Accurate HIV viral load measurement in primary health care settings using the cobas® plasma separation card

Viral load suppression among HIV-positive adult patients on the first-line antiretroviral treatment regimen in health facilities in the City of Ekurhuleni, Gauteng province, South Africa

Introduction

the Human Immunodeficiency Virus (HIV) remains a global health concern, with South Africa among the hardest hit countries. Viral suppression in HIV patients is a positive treatment outcome when monitoring progress and using antiretrovirals (ART). Despite the Joint United Nations Programme on HIV/AIDS (UNAIDS) 95-95-95 strategy which focuses on monitoring viral suppression, unsuppressed viral loads keep persisting because of several factors. The study sought to determine viral load suppression and contributing factors among adult patients on first-line ART in Ekurhuleni District, South Africa.

Methods

the study reviewed 379 patient files of adult patients on first-line ART between April and June 2018. Standardized tools were used to collect sociodemographic and clinical data. Descriptive data was analyzed using frequency tabulations and percentages, and multivariable logistic regression was used to identify factors associated with viral load suppression.

Results

the study included 379 patient records. Mean age; DS of 38.9 years with standard deviation at 10.1. The prevalence of viral load suppression at 12 months was 75.2% (n=285). Female participants had higher suppression rates 77.7% (n=188) than males 70.8% (n=97), received pre-ART counseling 73.1% (n=277) as well as no history of tuberculosis 92.4% (n=350). Being female with (aOR=7.29, 95% CI: 1.02 - 52.26; p=0.04) and having completed a six-month viral load assessment (aOR=1.85, 95% CI: 1.00 - 3.41; p=0.04) were independently associated with higher odds of having a suppressed viral load. However, being referred for adherence (aOR=0.61, 95% CI: 0.37 - 0.99; p=0.05) and having a previous history of ART exposure (aOR=0.29, 95% CI 0.10 - 0.77; p=0.01) were independently associated with lower odds of having a suppressed viral load.

Conclusion

a higher suppression rate among female patients, suggests that more targeted interventions should be facilitated among HIV-positive male patients linkage to care and initiated on ART. Exposing the patient to a few enhanced support programs hinders progress toward reducing nonadherence, lack of awareness, and inadequate knowledge about the benefits of achieving viral suppression among people living with HIV.

Acceptability and Feasibility of the Plasma Separation Card for an Integrated Model of Care for HBV and HCV Screening Among People Attending HIV Clinics in Cameroon and Uganda

BACKGROUND

Sub-Saharan African countries have a high burden of viral hepatitis and poor access to screening and care. The aim of this study was to evaluate the feasibility and acceptability of using the plasma separation card (PSC) for viral hepatitis B and C screening among people living with HIV (PLHIV) in Cameroon and Uganda.

METHODS

This is a cross-sectional study carried out between 05/2021 and 03/2023 including 192 PLHIV in Cameroon (n = 104) and Uganda (n = 88). Basic sociodemographic variables and whole blood samples were collected. Adequate filling with blood of PSCs was used to determine feasibility together with participant responses to questions on acceptability. A logistic regression model was carried out to assess the relationship between PSC acceptability and factors of interest.

RESULTS

70% of participants reported PSC as an acceptable viral hepatitis screening tool, and it was significantly more accepted in Uganda than Cameroon (100% vs. 43.2%, p < 0.001). Similarly, 75% of PSCs had at least one spot sample filled and were viable for analysis, 99% were correctly filled in Uganda and 53.4% in Cameroon. Reported ease of method performance (aOR: 24.77 95% CI 2.97-206.42, p = 0.003) and reduced collection time (aOR: 3.73 95% CI 1.26-11.04, p = 0.017) were associated with greater odds of PSC acceptance. HBsAg + and anti-HCV + prevalence were 11.1% and 1.0%, respectively.

CONCLUSIONS

In spite of country differences, overall, the PSC was reported as a feasible and acceptable viral hepatitis testing method. Acceptability and feasibility of the method must be explored in heterogeneous target communities and qualitative research to better understand country-specific barriers and facilitators should be carried out.

Assessment of the performance of the plasma separation card for HIV-1 viral load monitoring in South Africa

Scaling up of newer innovations that address the limitations of the dried blood spot and the logistics of plasma monitoring is needed. We employed a multi-site, cross-sectional assessment of the plasma separation card (PSC) on blood specimens collected from all consenting adults, assenting young and pediatric patients living with HIV from 10 primary healthcare clinics in South Africa. Venous blood for EDTA-plasma samples was collected and analyzed according to the standard of care assay, while collected capillary blood for the PSC samples was analyzed using the Roche COBAS AmpliPrep/Cobas TaqMan (CAP/CTM) HIV-1 Test at the National Reference laboratories. McNemar tests assessed the differences in concordance between the centrifuged plasma and dried plasma spots. The usability of PSC by blood spotting, PSC preparation, and pre-analytical work was assessed by collecting seven-point Likert-scale data from healthcare and laboratory workers. We enrolled 538 patients, mostly adults [n = 515, 95.7% (95% CI: 93.7%-97.1%)] and females [n = 322, 64.2% (95% CI: 60.0%-68.1%)]. Overall, 536 paired samples were collected using both PSC- and EDTA-plasma diagnostics, and 502 paired PSC- and EDTA-plasma samples assessed. Concordance between the paired samples was obtained for 446 samples. Analysis of these 446 paired samples at 1,000 copies per milliliter threshold yielded an overall sensitivity of 87.5% [95% CI: 73.2%-95.8%] and specificity of 99.3% [95% CI: 97.9%-99.8%]. Laboratory staff reported technical difficulties in most tasks. The usability of the PSC by healthcare workers was favorable. For policymakers to consider PSC scale-up for viral load monitoring, technical challenges around using PSC at the clinic and laboratory level need to be addressed.

IMPORTANCE

Findings from this manuscript emphasize the reliability of the plasma separation card (PSC), a novel diagnostic method that can be implemented in healthcare facilities in resource-constrained settings. The agreement of the PSC with the standard of care EDTA plasma for viral load monitoring is high. Since the findings showed that these tests were highly specific, we recommend a scale-up of PSC in South Africa for diagnosis of treatment failure.

Performance of two plasma separation devices for HIV-1 viral load measurement in primary healthcare settings

IMPORTANCE

Burnett and HemaSpot are two novel technologies that allow whole blood collection and plasma separation and stabilization at room temperature without the need of additional equipment. Hence, these devices are potential alternatives to fresh plasma as a suitable specimen for viral load scale-up to monitor antiretroviral therapy in resource-limited settings.

Performances of Dried Blood Spots and Point-of-Care Devices to Identify Virological Failure in HIV-Infected Patients: A Systematic Review and Meta-Analysis

To broaden access to HIV viral load monitoring (VLM), the use of blood samples from dried blood spots (DBS) or point-of-care (POC) devices, could be of great help in settings where plasma is not easily accessible. The variety of assays available makes the choice complex. This systematic review and meta-analysis aims to estimate the sensitivity and specificity of DBS and POC devices to identify patients in virological failure using World Health Organization (WHO) recommendations (viral load ≥1000 copies/mL), compared with plasma, for the assays currently available. Four databases were searched for articles, and two reviewers independently identified articles reporting sensitivity and specificity of DBS and/or POC to identify patients in virological failure. We excluded articles that used other thresholds as well as articles with a total number of participants below 50 to avoid reporting bias. Heterogeneity and factors associated with assays' performances were assessed by I² statistics and metaregression. The protocol of this review follows the PRISMA guidelines. Out of 941 articles, 47 were included: 32 DBS evaluations and 16 POC evaluations. Overall, when using DBS, the Abbott RT HIV-1, Roche CAP-CTM, NucliSENS BioMerieux and Aptima assays presented sensitivity and specificity exceeding 85%, but reported results were highly heterogeneous. Factors associated with better performances were high volume of blood and the use of the same assay for DBS and plasma VLM. Regarding the POC devices, SAMBA I, SAMBA II, and GeneXpert devices presented high sensitivity and specificity exceeding 90%, with less heterogeneity. DBS is suitable VLM, but performances can vary greatly depending on the protocols, and should be performed in trained centers. POC is suitable for VLM with less risk of heterogeneity but is more intensive in costs and logistics.

Direct Processing and Storage of Cell-Free Plasma Using Dried Plasma Spot Cards

Plasma separation cards represent a viable approach for expanding testing capabilities away from clinical settings by generating cell-free plasma with minimal user intervention. These devices typically comprise a basic structure of the plasma separation membrane, unconstrained porous collection pad, and utilize either (i) lateral or (ii) vertical fluidic pathways for separating plasma. Unfortunately, these configurations are highly susceptible to (i) inconsistent sampling volume due to differences in the patient hematocrit or (ii) severe contamination due to leakage of red blood cells or release of hemoglobin (i.e., hemolysis). Herein, we combine the enhanced sampling of our previously reported patterned dried blood spot cards with an assembly of porous separation materials to produce a patterned dried plasma spot card for direct processing and storage of cell-free plasma. Linking both vertical separation and lateral distribution of plasma yields discrete plasma collection zones that are spatially protected from potential contamination due to hemolysis and an inlet zone enriched with blood cells for additional testing. We evaluate the versatility of this card by quantitation of three classes of analytes and techniques including (i) the soluble transferrin receptor by enzyme-linked immunosorbent assay, (ii) potassium by inductively coupled plasma atomic emission spectroscopy, and (iii) 18S rRNA by reverse transcriptase quantitative polymerase chain reaction. We achieve quantitative recovery of each class of analyte with no statistically significant difference between dried and liquid reference samples. We anticipate that this sampling approach can be applied broadly to improve access to critical blood testing in resource-limited settings or at the point-of-care.

Evaluation of a Quantitative Taqman Real-Time PCR Assay to Measure Proviral load from Human Immunodeficiency Virus Type 1 individuals

Human Immunodeficiency Virus (HIV) is a virus belonging to the family Retroviridae. HIV – 1 is found to be predominant in India and many parts of Africa. The intention of this study was to quantify the HIV Proviral Deoxyribonucleic Acid (DNA) from newly infected HIV-1 individuals. Fifty patients who were tested positive for HIV were included in this study. Proviral Ribo Nucleic Acid (RNA) was extracted by QIAmp® RNA Mini Kit (QIAGEN, Germany) method. Complementary Deoxyribo Nucleic Acid (cDNA) was synthesized by using Invitrogen Superscript III cDNA synthesis Kit (USA). This cDNA was subjected to Polymerase Chain Reaction (PCR) and Gene cloning by transformation method. The quantification of Real time PCR was done by Applied Bio-System (ABI)-Prism 7700. A linear standard curve was obtained 10 copies to 106 copies per reaction. The assay had good analytic sensitivity and linear dynamic range greater than 6 logs. From the results obtained in this study, It was concluded that Taqman Real-Time PCR Assay plays a major role in monitoring the HIV infected patients in routine diagnostics and clinical practice.

Stability of HIV-1 Nucleic Acids in cobas Plasma Separation Card for Viral Load Measurement

OBJECTIVES

Our study aimed to evaluate the stability of human immunodeficiency virus 1 (HIV-1) RNA on cobas plasma separation card (PSC) specimens for viral load (VL) testing after being exposed to varied temperatures and storage times.

METHODS

For this purpose, venous PSC specimens were collected and stored at 25ºC to 42ºC for a period of up to 28 days. Plasma VL at baseline was used as reference, against which PSC VL was compared at different time points.

RESULTS

From the 30 patients included in the study, 600 PSC and 30 fresh plasma specimens were obtained. Plasma VL at baseline was fewer than 1,000 copies/mL in 16 patients, and 99.4% of PSCs from these patients yielded nonquantifiable VL at all temperature ranges and time points. During the study period, minor variation of VL was observed in PSCs obtained from 13 patients with plasma VL fewer than 1,000 copies/mL at baseline. For the patient with plasma VL at 1,000 copies/mL, the PSC VL varied from undetectable to 1,670 copies/mL.

CONCLUSIONS

Our results show minor variation of VL in PSC specimens in the study conditions. HIV RNA is stable in PSCs exposed to high temperatures for up to 28 days.

Managing laboratory waste from HIV-related molecular testing: Lessons learned from African countries

Waste generated from HIV viral load (VL) testing contains potentially hazardous guanidinium thiocyanate (GTC). GTC is toxic to humans and can pollute waters and harm aquatic life if not disposed of appropriately. We assessed gaps in waste management (WM) policies, regulations and practices through a self-assessment scorecard and an online survey questionnaire among 11 African countries participating in a laboratory systems strengthening community of practice and receiving technical assistance to scale-up VL testing. We identified solutions from national stakeholders, technical agencies, and manufacturers to inform interventions for improving WM. Nine of 11 countries did not have WM policies/guidelines in place. Most Countries reported disposing liquid chemical waste into the sewer. Nine countries prioritised the development of policies as a multi-sectoral approach in the short term. High-temperature incineration through cement factory kilns was identified as an effective, inexpensive and high-capacity disposal option for GTC-containing waste in the short term. A long-term consideration with funding from governments and donors were infrastructural investments for conventional high-temperature incineration where cement factory kilns are unavailable/inaccessible. Adequate WM of GTC-containing waste through available funding could provide the necessary impetus to establish comprehensive WM systems addressing all types of healthcare waste through a multisectoral approach.