The performance of using dried blood spot specimens for HIV-1 viral load testing: A systematic review and meta-analysis

Comparison of dried blood spot (DBS) and plasma HIV-1 viral load measurements using Roche COBAS AmpliPrep/COBAS TaqMan assay, Northwest Ethiopia

INTRODUCTION

Quantitative determination of HIV-1 viral load measurements using plasma samples has been widely applicable for prompt monitoring at baseline and following initiation of highly active antiretroviral therapy (HAART). However, improper mixing of whole blood with anticoagulants during plasma sample processing, as well as limited access to specialized health facilities might hinder HIV diagnosis services. Considering its higher stability and increased accessibility in areas with poor laboratory settings, the dried blood spot (DBS) sample might be a suitable alternative approach for periodic monitoring of HIV-1 viral load measurements. Thus, in this study, we aimed to compare the quantitative determination of HIV-1 RNA levels using plasma and DBS samples among people living with HIV in Northwest Ethiopia.

METHODS

An institutional-based analytical cross-sectional study was conducted from March to July 2020 using 48 paired plasma and DBS samples among people living with HIV at the HIV Treatment Center, Northwest Ethiopia. A total of four milliliters of venous blood was collected to harvest plasma and for DBS sample preparation. The HIV-1 RNA extraction, amplification, and quantification were performed using the Roche COBAS AmpliPrep/COBAS TaqMan version 2.0 assay. Data were managed and analyzed using SPSS version 26 software. Mean HIV-1 viral load measurements as well as the associations between plasma and DBS sample measurements were computed using a paired sample t-test and Pearson's correlation statistical tests, respectively. In addition, the level of agreement and the presence of proportional bias between sample measurements were performed using the Bland-Altman plot and linear regression models, respectively. A p-value of ≤ 0.05 with a 95% confidence interval was considered statistically significant.

RESULTS

Among 48 people living with HIV, more than half (64.6%) of them were females. The minimum and maximum age of the study participants was 12 and 58 years, respectively. The mean difference with standard deviation (SD) of sample measurements (DBS minus plasma) HIV-1 viral load was 0.66 ± 0.70 log copies/mL. In the current study, a strong association with a significant linear correlation (r = 0.796) (p < 0.001) was obtained from Pearson's correlation analysis among HIV-1 viral load measurements between DBS and plasma samples. Moreover, the Bland-Altman plot also depicted a high level of agreement between the sample measurements.

CONCLUSIONS

The findings of the current study suggested that DBS samples could be considered as an alternative approach for periodic monitoring of HIV-1 viral loads to scale-up the HIV diagnosis and treatment coverage, particularly in areas with limited laboratory settings due to minimal invasive blood collection, higher stability at room temperature or ease of transportation, and decentralized sample collection approaches.

Implementation of pooled testing to increase access to routine viral load monitoring for people living with HIV on antiretroviral therapy

For the 30 million people living with HIV on antiretroviral therapy, routine viral load testing is recommended to monitor treatment effectiveness. However, only an estimated 77% of eligible people accessed viral load testing in 2022, due to barriers including the high costs of tests. Here we assessed implementation of pooled testing to increase viral load testing efficiency at a reference laboratory in Cameroon. Plasma specimens were tested in pools of three using the Abbott RealTime HIV-1 Viral Load assay. For pools with HIV-1 detected, each specimen was then tested and reported individually; for the negative pools, the pooled result was reported with no further testing. From July to December 2023, results for 12,396 specimens tested in pools were produced using 6,797 assays, or 0.55 assays per result, with 3.6% (449) reported as unsuppressed (> 1,000 copies/mL), enabling an additional 5,409 people (+ 80%) to have test results. When testing pools of three, the limit of detection per specimen increases from < 40 copies/mL to < 120 copies/mL, with only an estimated 0.01% of specimens with results of ≥ 1,001 copies/mL (unsuppressed) having results misclassified as suppressed. These results demonstrate that pooled testing can be an efficient and accurate approach to increase access to viral load monitoring.

Heavily treatment-experienced patients with HIV: are new mechanisms of action enough?

Antiretroviral (ARV) drug resistance poses a threat to ending the HIV epidemic. As the rates of integrase resistance continue to increase globally, the availability of options for HIV treatment becomes limited. Heavily treatment-experienced (HTE) people with HIV (PWH) are limited to two or fewer available fully active ARV classes and are more likely to have an AIDS-defining event. Appropriate identification and management of HTE PWH is crucial to improving patient outcomes and reducing the future spread of drug-resistant HIV. As treatment options become more limited owing to drug resistance, the availability of more potent drugs with a marked increase in virologic suppression is needed in the current ART era. The purpose of this narrative review is to review the identification of HTE PWH, novel mechanisms of resistance, and management of HTE PWH in resource-rich and resource-limited settings using novel ARVs and combination ART.

Performance of patient-collected dried blood specimens for HIV-1 viral load testing in South Africa

OBJECTIVE

Evaluate the clinical utility of patient-collected dried blood spots (DBS) in measuring HIV-1 viral load (VL) for monitoring antiretroviral therapy (ART) compared to provider-collected DBS and blood plasma.

DESIGN

In a randomized trial of community-based delivery of ART in South Africa, we assessed performance of: DBS specimens compared to plasma, and participant-collected vs. staff-collected DBS specimens, to measure HIV-1 VL.

METHODS

The bioMérieux NucliSENS EasyQ HIV-1 v2.0 assay was used for VL measurement. From October 2017 to November 2019, we collected 996 pairs of plasma/DBS specimens from 760 participants and 315 pairs of staff-/participant-collected DBS cards from 261 participants. We assessed DBS test sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) using the WHO failure threshold of 1000 copies/ml. Log-transformed VL was compared using concordance correlation coefficients (CCC) and mean differences from linear mixed models.

RESULTS

In a population with 13% detectable VL, DBS VL compared with plasma VL had 91% [95% confidence interval (CI): 86-95] sensitivity, 99% (98-100) specificity, 94% (90-98) PPV, and 99% (98-99) NPV. We observed high agreement between staff-collected DBS VL and plasma VL (CCC: 0.94), and between participant-collected DBS VL and plasma VL (CCC: 0.92). We did not observe a statistically significant difference between participant- and staff-collected DBS VL and correlation was very high (CCC: 0.97).

CONCLUSIONS

VL results from participant-collected DBS are clinically comparable with those collected by clinical staff and using blood plasma. Self-collected DBS has potential for use for ART monitoring outside the clinic.

Challenges and Opportunities with at-Home Blood Collection for HIV-1 Viral Load Monitoring among Sexual Minoritized Men who use Stimulants

Sexually minoritized men (SMM) with HIV who use stimulants experience difficulties achieving and maintaining an undetectable viral load (VL). Home-based VL monitoring could augment HIV care by supporting interim, early identification of detectable VL. We describe implementation challenges associated with a home-collection device for laboratory-based VL testing among SMM with HIV who use stimulants. From March-May 2022, cisgender SMM with HIV reporting moderate-to-severe stimulant use disorder and suboptimal (< 90%) past-month antiretroviral therapy (ART) adherence were recruited via a consent-to-contact participant registry. Eligible men completed teleconference-based informed consent and were mailed a HemaSpot-HD blood collection device (volume capacity 160 µL; lower limit of detection 839 copies/mL) with detailed instructions for home blood self-collection and return shipment. Implementation process measures included estimated blood volume and VL quantification. Among 24 participants, 21 (88%) returned specimens with a median duration of 23 days (range: 10-71 days) between sending devices to participants and receiving specimens. Of these, 13/21 (62%) included enough blood (≥ 40 µL) for confidence in detectable/undetectable results; 10/13 (77%) had detectable VL, with 4/10 (40%) were quantifiable at ≥ 839 copies/mL. The remaining 8/21 had low blood volume (< 40 µL), but 3/8 (38%) still had detectable VL, with 1/3 (33%) quantifiable at ≥ 839 copies/mL. Home blood collection of ≥ 40 µL using HemaSpot-HD was feasible among this high-priority population, with > 50% having a VL detected. However, interim VL monitoring using HemaSpot-HD among those experiencing difficulties with ART adherence may be strengthened by building rapport via teleconferencing and providing detailed instructions to achieve adequate sample volume.

Supporting treatment adherence for resilience and thriving (START): protocol for a mHealth randomized controlled trial

BACKGROUND

Although behavioral interventions show some promise for reducing stimulant use and achieving durable viral suppression in sexual minority men (SMM) with HIV, scalable mHealth applications are needed to optimize their reach and cost-effectiveness.

METHODS

Supporting Treatment Adherence for Resilience and Thriving (START) is a randomized controlled trial (RCT) testing the efficacy and cost-effectiveness of a mHealth application that integrates evidence-based positive affect regulation skills with self-monitoring of adherence and mood. The primary outcome is detectable HIV viral load (i.e., > 300 copies/mL) from self-collected dried blood spot (DBS) specimens at 6 months. Secondary outcomes include detectable DBS viral load at 12 months, self-reported stimulant use severity, anti-retroviral therapy (ART) adherence, and positive affect over 12 months. A national sample of up to 250 SMM with HIV who screen positive for stimulant use disorder and reporting suboptimal ART adherence is being recruited via social networking applications through April of 2024. After providing informed consent, participants complete a run-in period (i.e., waiting period) including two baseline assessments with self-report measures and a self-collected DBS sample. Those who complete the run-in period are randomized to either the START mHealth application or access to a website with referrals to HIV care and substance use disorder treatment resources. Participants provide DBS samples at baseline, 6, and 12 months to measure HIV viral load as well as complete self-report measures for secondary outcomes at quarterly follow-up assessments over 12 months.

DISCUSSION

To date, we have paid $117,500 to advertise START on social networking applications and reached 1,970 eligible participants ($59.77 per eligible participant). Although we identified this large national sample of potentially eligible SMM with HIV who screen positive for a stimulant use disorder and report suboptimal ART adherence, only one-in-four have enrolled in the RCT. The run-in period has proven to be crucial for maintaining scientific rigor and reproducibility of this RCT, such that only half of consented participants complete the required study enrollment activities and attended a randomization visit. Taken together, findings will guide adequate resource allocation to achieve randomization targets in future mHealth research SMM with HIV who use stimulants.

TRIAL REGISTRATION

This protocol was registered on clinicaltrials.gov (NCT05140876) on December 2, 2021.

Validity of dried blood spot testing for sexually transmitted and blood-borne infections: A narrative systematic review

Testing for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) using dried blood spot (DBS) specimens has been an integral part of bio-behavioural surveillance in Canada for almost two decades, though less is known regarding the use of DBS in surveillance of other sexually transmitted and blood-borne infections (STBBI). A systematic review was conducted using a peer-reviewed search strategy to assess the current evidence regarding the validity of STBBI testing using DBS specimens. Eligibility criteria included studies reporting use of DBS specimens for STBBI testing with either commercially available or "in-house" tests in populations 15 years of age or older. Studies reporting a measure of validity such as sensitivity, specificity, positive and negative predictive values were eligible for inclusion. Quality of studies and risk of bias were assessed using the QUADAS-2 tool. A total of 7,132 records were identified. Of these, 174 met the criteria for inclusion. Among the studies that reported validity measures, a substantial proportion demonstrated high sensitivity (≥90%) in 62.5% of cases (N = 334/534 sensitivity measurements), and high specificity (≥90%) was observed in 84.9% of instances (N = 383/451 specificity measurements). However, the quality of the studies varied greatly. Our findings support the validity of the use of DBS specimens in STBBI testing where sufficient evidence was available, but validity is highly dependent on thorough method development and validation.

Disparities in Telehealth Use in HIV Care During the COVID-19 Pandemic: Study Findings from South Carolina

Background: Telehealth was adopted to maintain HIV care continuity during the COVID-19 pandemic; however, its use was unequally distributed. This study examined variation in HIV care visit patterns and whether telehealth use was associated with viral suppression. Methods: Electronic health record (EHR) data from a large HIV clinic in South Carolina was analyzed using multivariable logistic regression to characterize variation in telehealth use, having a viral load (VL) test, and viral suppression in 2022. Results: EHR data from 2,375 people living with HIV (PWH) between March 2021 and March 2023 showed telehealth use among 4.8% of PWH. PWH who are 50+ years and non-Hispanic Black had lower odds of telehealth use (odds ratio [OR] 0.59, 95% confidence interval [CI 0.40-0.86]; OR 0.58, 95% CI [0.37-0.92] respectively). Telehealth use was not associated with viral suppression and VL testing. Conclusion: Telehealth disparities in HIV care affected older and non-Hispanic Black PWH, requiring tailored strategies to promote telehealth among them.

Which Features of Telehealth in HIV Care Are Most Important? A Mixed-Methods Study With HIV Care Providers and People Living With HIV in South Carolina

ABSTRACT

Telehealth was rapidly implemented in HIV care during COVID-19 yet remains understudied. To assess the importance of telehealth features, we conducted a mixed-methods study with HIV care providers and people living with HIV. Qualitative interviews and ranking exercises revealed heterogeneity in preference-relevant features of telehealth in HIV care.

Revolutionizing HIV-1 Viral Load Monitoring in India: The Potential of Dried Blood Spot Analysis for Expanding Access and Improving Care

India continues to grapple with a significant burden of HIV infections. Despite notable progress in prevention and treatment efforts, multiple challenges, such as high-risk populations, inadequate testing facilities, and limited access to healthcare in remote areas, persist. Though the Government of India offers HIV-1 plasma viral load testing at various medical centers, aiding treatment decisions and monitoring antiretroviral therapy effectiveness, enhancing care for individuals living with HIV under the National AIDS Control Program (NACP), the nation's large population and diverse demographics further complicate its outreach and response. Hence, strategic interventions and alternative methods of testing remain crucial to curbing HIV transmission and improving the quality of life for those affected. Dried blood spot (DBS) sampling has emerged as a convenient and cost-effective alternative for HIV-1 viral load testing, revolutionizing the landscape of diagnostic and monitoring strategies for HIV infection. Though the plasma-based viral load remains the gold standard for monitoring HIV-1, DBS-based HIV-1 viral load testing holds immense promise for improving access to care, particularly in resource-limited settings where traditional plasma-based methods may be logistically challenging. DBS entails the collection of a small volume of blood onto filter paper, followed by drying and storage. This approach offers numerous advantages, including simplified sample collection, transportation, and storage, reducing the need for cold-chain logistics. Recent studies have demonstrated the feasibility and accuracy of DBS-based HIV-1 viral load testing, revealing a strong correlation between DBS and plasma measurements. Its implementation can enhance the early detection of treatment failure, guide therapeutic decisions, and ultimately contribute to better clinical outcomes for HIV-infected individuals. Hence, this review explores the principles, advancements, feasibility, and implications of DBS-based HIV-1 viral load testing.

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.

Quantifying neutralising antibody responses against SARS-CoV-2 in dried blood spots (DBS) and paired sera

The ongoing SARS-CoV-2 pandemic was initially managed by non-pharmaceutical interventions such as diagnostic testing, isolation of positive cases, physical distancing and lockdowns. The advent of vaccines has provided crucial protection against SARS-CoV-2. Neutralising antibody (nAb) responses are a key correlate of protection, and therefore measuring nAb responses is essential for monitoring vaccine efficacy. Fingerstick dried blood spots (DBS) are ideal for use in large-scale sero-surveillance because they are inexpensive, offer the option of self-collection and can be transported and stored at ambient temperatures. Such advantages also make DBS appealing to use in resource-limited settings and in potential future pandemics. In this study, nAb responses in sera, venous blood and fingerstick blood stored on filter paper were measured. Samples were collected from SARS-CoV-2 acutely infected individuals, SARS-CoV-2 convalescent individuals and SARS-CoV-2 vaccinated individuals. Good agreement was observed between the nAb responses measured in eluted DBS and paired sera. Stability of nAb responses was also observed in sera stored on filter paper at room temperature for 28 days. Overall, this study provides support for the use of filter paper as a viable sample collection method to study nAb responses.

Dried Blood Spots-A Platform for Therapeutic Drug Monitoring (TDM) and Drug/Disease Response Monitoring (DRM)

This review provides an overview on the current applications of dried blood spots (DBS) as matrices for therapeutic drug (TDM) and drug or disease response monitoring (DRM). Compared with conventional methods using plasma/serum, DBS offers several advantages, including minimally invasiveness, a small blood volume requirement, reduced biohazardous risk, and improved sample stability. Numerous assays utilising DBS for TDM have been reported in the literature over the past decade, covering a wide range of therapeutic drugs. Several factors can affect the accuracy and reliability of the DBS sampling method, including haematocrit (HCT), blood volume, sampling paper and chromatographic effects. It is crucial to evaluate the correlation between DBS concentrations and conventional plasma/serum concentrations, as the latter has traditionally been used for clinical decision. The feasibility of using DBS sampling method as an option for home-based TDM is also discussed. Furthermore, DBS has also been used as a matrix for monitoring the drug or disease responses (DRM) through various approaches such as genotyping, viral load measurement, assessment of inflammatory factors, and more recently, metabolic profiling. Although this research is still in the development stage, advancements in technology are expected to lead to the identification of surrogate biomarkers for drug treatment in DBS and a better understanding of the correlation between DBS drug levels and drug responses. This will make DBS a valuable matrix for TDM and DRM, facilitating the achievement of pharmacokinetic and pharmacodynamic correlations and enabling personalised therapy.

The risk of sexual transmission of HIV in individuals with low-level HIV viraemia: a systematic review

BACKGROUND

The risk of sexual transmission of HIV from individuals with low-level HIV viraemia receiving antiretroviral therapy (ART) has important public health implications, especially in resource-limited settings that use alternatives to plasma-based viral load testing. This Article summarises the evidence related to sexual transmission of HIV at varying HIV viral load levels to inform messaging for people living with HIV, their partners, their health-care providers, and the wider public.

METHODS

We conducted a systematic review and searched PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, Embase, Conference Proceedings Citation Index-Science, and WHO Global Index Medicus, for work published from Jan 1, 2010 to Nov 17, 2022. Studies were included if they pertained to sexual transmission between serodiscordant couples at various levels of viraemia, the science behind undetectable=untransmittable, or the public health impact of low-level viraemia. Studies were excluded if they did not specify viral load thresholds or a definition for low-level viraemia or did not provide quantitative viral load information for transmission outcomes. Reviews, non-research letters, commentaries, and editorials were excluded. Risk of bias was evaluated using the ROBINS-I framework. Data were extracted and summarised with a focus on HIV sexual transmission at varying HIV viral loads.

FINDINGS

244 studies were identified and eight were included in the analysis, comprising 7762 serodiscordant couples across 25 countries. The certainty of evidence was moderate; the risk of bias was low. Three studies showed no HIV transmission when the partner living with HIV had a viral load less than 200 copies per mL. Across the remaining four prospective studies, there were 323 transmission events; none were in patients considered stably suppressed on ART. Among all studies there were two cases of transmission when the index patient's (ie, patient with previously diagnosed HIV infection) most recent viral load was less than 1000 copies per mL. However, interpretation of both cases was complicated by long intervals (ie, 50 days and 53 days) between the transmission date and the most recent index viral load result.

INTERPRETATION

There is almost zero risk of sexual transmission of HIV with viral loads of less than 1000 copies per mL. These data provide a powerful opportunity to destigmatise HIV and promote adherence to ART through dissemination of this positive public health message. These findings can also promote access to viral load testing in resource-limited settings for all people living with HIV by facilitating uptake of alternative sample types and technologies.

FUNDING

Bill & Melinda Gates Foundation.

Biological Fluid Microsampling for Therapeutic Drug Monitoring: A Narrative Review

Therapeutic drug monitoring (TDM) is a specialized area of laboratory medicine which involves the measurement of drug concentrations in biological fluids with the aim of optimizing efficacy and reducing side effects, possibly modifying the drug dose to keep the plasma concentration within the therapeutic range. Plasma and/or whole blood, usually obtained by venipuncture, are the "gold standard" matrices for TDM. Microsampling, commonly used for newborn screening, could also be a convenient alternative to traditional sampling techniques for pharmacokinetics (PK) studies and TDM, helping to overcome practical problems and offering less invasive options to patients. Although technical limitations have hampered the use of microsampling in these fields, innovative techniques such as 3-D dried blood spheroids, volumetric absorptive microsampling (VAMS), dried plasma spots (DPS), and various microfluidic devices (MDS) can now offer reliable alternatives to traditional samples. The application of microsampling in routine clinical pharmacology is also hampered by the need for instrumentation capable of quantifying analytes in small volumes with sufficient sensitivity. The combination of microsampling with high-sensitivity analytical techniques, such as liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), is particularly effective in ensuring high accuracy and sensitivity from very small sample volumes. This manuscript provides a critical review of the currently available microsampling devices for both whole blood and other biological fluids, such as plasma, urine, breast milk, and saliva. The purpose is to provide useful information in the scientific community to laboratory personnel, clinicians, and researchers interested in implementing the use of microsampling in their routine clinical practice.

The plasma separation card as a novel solution for enhancing central laboratory capability for HIV-1 viral load monitoring in limited-access settings

Measurement of HIV-1 viral load (VL) is essential for monitoring antiretroviral treatment (ART) efficacy. The preferred specimen type for VL is plasma, but in remote settings where collection and preservation of plasma many not be possible, dried blood spots (DBS) are often used instead. A new specimen collection matrix, the cobas plasma separation card (PSC, Roche Diagnostics Solutions), enables specimen preparation from a finger prick or venous blood, using a multi-layer absorption and filtration design that results in a specimen similar to dried plasma. We sought to confirm the correlation between VL results obtained using PSC prepared from venous blood to those from plasma or DBS, as well as PSC prepared with capillary blood from a finger prick. PSC, DBS and plasma were prepared with blood from HIV-1 infected persons attending a primary care clinic in Kampala, Uganda. VL in PSC and plasma was measured using cobas HIV-1 (Roche Diagnostics), while VL in DBS was measured with RealTime HIV-1 (Abbott Diagnostics). The correlation between VL from plasma and PSC made from capillary or venous blood was high (regression coefficient of determination r2 between 0.87 and 0.91), and there was good agreement based on mean bias (-0.14 to 0.24 log10 copies/mL) and classification of VL above or below 1000 copies/mL (91.4% agreement). In contrast, VL from DBS was lower than plasma or PSC (mean bias 0.51 to 0.63 log10 copies/mL) and not as well correlated (r2 0.78 to 0.81, 75.1-80.5% agreement). These results confirm the utility of PSC as an alternative specimen type for HIV-1 viral load measurement in areas where preparation and optimal storage or shipment of plasma is an obstacle to provision of treatment and care of HIV-1 infected people.

A protocol for feasibility of plasma based GeneXpert platform and Dried Blood Spot (DBS) based Abbott platform for HIV-1 viral load testing among the people living with HIV attending ART centers in India

BACKGROUND

HIV-1 Viral load (VL) measures efficiency of the antiretroviral therapy (ART) after treatment initiation and helps to diagnose virological failures at an early stage. Current VL assays require sophisticated laboratory facilities. As well as there are other challenges pertaining to insufficient laboratory access, cold-chain management and sample transportation. Hence the number of HIV-1 VL testing laboratories is inadequate in the resource limited settings. The revised national tuberculosis elimination programme (NTEP) in India has developed a vast network of point of care (PoC) testing facilities for diagnosis of tuberculosis and several GeneXpert platforms are functional under this programme. Both the GeneXpert HIV-1 assay and HIV-1 Abbott real time assay are comparable and GeneXpert HIV-1 assay can be used as PoC for HIV-1 Viral load testing. Also, the dried blood spot (DBS) as a sample type has been considered as a good option for HIV-1 VL testing in hard to reach areas. This protocol is therefore developed to assess the feasibility of integrating HIV-1 VL testing among people living with HIV (PLHIV) attending ART centres using the two public health models under the current programme: 1. HIV-1 VL testing using GeneXpert platform and plasma as a sample type, and 2. HIV-1 VL testing using Abbott m2000 platform and DBS as a sample type.

METHODS

This ethically approved feasibility study will be implemented at two moderate to high burden ART centres where VL testing facility is not available in the town. Under Model-1, arrangements will be made to carry out VL testing on the adjacent GeneXpert facility and under Model-2, DBS will be prepared on site and couriered to identified viral load testing laboratories. In order to assess the feasibility, data will be collected on pretested questionnaire pertaining to number of samples tested for VL testing, number of samples tested for tuberculosis (TB) diagnosis and the turnaround time (TAT). In-depth interviews will be conducted among the service providers at ART centre and different laboratories for addressing any issues regarding the model implementation.

RESULTS

The proportion of PLHIV tested for VL at ART centres, total TAT for both models including TAT for sample transportation, sample testing and receipt of results as well as proportion of sample rejections and reasons for the same, correlation coefficient between DBS based and plasma based VL testing will be estimated using various statistical tools.

CONCLUSION

If found promising, these public health approaches will be helpful for the policy makers and program implementation in scaling up HIV-1 viral load testing within India.