Transmission networks and risk of HIV infection in KwaZulu-Natal, South Africa : a community-wide phylogenetic study.

CAPRISA, 2017.Abstract available in pdf

Bland-Altman plots comparing the reference laboratory test with the 3 point-of-care assays in phase 1 (left column) and phase 2 (right column).

<p>In phase 1 of the study the STAT-Site had a high failure rate. It seems that this was related to uneven migration of the sample through the sample strip, resulting in the sample migration time exceeding the maximum time specified by the manufacturer.</p

Diagnostic Accuracy of the HemoCue Hb 301, STAT-Site M^Hgb and URIT-12 Point-of-Care Hemoglobin Meters in a Central Laboratory and a Community Based Clinic in Durban, South Africa

<div><p>In South Africa, various point-of-care hemoglobin meters are used. However, the regulatory framework for approval, implementation and oversight of use of point-of-care hemoglobin meters is suboptimal. We assessed the diagnostic accuracy of the HemoCue Hb 301, STAT-Site M^Hgb and URIT-12 point-of-care hemoglobin meters, compared to a central laboratory based reference assay, in a central laboratory and a community based clinic in Durban, South Africa. Differences in performance of the point-of-care assays, compared to the reference assay, were more pronounced in the community based clinic. Results were reasonable for the HemoCue Hb 301, but poor for the STAT-Site M^Hgb and the URIT-12. Poor test performance of point-of-care hemoglobin meters, and inadequate evaluations and oversight in South Africa, leads to suboptimal clinical care and clinical research, and increased costs. There is a need for proper evaluation and quality assurance of point-of-care tests, the results of which should be made widely available to key stakeholders.</p></div

Correlation of the 3 point-of-care assays with values within the dynamic range of the reference Hemoglobin meter in 60 samples in a central laboratory (phase 1), and 100 samples in a community based clinical setting (phase 2).

<p>In phase 1 of the study the STAT-Site had a high failure rate. It seems that this was related to uneven migration of the sample through the sample strip, resulting in the sample migration time exceeding the maximum time specified by the manufacturer.</p

Phase 2 (community based clinical setting) sensitivity, specificity, and predictive values for the 3 point-of-care tests to detect or exclude anemia.

<p>Phase 2 (community based clinical setting) sensitivity, specificity, and predictive values for the 3 point-of-care tests to detect or exclude anemia.</p

Correlation of the 3 point-of-care assays with values within the dynamic range of the reference hemoglobin meter in 100 samples in a community based clinical setting in phase 2 of the study.

<p>Dots in the blue quadrant indicate that the point-of-care assay missed anemia, i.e., misclassified a finger prick sample as non-anemic where the venous blood sample was classified as anemic according to the reference assay in a central laboratory. Dots in the red quadrant indicate that the point-of-care assay misclassified as anemic a sample that was non-anemic according to the reference assay.</p

Leveraging ongoing research to evaluate the health impacts of South Africa\u27s salt reduction strategy: a prospective nested cohort within the WHO-SAGE multicountry, longitudinal study

Introduction: Attempting to curb the rising epidemic of hypertension, South Africa implemented legislation in June 2016 mandating maximum sodium levels in a range of manufactured foods that contribute significantly to population salt intake. This natural experiment, comparing two African countries with and without salt legislation, will provide timely information on the impact of legislative approaches addressing the food supply to improve blood pressure in African populations. This article outlines the design of this ongoing prospective nested cohort study. Methods and analysis: Baseline sodium intake was assessed in a nested cohort of the WHO Study on global AGEing and adult health (WHO-SAGE) wave 2 (2014-2015), a multinational longitudinal study on the health and well-being of adults and the ageing process. The South African cohort consisted of randomly selected households (n=4030) across the country. Spot and 24-hour urine samples are collected in a random subsample (n=1200) and sodium, potassium, creatinine and iodine analysed. Salt behaviour and sociodemographic data are captured using face-to-face interviews, alongside blood pressure and anthropometric measures. Ghana, the selected control country with no formal salt policy, provided a nested subsample (n=1200) contributing spot and 24-hour urine samples from the SAGE Ghana cohort (n=5000). Follow-up interviews and urine collection (wave 3) in both countries will take place in 2017 (postlegislation) to assess change in population-level sodium intake and blood pressure. Ethics and dissemination: SAGE was approved by the WHO Ethics Review Committee (reference number RPC149) with local approval from the North-West University Human Research Ethics Committee and University of the Witwatersrand Human Research Ethics Committee (South Africa), and University of Ghana Medical School Ethics and Protocol Review Committee (Ghana). The results of the study will be published in peer-reviewed international journals, presented at national and international conferences, and summarised as research and policy briefs

Transmission networks and risk of HIV infection in KwaZulu-Natal, South Africa: a community-wide phylogenetic study

Summary Background The incidence of HIV infection in young women in Africa is very high. We did a large-scale community-wide phylogenetic study to examine the underlying HIV transmission dynamics and the source and consequences of high rates of HIV infection in young women in South Africa. Methods We did a cross-sectional household survey of randomly selected individuals aged 15–49 years in two neighbouring subdistricts (one urban and one rural) with a high burden of HIV infection in KwaZulu-Natal, South Africa. Participants completed structured questionnaires that captured general demographic, socioeconomic, psychosocial, and behavioural data. Peripheral blood samples were obtained for HIV antibody testing. Samples with HIV RNA viral load greater than 1000 copies per mL were selected for genotyping. We constructed a phylogenetic tree to identify clusters of linked infections (defi ned as two or more sequences with bootstrap or posterior support ≥90% and genetic distance ≤4·5%). Findings From June 11, 2014, to June 22, 2015, we enrolled 9812 participants, 3969 of whom tested HIV positive. HIV prevalence (weighted) was 59·8% in 2835 women aged 25–40 years, 40·3% in 1548 men aged 25–40 years, 22·3% in 2224 women younger than 25 years, and 7·6% in 1472 men younger than 25 years. HIV genotyping was done in 1589 individuals with a viral load of more than 1000 copies per mL. In 90 transmission clusters, 123 women were linked to 103 men. Of 60 possible phylogenetically linked pairings with the 43 women younger than 25 years, 18 (30·0%) probable male partners were younger than 25 years, 37 (61·7%) were aged 25–40 years, and fi ve (8·3%) were aged 41–49 years: mean age diff erence 8·7 years (95% CI 6·8–10·6; p<0·0001). For the 92 possible phylogenetically linked pairings with the 56 women aged 25–40 years, the age diff erence dropped to 1·1 years (95% CI –0·6 to 2·8; p=0·111). 16 (39·0%) of 41 probable male partners linked to women younger than 25 years were also linked to women aged 25–40 years. Of 79 men (mean age 31·5 years) linked to women younger than 40 years, 62 (78·5%) were unaware of their HIV-positive status, 76 (96·2%) were not on antiretroviral therapy, and 29 (36·7%) had viral loads of more than 50 000 copies per mL. Interpretation Sexual partnering between young women and older men, who might have acquired HIV from women of similar age, is a key feature of the sexual networks driving transmission. Expansion of treatment and combination prevention strategies that include interventions to address age-disparate sexual partnering is crucial to reducing HIV incidence and enabling Africa to reach the goal of ending AIDS as a public health threat. Funding President’s Emergency Program for AIDS Relief, US Centers for Disease Control and Prevention, South African Medical Research Council, and MAC AIDS Fund