Higher SARS-CoV-2 seroprevalence in workers with lower socioeconomic status in Cape Town, South Africa.

BACKGROUND: Inequality is rife throughout South Africa. The first wave of COVID-19 may have affected people in lower socioeconomic groups worse than the affluent. The SARS-CoV-2 seroprevalence and the specificity of anti-SARS-CoV-2 antibody tests in South Africa is not known. METHODS: We tested 405 volunteers representing all socioeconomic strata from the workforce of a popular shopping and tourist complex in central Cape Town with the Abbott SARS-CoV-2 IgG assay. We assessed the association between antibody positivity and COVID-19 symptom status, medical history, and sociodemographic variables. We tested 137 serum samples from healthy controls collected in Cape Town prior to the COVID-19 pandemic, to confirm the specificity of the assay in the local population. RESULTS: Of the 405 volunteers tested one month after the first peak of the epidemic in Cape Town, 96(23.7%) were SARS-CoV-2 IgG positive. Of those who tested positive, 46(47.9%) reported no symptoms of COVID-19 in the previous 6 months. Seropositivity was significantly associated with living in informal housing, residing in a subdistrict with low income-per household, and having a low-earning occupation. The specificity of the assay was 98.54%(95%CI 94.82%-99.82%) in the pre-COVID controls. CONCLUSIONS: There is a high background seroprevalence in Cape Town, particularly in people of lower socioeconomic status. Almost half of cases are asymptomatic, and therefore undiagnosed by local testing strategies. These results cannot be explained by low assay specificity.

Disease characteristics and treatment of patients with diabetes mellitus attending government health services in Indonesia, Peru, Romania and South Africa.

OBJECTIVE: To describe the characteristics and management of Diabetes mellitus (DM) patients from low- and middle-income countries (LMIC). METHODS: We systematically characterised consecutive DM patients attending public health services in urban settings in Indonesia, Peru, Romania and South Africa, collecting data on DM treatment history, complications, drug treatment, obesity, HbA1c and cardiovascular risk profile; and assessing treatment gaps against relevant national guidelines. RESULTS: Patients (median 59 years, 62.9% female) mostly had type 2 diabetes (96%), half for >5 years (48.6%). Obesity (45.5%) and central obesity (females 84.8%; males 62.7%) were common. The median HbA1c was 8.7% (72 mmol/mol), ranging from 7.7% (61 mmol/mol; Peru) to 10.4% (90 mmol/mol; South Africa). Antidiabetes treatment included metformin (62.6%), insulin (37.8%), and other oral glucose-lowering drugs (34.8%). Disease complications included eyesight problems (50.4%), EGFR <60 ml/min (18.9%), heart disease (16.5%) and proteinuria (14.7%). Many had an elevated cardiovascular risk with elevated blood pressure (36%), LDL (71.0%) and smoking (13%), but few were taking antihypertensive drugs (47.1%), statins (28.5%) and aspirin (30.0%) when indicated. Few patients on insulin (8.0%), statins (8.4%) and antihypertensives (39.5%) reached treatment targets according to national guidelines. There were large differences between countries in terms of disease profile and medication use. CONCLUSION: DM patients in government clinics in four LMIC with considerable growth of DM have insufficient glycaemic control, frequent macrovascular and other complications, and insufficient preventive measures for cardiovascular disease. These findings underline the need to identify treatment barriers and secure optimal DM care in such settings.

Assessment of Validity of a Blood-Based 3-Gene Signature Score for Progression and Diagnosis of Tuberculosis, Disease Severity, and Treatment Response.

Importance: The World Health Organization identified the need for a non-sputum-based triage test to identify those in need of further tuberculosis (TB) testing. Objective: To determine whether the 3-gene TB score can be a diagnostic tool throughout the course of TB disease, from latency to diagnosis to treatment response, and posttreatment residual inflammation. Design, Setting, and Participants: This nested case-control study analyzed the 3-gene TB score in 3 cohorts, each focusing on a different stage of TB disease: (1) the Adolescent Cohort Study profiled whole-blood samples from adolescents with latent Mycobacterium tuberculosis infection, some of which progressed to active TB (ATB), using RNA sequencing; (2) the Brazil Active Screen Study collected whole blood from an actively screened case-control cohort of adult inmates from 2 prisons in Mato Grosso do Sul, Brazil, for ATB from January 2016 to February 2016; and (3) the Catalysis Treatment Response Cohort (CTRC) identified culture-positive adults in primary health care clinics in Cape Town, South Africa, from 2005 to 2007 and collected whole blood for RNA sequencing from patients with ATB at diagnosis and weeks 1, 4, and 24. The CTRC patients also had positron emission tomography-computed tomography scans at diagnosis, week 4, and week 24. Analyses were performed from September 2017 to June 2018. Main Outcomes and Measures: A 3-gene messenger RNA expression score, measured by quantitative polymerase chain reaction or RNA sequencing, was evaluated for distinguishing the following: individuals who progressed to ATB from those who did not, individuals with ATB from those without, and individuals with slower treatment response during TB therapy. Results: Patients evaluated in this study included 144 adolescents from the Adolescent Cohort Study (aged 12-18 years; 96 female and 48 male), 81 adult prison inmates from the Brazil Active Screen Study (aged 20-72 years; 81 male), and 138 adult community members from the CTRC (aged 17-64 years; 81 female and 57 male). The 3-gene TB score identified progression from latent M tuberculosis infection to ATB 6 months prior to sputum conversion with 86% sensitivity and 84% specificity (area under the curve [AUC], 0.86; 95% CI, 0.77-0.96) and patients with ATB in the Brazil Active Screen Study cohort (AUC, 0.87; 95% CI, 0.78-0.95) and CTRC (AUC, 0.94; 95% CI, 0.88-0.99). It also identified CTRC patients with failed treatment at the end of treatment (AUC, 0.93; 95% CI, 0.83-1.00). Collectively, across all cohorts, the 3-gene TB score identified patients with ATB with 90% sensitivity, 70% specificity, and 99.3% negative predictive value at 4% prevalence. Conclusions and Relevance: Across 3 independent prospective cohorts, the 3-gene TB score approaches the World Health Organization target product profile benchmarks for non-sputum-based triage test with high negative predictive value. This gene expression diagnostic approach should be considered for further validation and future implementation.

Biomarkers for TB treatment response: challenges and future strategies.

Currently the ultimate success of anti-TB therapy is measured by the relapse rate within the first 2 years after treatment. The long duration of clinical trials that rely on this outcome constitute a disincentive for the pharmaceutical industry to develop new TB drugs. Biomarkers for relapse measurable during early treatment may shorten clinical trials. Additionally pre-treatment markers could allow stratification of patients into groups with different treatment requirements for improved clinical management. Currently there is a lack of sufficiently validated biomarkers with good individual predictive value and an urgent need for candidate markers and their evaluation in prospective studies. This review provides an overview of novel biomarkers for TB treatment response and outcome focusing on immunological markers in serum. Additionally, the challenges and roadblocks biomarker research is currently faced with are highlighted.

TB: a partnership for the benefit of research and community.

A public-private partnership (PPP) involving Stellenbosch University in South Africa and GlaxoSmithKline (GSK) has benefited both research and a local community where tuberculosis (TB) is endemic. The venture, part of GSK's Action TB programme, enabled the University's Desmond Tutu TB Centre to establish an epidemiological field site in two suburbs of Cape Town where the annual risk of TB infection is 3.5%. Collaboration between the centre and GSK focused on the development of a surrogate marker model able to predict patient outcome with relative accuracy. Such models may be useful tools for diagnosis/prognosis and for shortening clinical trials of novel TB agents. Other research findings stemming from the Action TB partnership suggest that exogenous reinfection is responsible for the majority of relapse cases and that adults often have infection with multiple strains. The local community has been empowered by the implementation of the Directly Observed Treatment, Short-course (DOTS) programme and benefited from improved education about health in general and TB in particular. The centre has also provided employment for many local people in field work and other roles. Meanwhile, national and international publicity about the centre's work has aided in generating the essential political will to allocate resources and shape healthcare priorities, benefiting this impoverished community.