Prevalence and risk factors of obesity among undergraduate student population in Ghana: an evaluation study of body composition indices.

BACKGROUND: Obesity is a classified risk factor for several of the world's leading causes of death. In this study, we combined information contained in body mass index (BMI), total percentage body fat (TPBF) and relative fat mass (RFM) to estimate obesity prevalence and examine the risk factors associated with obesity. METHODS: The study recruited 1027 undergraduate students aged between 16 and 25 years using a cross-sectional study design and two-stage stratified random sampling between January and April 2019 from the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. Demographic, lifestyle, and family history of chronic disease data, were collected using a structured questionnaire. Bioelectrical impedance, along with height, weight, age, and gender, were used to estimate BMI and TPBF. The RFM was calculated using a published equation. The TPBF and RFM ranges were evaluated based on standard BMI thresholds and an informative combined obesity prevalence estimated in a Bayesian framework. Multiple logistic regression analysis was used to evaluate potential risk factors of overweight/obesity. RESULTS: Concordance between BMI, TPBF and RFM for obesity classification was 84% among female and 82.9% among male students. The Bayesian analysis revealed a combined prevalence means of obesity of 9.4% (95%CI: 6.9-12.2%) among female students and 6.7% (95%CI:4.3-9.5%) among male students. The odds of obesity were increased between 1.8 and 2.5 for females depending on the classification index. A significant increasing trend of obesity was observed with university-level. A family history of obesity was associated with a high estimate of general, central, and high TPBF. CONCLUSION: Using multiple adiposity indicators conjointly in a Bayesian framework offers a greater power to examine obesity prevalence. We have applied this and reported high obesity prevalence, especially among female students. University level and family history of obesity were key determinants for obesity among the student population.

Aberrant plasma IL-7 and soluble IL-7 receptor levels indicate impaired T-cell response to IL-7 in human tuberculosis.

T-cell proliferation and generation of protective memory during chronic infections depend on Interleukin-7 (IL-7) availability and receptivity. Regulation of IL-7 receptor (IL-7R) expression and signalling are key for IL-7-modulated T-cell functions. Aberrant expression of soluble (s) and membrane-associated (m) IL-7R molecules is associated with development of autoimmunity and immune failure in acquired immune deficiency syndrome (AIDS) patients. Here we investigated the role of IL-7/IL-7R on T-cell immunity in human tuberculosis. We performed two independent case-control studies comparing tuberculosis patients and healthy contacts. This was combined with follow-up examinations for a subgroup of tuberculosis patients under therapy and recovery. Blood plasma and T cells were characterised for IL-7/sIL-7R and mIL-7R expression, respectively. IL-7-dependent T-cell functions were determined by analysing STAT5 phosphorylation, antigen-specific cytokine release and by analysing markers of T-cell exhaustion and inflammation. Tuberculosis patients had lower soluble IL-7R (p < 0.001) and higher IL-7 (p < 0.001) plasma concentrations as compared to healthy contacts. Both markers were largely independent and aberrant expression normalised during therapy and recovery. Furthermore, tuberculosis patients had lower levels of mIL-7R in T cells caused by post-transcriptional mechanisms. Functional in vitro tests indicated diminished IL-7-induced STAT5 phosphorylation and impaired IL-7-promoted cytokine release of Mycobacterium tuberculosis-specific CD4+ T cells from tuberculosis patients. Finally, we determined T-cell exhaustion markers PD-1 and SOCS3 and detected increased SOCS3 expression during therapy. Only moderate correlation of PD-1 and SOCS3 with IL-7 expression was observed. We conclude that diminished soluble IL-7R and increased IL-7 plasma concentrations, as well as decreased membrane-associated IL-7R expression in T cells, reflect impaired T-cell sensitivity to IL-7 in tuberculosis patients. These findings show similarities to pathognomonic features of impaired T-cell functions and immune failure described in AIDS patients.

Dynamics of T-cell IFN-γ and miR-29a expression during active pulmonary tuberculosis.

IFN-γ is crucial for protection against Mycobacterium tuberculosis. miR-29 was recently shown to non-redundantly inhibit IFN-γ. Here, we investigated IFN-γ and miR-29a expression dynamics of CD4(+) T cells from patients during active tuberculosis (TB) (n = 32) and in household contacts who were latently M. tuberculosis infected (n = 19) from Ghana. Whereas M. tuberculosis-specific IFN-γ expression was similar during TB chemotherapy, superantigen stimulation indicated generally impaired IFN-γ expression in TB patients. No interdependency between miR-29a and IFN-γ expression of T cells was observed. However, miR-29a was differentially expressed in T cells during chemotherapy. We concluded that differential miR-29a expression in active TB was not causative for impaired IFN-γ expression.

A conceptual approach to the rationale for SARS-CoV-2 vaccine allocation prioritisation.

Currently vaccines protecting from COVID-19 are a scarce resource. Prioritising vaccination for certain groups of society is placed in a context of uncertainty due to changing evidence on the available vaccines and changing infection dynamics. To meet accepted ethical standards of procedural justice and individual autonomy, vaccine allocation strategies need to state reasons for prioritisation explicitly while at the same time communicating the expected risks and benefits of vaccination at different times and with different vaccines transparently. In this article, we provide a concept summarising epidemiological considerations underlying current vaccine prioritisation strategies in an accessible way. We define six priority groups (vulnerable individuals, persons in close contact with the vulnerable, key workers with direct work-related contact with the public, key workers without direct work-related contact to the public, dependents of key workers and members of groups with high interpersonal contact rates) and state vaccine priorities for them. Additionally, prioritisation may follow non-epidemiological considerations including the aim to increase intra-societal justice and reducing inequality. While national prioritisation plans integrate many of these concepts, the international community has so far failed to guarantee equitable or procedurally just access to vaccines across settings with different levels of wealth.

Seroprevalence of SARS-CoV-2 in urban settings in three sub-Saharan African countries (SeroCoV): a study protocol for a household-based cross-sectional prevalence study using two-stage cluster sampling.

INTRODUCTION: The current COVID-19 pandemic has impacted the entire world with increasing morbidity and mortality and has resulted in serious economic and social consequences. Assessing the burden of COVID-19 is essential for developing efficient pandemic preparedness and response strategies and for determining the impact of implemented control measures. Population-based seroprevalence surveys are critical to estimate infection rates, monitor the progression of the epidemic and to allow for the identification of persons exposed to the infection who may either have been asymptomatic or were never tested. This is especially important for countries where effective testing and tracking systems could not be established and where non-severe cases or under-reported deaths might have blurred the true burden of COVID-19. Most seroprevalence surveys performed in sub-Saharan Africa have targeted specific high risk or more easily accessible populations such as healthcare workers or blood donors, and household-based estimates are rarely available. Here, we present the study protocol for a SARS-CoV-2 seroprevalence estimation in the general population of Burkina Faso, Ghana and Madagascar in 2021. METHODS AND ANALYSIS: The SeroCoV study is a household-based cross-sectional prevalence investigation in persons aged 10 years and older living in urban areas in six cities using a two-stage geographical cluster sampling method stratified by age and sex. The presence of anti-SARS-CoV-2 IgG antibodies will be determined using a sensitive and specific SARS-CoV-2 IgG ELISA. In addition, questionnaires will cover sociodemographic information, episodes of diseases and history of testing and treatment for COVID-like symptoms, travel history and safety measures. We will estimate the seroprevalence of SARS-CoV-2, taking into account test performance and adjusting for the age and sex of the respective populations. ETHICS AND DISSEMINATION: Ethical approval was received for all participating countries. Results will be disseminated through reports and presentations at the country level as well as peer-reviewed publications and international scientific conferences presentations.

Constitutive STAT3 phosphorylation and IL-6/IL-10 co-expression are associated with impaired T-cell function in tuberculosis patients.

T-cells critically contribute to protection against Mycobacterium tuberculosis infection, and impaired T-cell responses can lead to disease progression. Pro-inflammatory and immunosuppressive cytokines affect T-cells, and fine-tuned regulation of cytokine signaling via the Jak/STAT signaling pathways is crucial for appropriate T-cell function. Constitutive STAT3 phosphorylation as a consequence of aberrant cytokine signaling has been described to occur in pathognomonic T-cell responses in inflammatory and autoimmune diseases. We characterized blood samples from tuberculosis patients (n=28) and healthy contacts (n=28) from Ghana for M. tuberculosis-specific T-cell responses, constitutive cytokine production, and SOCS3 and pSTAT3 expression. Lentiviral modulation of primary CD4+ T-cells was performed to determine the effects of SOCS3 on T-cell functions. T-cells from tuberculosis patients expressed higher levels of IL-10 and IL-6 and lower levels of T helper type (TH)17 cytokines after M. tuberculosis-specific stimulation compared to healthy contacts. In addition, tuberculosis patients had higher IL-10 and IL-6 levels in the supernatants of non-stimulated immune cells and plasma samples compared to healthy contacts. Notably, aberrant cytokine expression was accompanied by high constitutive pSTAT3 levels and SOCS3 expression in T-cells. Multivariate analysis identified an IL-6/IL-10 co-expression-based principal component in tuberculosis patients that correlated with high pSTAT3 levels. SOCS3 contributed to a regulatory component, and tuberculosis patients with high SOCS3 expression showed decreased TH1 cytokine expression and impaired IL-2-induced STAT5 phosphorylation. SOCS3 over-expression in primary CD4+ T-cells confirmed the SOCS3 inhibitory function on IL-2-induced STAT5 phosphorylation. We conclude that constitutive pSTAT3 and high SOCS3 expression are influential factors that indicate impaired T-cell functions in tuberculosis patients.