scholarly journals Performance and Logistical Challenges of Alternative HIV-1 Virological Monitoring Options in a Clinical Setting of Harare, Zimbabwe

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Pascale Ondoa ◽  
Tinei Shamu ◽  
Michelle Bronze ◽  
Maureen Wellington ◽  
Tamara Sonia Boender ◽  
...  
Keyword(s):  
Virological Failure ◽  
Low Cost ◽  
Quality Care ◽  
Assay Sensitivity ◽  
Load Monitoring ◽  
Test Version ◽  
High Level ◽  
Virological Monitoring ◽  
Hiv 1

We evaluated a low-cost virological failure assay (VFA) on plasma and dried blood spot (DBS) specimens from HIV-1 infected patients attending an HIV clinic in Harare. The results were compared to the performance of the ultrasensitive heat-denatured p24 assay (p24). The COBAS AmpliPrep/COBAS TaqMan HIV-1 test, version 2.0, served as the gold standard. Using a cutoff of 5,000 copies/mL, the plasma VFA had a sensitivity of 94.5% and specificity of 92.7% and was largely superior to the VFA on DBS (sensitivity = 61.9%; specificity = 99.0%) or to the p24 (sensitivity = 54.3%; specificity = 82.3%) when tested on 302 HIV treated and untreated patients. However, among the 202 long-term ART-exposed patients, the sensitivity of the VFA decreased to 72.7% and to 35.7% using a threshold of 5,000 and 1,000 RNA copies/mL, respectively. We show that the VFA (either on plasma or on DBS) and the p24 are not reliable to monitor long-term treated, HIV-1 infected patients. Moreover, achieving acceptable assay sensitivity using DBS proved technically difficult in a less-experienced laboratory. Importantly, the high level of virological suppression (93%) indicated that quality care focused on treatment adherence limits virological failure even when PCR-based viral load monitoring is not available.

scholarly journals Robust Recall and Long-Term Memory T-Cell Responses Induced by Prime-Boost Regimens with Heterologous Live Viral Vectors Expressing Human Immunodeficiency Virus Type 1 Gag and Env Proteins

2002 ◽  
Vol 76 (15) ◽  
pp. 7506-7517 ◽  
Author(s):  
Karl Haglund ◽  
Ingrid Leiner ◽  
Kristen Kerksiek ◽  
Linda Buonocore ◽  
Eric Pamer ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Vaccinia Virus ◽  
Human Immunodeficiency Virus Type ◽  
Long Term Memory ◽  
Term Memory ◽  
Immunodeficiency Virus ◽  
High Level ◽  
Hiv 1

ABSTRACT We investigated long-term memory and recall cellular immune responses to human immunodeficiency virus type 1 (HIV-1) Env and Gag proteins elicited by recombinant vesicular stomatitis viruses (VSVs) expressing Env and Gag. More than 7 months after a single vaccination with VSV-Env, ∼6% of CD8+ splenocytes stained with major histocompatibility complex class I tetramers containing the Env p18-I10 immunodominant peptide and showed a memory phenotype (CD44Hi). The level of tetramer-positive cells in memory was about 14% of the peak primary response. Recall responses elicited in these mice 5 days after boosting with a heterologous recombinant vaccinia virus expressing HIV-1 Env showed that 40 to 45% of CD8+ splenocytes were tetramer positive and activated (CD62LLo), and these cells produced gamma interferon after stimulation with Env peptide, indicating that they were functional. Five months after the boost, the long-term memory cell population (tetramer positive, CD44Hi) constituted 30% of the CD8+ splenocytes. Recall responses to HIV-1 Gag were examined in mice primed with VSV recombinants expressing HIV-1 Gag protein and boosted with a vaccinia virus recombinant expressing Gag. Using this protocol, we found that ∼40% of CD8+ splenocytes were activated (CD62LLo) and specific for a Gag immunodominant peptide (tetramer positive). The high-level Gag recall response elicited by the vaccinia virus-Gag was greater than that obtained by boosting with a VSV-Gag vector with a different VSV glycoprotein. The corresponding levels of CD44Hi memory cells were also higher long after boosting with vaccinia virus-Gag than after boosting with a glycoprotein exchange VSV-Gag. Our results show that VSV vectors elicit high-level memory CTL responses and that these can be amplified as much as six- to sevenfold using a heterologous boosting vector.

scholarly journals Factors associated with high-risk low-level viremia leading to virologic failure: 16-year retrospective study of a Chinese antiretroviral therapy cohort

2019 ◽  
Author(s):  
Tong Zhang ◽  
Haibo Ding ◽  
Minghui An ◽  
Xiaonan Wang ◽  
Wen Tian ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
High Risk ◽  
Virologic Failure ◽  
Baseline Viral Load ◽  
Factors Associated ◽  
Low Level ◽  
Subtype B ◽  
High Level ◽  
Hiv 1

Abstract Background: Low level viremia (LLV) often occurs during antiretroviral therapy (ART) against HIV-1. However, its impact on virologic failure (VF) is controversial because of non-uniform definitions of LLV and VF. Methods: A long-term first line regimen ART cohort from 2002–2018 from Shenyang, northeast China, was retrospectively studied. All participants were followed up every 3 to 6 months to evaluate the treatment effect. The high-risk LLV subgroups leading to VF (with strict standards) were explored with Cox proportional hazards model and linear mixed-effect model. The association factors of high-risk LLV were further explored using multivariate logistic regression analyses. Results: A total of 2155 HIV-1 infected participants were included; of these, 38.8% showed LLV. Both high level LLV (HLLV) and any other level LLV coupled with high level blip (HBL) showed higher risk of VF (hazards ratios, HRHLLV=5.93, and HRHBL=2.84, p<0.01 respectively). Moreover, HR increased with prolonged duration of LLV. Independent factors associated with high-risk LLV included the zenith baseline viral load (VL) above 6 log copies/ml (aOR=3.49, p=0.002), nadir baseline CD4+T cell counts below 200 cells/ml (aOR=1.78, p=0.011), Manchu (aOR=2.03, p=0.003), ART over 60 months (aOR=1.81, p=0.004), AZT+3TC+NVP (aOR=2.26, p<0.001) or DDI-based regimen (aOR=9.96, p<0.001), and subtype B’ infection (aOR=8.22, p=0.001). Conclusions: In case of VF with strict standards, high-risk LLV leading to VF includes VL above 400 copies/ml, occurring at least once. Serious laboratory indicators or advanced stage of infection, long term ART and subtype B’ infection might also predict the occurrence of high-risk LLV.

scholarly journals Factors associated with high-risk low-level viremia leading to virologic failure: 16-year retrospective study of a Chinese antiretroviral therapy cohort

2020 ◽  
Author(s):  
Tong Zhang ◽  
Haibo Ding ◽  
Minghui An ◽  
Xiaonan Wang ◽  
Wen Tian ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
High Risk ◽  
Virologic Failure ◽  
Baseline Viral Load ◽  
Factors Associated ◽  
Low Level ◽  
Subtype B ◽  
High Level ◽  
Hiv 1

Abstract Background: Low level viremia (LLV) often occurs during antiretroviral therapy (ART) against HIV-1. However, whether LLV increases the risk of virologic failure (VF) is controversial because of the non-uniform definitions of LLV and VF. Methods: A long-term first line regimen ART cohort from 2002–2018 from Shenyang, northeast China, was retrospectively studied. All participants were followed up every 3 to 6 months to evaluate the treatment effect. The high-risk LLV subgroups leading to VF (with strict standards) were explored with Cox proportional hazards model and linear mixed-effect model. The association factors of high-risk LLV were further explored using multivariate logistic regression analyses. Results: A total of 2155 HIV-1 infected participants were included; of these, 38.7% showed LLV. Both high level LLV (HLLV) and any other level LLV coupled with high level blip (HLB) showed higher risk of VF (hazards ratios, HRHLLV=5.93, and HRHLB=2.84, p<0.05 respectively). Moreover, HR increased with prolonged duration of LLV. Independent factors associated with high-risk LLV included the zenith baseline viral load (VL) above 6 log copies/ml (aOR=3.49, p=0.002), nadir baseline CD4+T cell counts below 200 cells/mm3 (aOR=1.78, p=0.011), Manchu (aOR=2.03, p=0.003), ART over 60 months (aOR=1.81, p=0.004), AZT+3TC+NVP (aOR=2.26, p<0.001) or DDI-based regimen (aOR=9.96, p=0.002), and subtype B’ infection (aOR=8.22, p=0.001). Conclusions: In case of VF with strict standards, high-risk LLV leading to VF includes VL above 400 copies/ml, occurring at least once. Serious laboratory indicators or advanced stage of infection, long term ART and subtype B’ infection might also predict the occurrence of high-risk LLV.

scholarly journals Factors associated with high-risk low-level viremia leading to virologic failure: 16-year retrospective study of a Chinese antiretroviral therapy cohort

2020 ◽  
Author(s):  
Tong Zhang ◽  
Haibo Ding ◽  
Minghui An ◽  
Xiaonan Wang ◽  
Wen Tian ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
High Risk ◽  
Virologic Failure ◽  
Baseline Viral Load ◽  
Factors Associated ◽  
Low Level ◽  
Subtype B ◽  
High Level ◽  
Hiv 1

Abstract Background: Low level viremia (LLV) often occurs during antiretroviral therapy (ART) against HIV-1. However, whether LLV increases the risk of virologic failure (VF) is controversial because of the non-uniform definitions of LLV and VF. Methods: A long-term first line regimen ART cohort from 2002–2018 from Shenyang, northeast China, was retrospectively studied. All participants were followed up every 3 to 6 months to evaluate the treatment effect. The high-risk LLV subgroups leading to VF (with strict standards) were explored with Cox proportional hazards model and linear mixed-effect model. The association factors of high-risk LLV were further explored using multivariate logistic regression analyses. Results: A total of 2155 HIV-1 infected participants were included; of these, 38.7% showed LLV. Both high level LLV (HLLV) and any other level LLV coupled with high level blip (HLB) showed higher risk of VF (hazards ratios, HRHLLV=5.93, and HRHLB=2.84, p<0.05 respectively). Moreover, HR increased with prolonged duration of LLV. Independent factors associated with high-risk LLV included the zenith baseline viral load (VL) above 6 log copies/ml (aOR=3.49, p=0.002), nadir baseline CD4+T cell counts below 200 cells/mm3 (aOR=1.78, p=0.011), Manchu (aOR=2.03, p=0.003), ART over 60 months (aOR=1.81, p=0.004), AZT+3TC+NVP (aOR=2.26, p<0.001) or DDI-based regimen (aOR=9.96, p=0.002), and subtype B’ infection (aOR=8.22, p=0.001). Conclusions: In case of VF with strict standards, high-risk LLV leading to VF includes VL above 400 copies/ml, occurring at least once. Serious laboratory indicators or advanced stage of infection, long term ART and subtype B’ infection might also predict the occurrence of high-risk LLV.

CASE STUDY: STABILISATION OF A RAPIDLY ERODING POINT USING AN INSITU-FILLED GEOTEXTILE CONTAINER GROYNE FIELD

2017 ◽  
pp. 36
Author(s):  
Bobbie Corbett ◽  
Nicholas Wellwood ◽  
David Shing ◽  
Leslie Angus Jackson
Keyword(s):  
Low Cost ◽  
Low Risk ◽  
Recreational Beach ◽  
High Level

Munna Point is a premiere recreational beach in the Noosa River which has been maintained by regular nourishment for over 20 years. As longevity of each nourishment was less than 6 months, the long-term costs were high and efforts were eventually suspended resulting in loss of the beach. In an effort to reinstate the amenity and provide a more stable beach, a groyne field accompanied by nourishment was proposed. To provide a low-impact, low-risk and low-cost solution, the groynes were designed with a low crest using sand-filled geotextile containers. To achieve the design, containers and scour mattresses were filled in-situ using a dredge, which was an innovative application of a methodology typically adopted for much larger containers. The first 3 groynes have successfully been installed as part of the first stage and 12 months of monitoring subsequently undertaken. The groynes have clearly been effective at extending the longevity of the nourishment and the wider intertidal profile has remained very stable. The beach is now successfully enhancing the amenity of the community and experiencing a high level of usage.

scholarly journals A Robust EMD-Based RVFL Network Fusion Algorithm for Low-Cost GPS/INS Integrated System

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Da Liu ◽  
Shufang Zhang ◽  
Jingbo Zhang
Keyword(s):  
Inertial Sensors ◽  
Low Cost ◽  
Integrated System ◽  
Fusion Algorithm ◽  
Functional Link ◽  
Mode Decomposition ◽  
Error Accumulation ◽  
Lower Complexity ◽  
High Level

Global positioning system (GPS) and inertial navigation system (INS) are commonly combined to overcome disadvantages of each and constitute an integrated system that realizes long-term precision. However, the performance of the integrated system deteriorates on which GPS is unavailable. Especially when low-cost inertial sensors based on the microelectromechanical system (MEMS) are used, performance of the integrated system degrades severely over time. In this study, in order to minimize the adverse impact of high-level stochastic noise from low-cost MEMS sensors, denoising technology based on empirical mode decomposition (EMD) is employed to improve signal quality before navigation solution by which significant improvement of removing noise is achieved. Moreover, a random vector functional link (RVFL) network-based fusion algorithm is presented to estimate and compensate position error during GPS outage such that error accumulation is suppressed quickly when INS is working standalone. Performance of the proposed approach is evaluated by experimental results. It is indicated from comparison that the proposed algorithm takes advantages such as better accuracy and lower complexity and is more robust than the commonly reported methods and is more appropriate for real-time and low-cost application.

scholarly journals High level serum neutralizing antibody against HIV-1 in Chinese long-term non-progressors

2008 ◽  
Vol 52 (4) ◽  
pp. 209-215 ◽  
Author(s):  
Qian Wang ◽  
Hong Shang ◽  
Xiaoxu Han ◽  
Zining Zhang ◽  
Yongjun Jiang ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
High Level ◽  
Hiv 1

scholarly journals Quantification de la Charge Virale et tests de résistance du VIH-1 aux ARV à partir d’échantillons DBS (Dried Blood Spots) chez des patients Guinéens sous traitement antirétroviral

2015 ◽  
Vol 4 (1) ◽  
Author(s):  
Nestor Bangoura ◽  
Abou A.M. Diouara ◽  
Mohamed Cissé ◽  
Halimatou D. Ndiaye ◽  
Souleymame Mboup ◽  
...  
Keyword(s):  
Viral Load ◽  
Virological Failure ◽  
Dried Blood Spots ◽  
Resistance Rate ◽  
Reference Laboratory ◽  
Blood Spots ◽  
Traitement Antirétroviral ◽  
Virological Monitoring ◽  
Hiv 1 ◽  
Charge Virale

Problématique: Comme dans plusieurs pays du Sud, le suivi virologique des patients sous traitement antirétroviral (TARV) en Guinée est timide voire inexistant dans certaines localités. Le but de cette étude était d’évaluer la faisabilité technique et logistique de l’utilisation des DBS dans les tests de charge virale (CV) et de génotypage.Méthode: De septembre à octobre 2010, les DBS ont été préparés à partir de prélèvements sanguins de patients adultes sous TARV. Le délai d’envoi des échantillons au laboratoire de référence était de 30 jours maximum après le prélèvement et se faisait à température ambiante. La CV a été quantifiée et les échantillons de patients en échec virologique (CV ≥ 3 log10 copies/mL) ont été génotypés selon le protocole de l’ANRS. L’algorithme de Stanford version 6.0.8 a été utilisé pour l’analyse et l’interprétation des mutations de résistance.Résultats: Parmi les 136 patients inclus, 129 et 7 étaient respectivement sous première et deuxième ligne de traitement avec une médiane de suivi de 35 mois [IQR: 6-108]. L’échec virologique a été noté chez 33 patients. Parmi eux, 84.8% (n = 28/33) ont bénéficié d’ungénotypage. Le taux de résistance global était de 14% (n = 19/136). Le CRF02_AG était le sous type viral le plus prévalent (82%; n = 23).Conclusion: En plus de montrer la faisabilité technique et logistique des tests de CV et de génotypage à partir des DBS, ces résultats montrent l’intérêt de leurs utilisations dans le suivi virologique des patients sous TARV. Cette étude a permis également de documenter l’échec virologique, la résistance aux ARV et la diversité génétique du VIH-1 en Guinée.Mots clés: VIH-1, Résistance aux ARV, DBS (Dried Blood Spots), Guinée Conakry, Génotypage,Charge Virale. Quantification of Viral load and resistance tests of HIV-1 to ARVs from dried blood spotssamples in Guinean patients undergoing antiretroviral treatment.Problem: As in several countries of the South, the virological monitoring of patients undergoing antiretroviral treatment (ARVT) in Guinea is low or non-existent in some locations. The aim ofthis study was to assess the technical and logistical feasibility of the use of (dried blood spots) DBSs in viral load (VL) and genotyping tests.Method: From September 2010 to October 2010, DBS were prepared from blood samples of adult patients under ARVT. The samples had to be sent to the reference laboratory within 30 days after the sample had been done at ambient temperature. The VL was quantified and the samples of patients with virological failure (CV ≥ 3 log10 copies/mL) were genotyped according to the ANRS protocol. The Stanford algorithm, version 6.0.8, was used to analyse and interpret the resistance mutations.Results: Amongst the 136 included patients, 129 and 7 were under first and second line treatment respectively, and monitored for an average of 35 months [IQR: 6-108]. Virological failure was noticed among 33 patients. Among them, 84.8% (n = 28/33) benefited from genotyping. The global resistance rate was 14% (n = 19/136). CRF02_AG was the most prevalent viral subtype (82%; n = 23).Conclusion: In addition to demonstrating the technical and logistic feasibility of VL and genotyping tests from DBSs, these results show the relevance of their use in the virological monitoring of patients under ARVT. Also, this study made it possible to provide informationon virological failure, ARV resistance and the HIV-1 genetic diversity in Guinea.

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