235 research outputs found
Strategies to Accelerate HIV Care and Antiretroviral Therapy Initiation After HIV Diagnosis: A Randomized Trial.
: Determine the effectiveness of strategies to increase linkage to care after testing HIV positive at mobile HIV testing in South Africa. : Unmasked randomized controlled trial. : Recruitment of adults testing HIV positive and not currently in HIV care occurred at 7 mobile HIV counseling and testing units in urban, periurban, and rural South Africa with those consenting randomized 1:1:1:1 into 1 of 4 arms. Three strategies were compared with standard of care (SOC): point-of-care CD4 count testing (POC CD4), POC CD4 plus longitudinal strengths-based counseling (care facilitation; CF), and POC CD4 plus transport reimbursement (transport). Participants were followed up telephonically and through clinic records and analyzed with an intention-to-treat analysis. : From March 2013 to October 2014, 2558 participants were enrolled, of whom 160 were excluded postrandomization. Compared with the SOC arm where 298 (50%) reported having entered care, linkage to care was 319 (52%) for POC CD4, hazard ratio (HR) 1.0 [95% confidence interval (CI): 0.89 to 1.2, P = 0.6]; 331 (55%) for CF, HR: 1.1 (95% CI: 0.84 to 1.3, P = 0.2); and 291 (49%) for transport, HR 0.97 (95% CI: 0.83 to 1.1, P = 0.7). Linkage to care verified with clinical records that occurred for 172 (29%) in the SOC arm; 187 (31%) in the POC CD4 arm, HR: 1.0 (95% CI: 0.86 to 1.3, P = 0.6); 225 (38%) in the CF arm, HR: 1.4 (95% CI: 1.1 to 1.7, P = 0.001); and 180 (31%) in the transport arm, HR: 1.1 (95% CI: 0.88 to 1.3, P = 0.5). : CF improved verified linkage to care from 29% to 38%.<br/
Food Sovereignty and Agricultural Land Use Planning: The Need to Integrate Public Priorities Across Jurisdictions
Recent calls for national food policies that promote greater food sovereignty represent an emerging concern of public policy. Such a shift in food policy toward greater citizen control over domestic food supplies would have significant implications for all aspects of the agri-food system. One area of concern is the conservation and use of agricultural land because, in the end, every act of producing and consuming food has direct or indirect impacts on the land base. Yet no research has considered the potential interactions and implications between food sovereignty and agricultural land use planning. This gap in research presents an opportunity to critically examine the effects of the changing roles and values on agricultural land use planning within and across jurisdictions. We believe that a better understanding of the dominant policy regimes within the agri-food system, including global competitiveness, farmland preservation, and food sovereignty, can lead to land use planning practices that are most beneficial for integrating not only multiple interests across jurisdictions, but also multiple perspectives
Plasma host protein biomarkers correlating with increasing Mycobacterium tuberculosis infection activity prior to tuberculosis diagnosis in people living with HIV
BACKGROUND: Biomarkers correlating with Mycobacterium tuberculosis infection activity/burden in asymptomatic individuals are urgently needed to identify and treat those at highest risk for developing active tuberculosis (TB). Our main objective was to identify plasma host protein biomarkers that change over time prior to developing TB in people living with HIV (PLHIV). METHODS: Using multiplex MRM-MS, we investigated host protein expressions from 2 years before until time of TB diagnosis in longitudinally collected (every 3-6 months) and stored plasma from PLHIV with incident TB, identified within a South African (SA) and US cohort. We performed temporal trend and discriminant analyses for proteins, and, to assure clinical relevance, we further compared protein levels at TB diagnosis to interferon-gamma release assay (IGRA; SA) or tuberculin-skin test (TST; US) positive and negative cohort subjects without TB. SA and US exploratory data were analyzed separately. FINDINGS: We identified 15 proteins in the SA (n=30) and 10 in the US (n=24) incident TB subjects which both changed from 2 years prior until time of TB diagnosis after controlling for 10% false discovery rate, and were significantly different at time of TB diagnosis compared to non-TB subjects (p<0.01). Five proteins, CD14, A2GL, NID1, SCTM1, and A1AG1, overlapped between both cohorts. Furthermore, after cross-validation, panels of 5 – 12 proteins were able to predict TB up to two years before diagnosis. INTERPRETATION: Host proteins can be biomarkers for increasing Mycobacterium tuberculosis infection activity/burden, incipient TB, and predict TB development in PLHIV. FUNDING: NIH/NIAID AI117927, AI146329, and AI127173 to JMA
Rat eradication comes within a whisker! A case study of a failed project from the South Pacific.
To enhance their conservation value, several hundred islands worldwide have been cleared of invasive alien rats, Rattus spp. One of the largest projects yet undertaken was on 43 km(2) Henderson Island in the Pitcairn group, South Pacific, in August 2011. Following massive immediate mortality, a single R. exulans was observed in March 2012 and, subsequently, rat numbers have recovered. The survivors show no sign of resistance to the toxicant used, brodifacoum. Using pre- and post-operation rat tissue samples from Henderson, plus samples from around the Pacific, we exclude re-introduction as the source of continued rat presence. Microsatellite analysis of 18 loci enabled comparison of genetic diversity of Henderson rats before and after the bait drop. The fall in diversity measured by allele frequency change indicated that the bottleneck (N e) through which the breeding population passed was probably around 50 individuals, representing a census population of about 60-80 animals. This is the first failed project that has estimated how close it was to success.The Darwin Initiative funded much of the RSPB’s work on Henderson Island and therefore sample collection and analysis, the latter also supported by the Sir Peter Scott Commemorative Expedition to the Pitcairn Islands
Safety and immunogenicity of H1/IC31®, an adjuvanted TB subunit vaccine, in HIV-infected adults with CD4+ lymphocyte counts greater than 350 cells/mm3: a phase II, multi-centre, double-blind, randomized, placebo-controlled trial.
BACKGROUND: Novel tuberculosis vaccines should be safe, immunogenic, and effective in various population groups, including HIV-infected individuals. In this phase II multi-centre, double-blind, placebo-controlled trial, the safety and immunogenicity of the novel H1/IC31 vaccine, a fusion protein of Ag85B-ESAT-6 (H1) formulated with the adjuvant IC31, was evaluated in HIV-infected adults. METHODS: HIV-infected adults with CD4+ T cell counts >350/mm3 and without evidence of active tuberculosis were enrolled and followed until day 182. H1/IC31 vaccine or placebo was randomly allocated in a 5:1 ratio. The vaccine was administered intramuscularly at day 0 and 56. Safety assessment was based on medical history, clinical examinations, and blood and urine testing. Immunogenicity was determined by a short-term whole blood intracellular cytokine staining assay. RESULTS: 47 of the 48 randomised participants completed both vaccinations. In total, 459 mild or moderate and 2 severe adverse events were reported. There were three serious adverse events in two vaccinees classified as not related to the investigational product. Local injection site reactions were more common in H1/IC31 versus placebo recipients (65.0% vs. 12.5%, p = 0.015). Solicited systemic and unsolicited adverse events were similar by study arm. The baseline CD4+ T cell count and HIV viral load were similar by study arm and remained constant over time. The H1/IC31 vaccine induced a persistent Th1-immune response with predominately TNF-α and IL-2 co-expressing CD4+ T cells, as well as polyfunctional IFN-γ, TNF-α and IL-2 expressing CD4+ T cells. CONCLUSION: H1/IC31 was well tolerated and safe in HIV-infected adults with a CD4+ Lymphocyte count greater than 350 cells/mm3. The vaccine did not have an effect on CD4+ T cell count or HIV-1 viral load. H1/IC31 induced a specific and durable Th1 immune response. TRIAL REGISTRATION: Pan African Clinical Trials Registry (PACTR) PACTR201105000289276
Comparison of laboratory costs of rapid molecular tests and conventional diagnostics for detection of tuberculosis and drug-resistant tuberculosis in South Africa.
BACKGROUND: The World Health Organization has endorsed the use of molecular methods for the detection of TB and drug-resistant TB as a rapid alternative to culture-based systems. In South Africa, the Xpert MTB/Rif assay and the GenoType MTBDRplus have been implemented into reference laboratories for diagnosis of TB and drug-resistance, but their costs have not been fully elucidated. METHODS: We conducted a detailed reference laboratory cost analysis of new rapid molecular assays (Xpert and MTBDRplus) for tuberculosis testing and drug-resistance testing in South Africa, and compared with the costs of conventional approaches involving sputum microscopy, liquid mycobacterial culture, and phenotypic drug sensitivity testing. RESULTS: From a laboratory perspective, Xpert MTB/RIF cost 23.46/sample, compared to $16.88/sample using conventional automated liquid culture-based methods. Laboratory costs of Xpert and MTBDRplus were most influenced by cost of consumables (60-80%). CONCLUSIONS: At current public sector pricing, Xpert MTB/RIF and MTBDRplus are comparable in cost to mycobacterial culture and conventional drug sensitivity testing. Overall, reference laboratories must balance costs with performance characteristics and the need for rapid results
Small contribution of gold mines to the ongoing tuberculosis epidemic in South Africa: a modeling-based study.
BACKGROUND: Gold mines represent a potential hotspot for Mycobacterium tuberculosis (Mtb) transmission and may be exacerbating the tuberculosis (TB) epidemic in South Africa. However, the presence of multiple factors complicates estimation of the mining contribution to the TB burden in South Africa. METHODS: We developed two models of TB in South Africa, a static risk model and an individual-based model that accounts for longer-term trends. Both models account for four populations - mine workers, peri-mining residents, labor-sending residents, and other residents of South Africa - including the size and prevalence of latent TB infection, active TB, and HIV of each population and mixing between populations. We calibrated to mine- and country-level data and used the static model to estimate force of infection (FOI) and new infections attributable to local residents in each community compared to other residents. Using the individual-based model, we simulated a counterfactual scenario to estimate the fraction of overall TB incidence in South Africa attributable to recent transmission in mines. RESULTS: We estimated that the majority of FOI in each community is attributable to local residents: 93.9% (95% confidence interval 92.4-95.1%), 91.5% (91.4-91.5%), and 94.7% (94.7-94.7%) in gold mining, peri-mining, and labor-sending communities, respectively. Assuming a higher rate of Mtb transmission in mines, 4.1% (2.6-5.8%), 5.0% (4.5-5.5%), and 9.0% (8.8-9.1%) of new infections in South Africa are attributable to gold mine workers, peri-mining residents, and labor-sending residents, respectively. Therefore, mine workers with TB disease, who constitute ~ 2.5% of the prevalent TB cases in South Africa, contribute 1.62 (1.04-2.30) times as many new infections as TB cases in South Africa on average. By modeling TB on a longer time scale, we estimate 63.0% (58.5-67.7%) of incident TB disease in gold mining communities to be attributable to recent transmission, of which 92.5% (92.1-92.9%) is attributable to local transmission. CONCLUSIONS: Gold mine workers are estimated to contribute a disproportionately large number of Mtb infections in South Africa on a per-capita basis. However, mine workers contribute only a small fraction of overall Mtb infections in South Africa. Our results suggest that curtailing transmission in mines may have limited impact at the country level, despite potentially significant impact at the mining level
Tuberculosis Prevention in South Africa
Background
South Africa has one of the highest per capita rates of tuberculosis (TB) incidence in the world. In 2012, the South African government produced a National Strategic Plan (NSP) to control the spread of TB with the ambitious aim of zero new TB infections and deaths by 2032, and a halving of the 2012 rates by 2016.
Methods
We used a transmission model to investigate whether the NSP targets could be reached if immediate scale up of control methods had happened in 2014. We explored the potential impact of four intervention portfolios; 1) “NSP” represents the NSP strategy, 2) “WHO” investigates increasing antiretroviral therapy eligibility, 3) “Novel Strategies” considers new isoniazid preventive therapy strategies and HIV “Universal Test and Treat” and 4) “Optimised” contains the most effective interventions.
Findings
We find that even with this scale-up, the NSP targets are unlikely to be achieved. The portfolio that achieved the greatest impact was “Optimised”, followed closely by “NSP”. The “WHO” and “Novel Strategies” had little impact on TB incidence by 2050. Of the individual interventions explored, the most effective were active case finding and reductions in pre-treatment loss to follow up which would have a large impact on TB burden.
Conclusion
Use of existing control strategies has the potential to have a large impact on TB disease burden in South Africa. However, our results suggest that the South African TB targets are unlikely to be reached without new technologies. Despite this, TB incidence could be dramatically reduced by finding and starting more TB cases on treatment
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