Sectional Study ◽  
Newly Diagnosed ◽  
Sectional Study ◽  
Rt Pcr ◽  
Cross Sectional ◽  
Viral Loads ◽  
Epidemiological Changes

Introduction: Proactive prediction of the epidemiologic dynamics of viral diseases and outbreaks of the likes of COVID-19 has remained a difficult pursuit for scientists, public health researchers, and policymakers. It is unclear whether RT-PCR Cycle Threshold (Ct) values of COVID-19 (or any other virus) as indicator of viral load, could represent a possible predictor for underlying epidemiological changes on a population level. Objectives: To investigate whether population-wide changes in SARS-CoV-2 RT-PCR Ct values over time are associated with the daily fraction of positive COVID-19 tests. In addition, this study analyses the factors that could influence the RT-PCR Ct values. Method: A retrospective cross-sectional study was conducted on 63,879 patients from May 4, 2020 to September 30, 2020, in all COVID-19 facilities in the Kingdom of Bahrain. Data collected included number of tests and newly diagnosed cases, as well as Ct values, age, gender nationality, and symptomatic status. Results: Ct values were found to be negatively and very weakly correlated with the fraction of daily positive cases in the population r = -0.06 (CI95%: -0.06; -0.05; p=0.001). The R-squared for the regression model (adjusting for age and number of daily tests) showed an accuracy of 45.3%. Ct Values showed an association with nationality (p=0.012). After the stratification, the association between Ct values and the fraction of daily positive cases was only maintained for the female gender and Bahraini-nationality. Symptomatic presentation was significantly associated with lower Ct values (higher viral loads). Ct values do not show any correlation with age (p=0.333) or gender (p=0.522). Conclusion: We report one of the first and largest studies to investigate the epidemiological associations of Ct values with COVID-19. Ct values offer a potentially simple and widely accessible tool to predict and model epidemiological dynamics on a population level. More population studies and predictive models from global cohorts are necessary.

scholarly journals Enforcement of corporate rights-the rule in Foss v Harbottle: Dead or alive

2016 ◽  
Vol 12 (1) ◽  
pp. 6-14 ◽  
Author(s):  
Anthony O. Nwafor
Keyword(s):  
South Africa ◽  
Detailed Examination ◽  
Minority Shareholders ◽  
The Real ◽  
Corporate Rights ◽  
Right Of Action ◽  
The Uk ◽  
The Right

The principle on the enforcement of a corporation’s right of action which is encapsulated as the rule in Foss v Harbottle has continued to attract discombobulating academic and judicial comments in defining the scope and exceptions to that rule. The recent statutory interventions which are witnessed in the UK and South Africa by redefining the right of the minority shareholders and other persons to intervene in the corporation’s right of action are seen by some writers as having extinguished the flame ignited by the decision in Foss v Harbottle. A detailed examination of the real purport of Wigram VC’s pronouncement in that case is undertaken, streamlining the rule and the subsequent decisions of courts carving out rooms for departure from the rule. The paper argues that the statutory interventions in jurisdictions under discussion only borders on derivative action which is an exception to the rule. The effect of those statutory provisions on the rule itself is not too significant as would justify the suggestion that the rule is now extinct. Thus, the paper concludes that the rule in Foss v Harbottle remains the principal approach to the enforcement of a corporation’s right of action.

scholarly journals Prevalence and causes of visual impairment and blindness among adults with diabetes mellitus aged 40 years and older receiving treatment at government health facilities in the Mopani District, South Africa

2014 ◽  
Vol 73 (1) ◽  
Author(s):  
R.G. Mabaso ◽  
O.A. Oduntan
Keyword(s):  
Diabetes Mellitus ◽  
South Africa ◽  
Visual Impairment ◽  
Economic Status ◽  
Health Care Facilities ◽  
Health Facilities ◽  
Cross Sectional ◽  
Government Health ◽  
The Government ◽  
The Right

This article presents part of the findings of a study conducted to assess the prevalence and causes of visual impairment (VI) and blindness among adults with diabetes mellitus (DM) receiving treatment at the government health facilities in the Mopani District, South Africa.  This health facility-based cross-sectional study was conducted among 225 Black South African diabetics (161 females and 64 males) aged 40-90 years (mean= 61.50 ± 10.49) years at seven different health care facilities. All the participants were examined for VI using an auto-refractor, pinhole disc, an ophthalmoscope, and a logMAR chart. Visual impairment was defined as visual acuity (VA) of worse than 6/9.5 but better and equal to 3/60, and blindness as VA of worse than 3/60 to no light perception. The prevalence of uncompensated VI and blindness in the right eyes was 70.6 and 3.6%, respectively. In the left eyes, the prevalence was 72 and 3.1% for VI and blindness respectively. The prevalence of blindness remained the same after optical compensation. The leading causes of uncompensated VI and blindness in both eyes were uncorrected refractive error (RE) (49.5%), cataract (24.7%), diabetic retinopathy (3.8%) and glaucoma (2.2%). Following optical compensation, the prevalence of compensated VI and blindness in the right eyes was 41.3 and 3.6%, respectively and in the left eyes, the prevalence was 42.2 and 3.1%, respectively. Uncompensated RE and cataract were the common causes of VI and blindness in this sample. The socio-economic status of this population might have contributed to these findings. These results indicate the need for affordable vision examination and spectacles provision as well as cataract surgery services in this population.

scholarly journals Making sense of mixed-embeddedness in migrant informal enterprising

2019 ◽  
Vol 25 (5) ◽  
pp. 974-995 ◽  
Author(s):  
Angelo P. Bisignano ◽  
Imad El-Anis
Keyword(s):  
Asylum Seekers ◽  
Legal Status ◽  
Current Approach ◽  
Cross Sectional ◽  
Content Type ◽  
Theoretical Contribution ◽  
Market Opportunities ◽  
Migrant Entrepreneurs ◽  
The Uk ◽  
The Right

PurposeThe purpose of this paper is to discuss how informal migrant entrepreneurs with different legal statuses interpret their mixed-embeddedness in social and economic contexts. Legal status represents a key determinant in shaping accessible social networks and market opportunities that in turn influence entrepreneurial choices.Design/methodology/approachThe paper adopts an interpretative stance to explore how migrant entrepreneurs interpret mixed-embeddedness. It draws on the empirical evidence from a cross-sectional sample of 26 asylum seekers that engaged with enterprising activities in the city of Nottingham in the UK. A recursive hermeneutic process guided the iterative readings of the accounts to develop theoretical insights on how these agents reinvent their relationship with structure.FindingsA novel theoretical framework emerges from the data analysis to present how these particular migrants use understandings of community and notions of capital to make sense of their mixed-embeddedness. The main theoretical contribution of the framework is to illustrate how groups with different legal statuses produce unique interpretations of mixed-embeddedness. This, in turn, reflects onto specific forms of enterprising and innovative entrepreneurial choices. The framework also produces an empirical contribution as it re-centres the analysis of mixed-embeddedness around the migrant entrepreneur from previous meso- and macro-level perspectives that dominated recent research.Research limitations/implicationsThe paper expands knowledge on the notion of mixed-embeddedness by providing insights on how informal migrant entrepreneurs make sense of it. This can form the basis for allowing scholars to address empirically how migrant entrepreneurs reconcile their embeddedness in both social and economic contexts. In terms of practical implications, the paper paves the way for policy-makers to re-evaluate the current approach to the right of asylum seekers to pursue entrepreneurial activities.Originality/valueThe notion of mixed-embeddedness is central to research on informal migrant enterprising. Nevertheless, the concept remains fuzzy and difficult to operationalise. The paper offers an opportunity to understand how migrant entrepreneurs make sense of mixed-embeddedness so that future scholars can better explore how mixed-embeddedness reconciles agency and structure.

scholarly journals State Responsibility and the Question of Expropriation: A Preliminary to the “Land Expropriation without Compensation” Policy in South Africa

2019 ◽  
Vol 12 (1) ◽  
pp. 98 ◽  
Author(s):  
Abdul Hamid Kwarteng ◽  
Thomas Prehi Botchway
Keyword(s):  
South Africa ◽  
International Law ◽  
Land Reform ◽  
Due Process ◽  
Research Approach ◽  
Cross Sectional ◽  
Foreign Investors ◽  
Critical Issues ◽  
The Government ◽  
The Right

Expropriation is a right granted to States under international law; however this right does not guarantee States to abuse their power to unlawfully seize properties without following due process or paying the right compensation. In August 2018, the president of South Africa proposed a bill that would allow the government to expropriate land without compensation and this bill has attracted the attention of both scholars of international law and foreign investors. With a qualitative approach and a cross sectional analysis of data, this article seeks to analyze the nature of this bill to determine whether it infringes on the principles and practice of international law, as well as the likely consequences that the bill could have on the global image of South Africa and foreign direct investment in the country. The research approach allowed the authors to analyze important literature while making inferences to cases of expropriation in different parts of the world and juxtaposing them with South Africa&rsquo;s intended policy. The article concludes that one of the main critical issues for determining the lawful nature of expropriation is that it should be accompanied by an appropriate, adequate, effective, and prompt compensation, and as such not only does this bill constitute to a breach of international law but it will also damage the economy by scaring foreign investors away. In addition, the State would be compelled to spend millions of the already limited resources of the country in defending itself against international lawsuits that will be filed by affected individuals. It is thus suggested that a much better approach for land reform should be adopted by the government in its quest for development.

scholarly journals Link between the numbers of particles and variants founding new HIV-1 infections depends on the timing of transmission

2018 ◽  
Author(s):  
Robin N. Thompson ◽  
Chris Wymant ◽  
Rebecca A. Spriggs ◽  
Jayna Raghwani ◽  
Christophe Fraser ◽  
...  
Keyword(s):  
Population Level ◽  
Epidemiological Data ◽  
Heterosexual Transmission ◽  
Next Generation Sequencing Data ◽  
Viral Population ◽  
Sequencing Data ◽  
Set Point ◽  
Viral Loads ◽  
Multiple Variants ◽  
Hiv 1

ABSTRACTUnderstanding which HIV-1 variants are most likely to be transmitted is important for vaccine design and predicting virus evolution. Since most infections are founded by single variants, it has been suggested that selection at transmission has a key role in governing which variants are transmitted. We show that the composition of the viral population within the donor at the time of transmission is also important. To support this argument, we developed a probabilistic model describing HIV-1 transmission in an untreated population, and parameterised the model using both within-host next generation sequencing data and population-level epidemiological data on heterosexual transmission. The most basic HIV-1 transmission models cannot explain simultaneously the low probability of transmission and the non-negligible proportion of infections founded by multiple variants. In our model, transmission can only occur when environmental conditions are appropriate (e.g. abrasions are present in the genital tract of the potential recipient), allowing these observations to be reconciled. As well as reproducing features of transmission in real populations, our model demonstrates that, contrary to expectation, there is not a simple link between the number of viral variants and the number of viral particles founding each new infection. These quantities depend on the timing of transmission, and infections can be founded with small numbers of variants yet large numbers of particles. Including selection, or a bias towards early transmission (e.g. due to treatment) acts to enhance this conclusion. In addition, we find that infections initiated by multiple variants are most likely to have derived from donors with intermediate set-point viral loads, and not from individuals with high set-point viral loads as might be expected. We therefore emphasise the importance of considering viral diversity in donors, and the timings of transmissions, when trying to discern the complex factors governing single or multiple variant transmission.

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