Building Integrated Testing Programs for Infectious Diseases.

In the past 2 decades, testing services for diseases such as human immunodeficiency virus (HIV), tuberculosis, and malaria have expanded dramatically. Investments in testing capacity and supportive health systems have often been disease specific, resulting in siloed testing programs with suboptimal capacity, reduced efficiency, and limited ability to introduce additional tests or respond to new outbreaks. Emergency demand for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing overcame these silos and demonstrated the feasibility of integrated testing. Moving forward, an integrated public laboratory infrastructure that services multiple diseases, including SARS-CoV-2, influenza, HIV, tuberculosis, hepatitis, malaria, sexually transmitted diseases, and other infections, will help improve universal healthcare delivery and pandemic preparedness. However, integrated testing faces many barriers including poorly aligned health systems, funding, and policies. Strategies to overcome these include greater implementation of policies that support multidisease testing and treatment systems, diagnostic network optimization, bundled test procurement, and more rapid spread of innovation and best practices across disease programs.

Nucleic Acid Point-of-Care Testing to Improve Diagnostic Preparedness.

Testing programs for severe acute respiratory syndrome coronavirus 2 have relied on high-throughput polymerase chain reaction laboratory tests and rapid antigen assays to meet diagnostic needs. Both technologies are essential; however, issues of cost, accessibility, manufacturing delays, and performance have limited their use in low-resource settings and contributed to the global inequity in coronavirus disease 2019 testing. Emerging low-cost, multidisease point-of-care nucleic acid tests may address these limitations and strengthen pandemic preparedness, especially within primary healthcare where most cases of disease first present. Widespread deployment of these novel technologies will also help close long-standing test access gaps for other diseases, including tuberculosis, human immunodeficiency virus, cervical cancer, viral hepatitis, and sexually transmitted infections. We propose a more optimized testing framework based on greater use of point-of-care nucleic acid tests together with rapid immunologic assays and high-throughput laboratory molecular tests to improve the diagnosis of priority endemic and epidemic diseases, as well as strengthen the overall delivery of primary healthcare services.

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

BACKGROUND: Accurate routine HIV viral load testing is essential for assessing the efficacy of antiretroviral treatment (ART) regimens and the emergence of drug resistance. While the use of plasma specimens is the standard for viral load testing, its use is restricted by the limited ambient temperature stability of viral load biomarkers in whole blood and plasma during storage and transportation and the limited cold chain available between many health care facilities in resource-limited settings. Alternative specimen types and technologies, such as dried blood spots, may address these issues and increase access to viral load testing; however, their technical performance is unclear. To address this, we conducted a meta-analysis comparing viral load results from paired dried blood spot and plasma specimens analyzed with commonly used viral load testing technologies. METHODS AND FINDINGS: Standard databases, conferences, and gray literature were searched in 2013 and 2018. Nearly all studies identified (60) were conducted between 2007 and 2018. Data from 40 of the 60 studies were included in the meta-analysis, which accounted for a total of 10,871 paired dried blood spot:plasma data points. We used random effects models to determine the bias, accuracy, precision, and misclassification for each viral load technology and to account for between-study variation. Dried blood spot specimens produced consistently higher mean viral loads across all technologies when compared to plasma specimens. However, when used to identify treatment failure, each technology compared best to plasma at a threshold of 1,000 copies/ml, the present World Health Organization recommended treatment failure threshold. Some heterogeneity existed between technologies; however, 5 technologies had a sensitivity greater than 95%. Furthermore, 5 technologies had a specificity greater than 85% yet 2 technologies had a specificity less than 60% using a treatment failure threshold of 1,000 copies/ml. The study's main limitation was the direct applicability of findings as nearly all studies to date used dried blood spot samples prepared in laboratories using precision pipetting that resulted in consistent input volumes. CONCLUSIONS: This analysis provides evidence to support the implementation and scale-up of dried blood spot specimens for viral load testing using the same 1,000 copies/ml treatment failure threshold as used with plasma specimens. This may support improved access to viral load testing in resource-limited settings lacking the required infrastructure and cold chain storage for testing with plasma specimens.

Global Health Facility-Based Interventions to Achieve UNAIDS 90-90-90: A Systematic Review and Narrative Analysis.

To evaluate whether health facility-based HIV interventions align with UNAIDS 90-90-90 targets, we performed a systematic review through the lens of UNAIDS targets. We searched 11 databases, retrieving 5201 citations with 26 eligible studies classified by country income and UNAIDS target. We analyzed whether reporting of study outcome metrics was in line with UNAIDS targets using a standardized extraction form and results were summarized in a narrative synthesis given data heterogeneity. We also assessed the quality of randomized trials with the Cochrane Risk of Bias Tool and observational studies with the Newcastle-Ottawa Scale. Stratification of interventions by country income level revealed themes in successful interventions that provide insight for scale-up in similar resource contexts. Few studies reported outcomes using metrics according to UNAIDS targets. Standardization of reporting according to the UNAIDS framework could facilitate comparability of interventions and inform country-level progress on an international scale.

Evaluation of the Whole-Blood Alere Q NAT Point-of-Care RNA Assay for HIV-1 Viral Load Monitoring in a Primary Health Care Setting in Mozambique.

Viral load testing is the WHO-recommended monitoring assay for patients on HIV antiretroviral therapy (ART). Point-of-care (POC) assays may help improve access to viral load testing in resource-limited settings. We compared the performance of the Alere Q NAT POC viral load technology (Alere Technologies, Jena, Germany), measuring total HIV RNA using finger prick capillary whole-blood samples collected in a periurban health center, with that of a laboratory-based plasma RNA test (Roche Cobas Ampliprep/Cobas TaqMan v2) conducted on matched venous blood samples. The whole-blood Alere Q NAT POC assay produced results with a bias of 0.8593 log copy/ml compared to the laboratory-based plasma assay. However, at above 10,000 copies/ml, the bias was 0.07 log copy/ml. Using the WHO-recommended threshold to determine ART failure of 1,000 copies/ml, the sensitivity and specificity of the whole-blood Alere Q NAT POC assay were 96.83% and 47.80%, respectively. A cutoff of 10,000 copies/ml of whole blood with the Alere Q NAT POC assay appears to be a better predictor of ART failure threshold (1,000 copies/ml of plasma), with a sensitivity of 84.0% and specificity of 90.3%. The precision of the whole-blood Alere Q NAT POC assay was comparable to that observed with the laboratory technology (5.4% versus 7.5%) between detectable paired samples. HIV POC viral load testing is feasible at the primary health care level. Further research on the value of whole-blood viral load to monitor antiretroviral therapy is warranted.

Implementation of HIV and Tuberculosis Diagnostics: The Importance of Context.

BACKGROUND: Novel diagnostics have been widely applied across human immunodeficiency virus (HIV) and tuberculosis prevention and treatment programs. To achieve the greatest impact, HIV and tuberculosis diagnostic programs must carefully plan and implement within the context of a specific healthcare system and the laboratory capacity. METHODS: A workshop was convened in Cape Town in September 2014. Participants included experts from laboratory and clinical practices, officials from ministries of health, and representatives from industry. RESULTS: The article summarizes best practices, challenges, and lessons learned from implementation experiences across sub-Saharan Africa for (1) building laboratory programs within the context of a healthcare system; (2) utilizing experience of clinicians and healthcare partners in planning and implementing the right diagnostic; and (3) evaluating the effects of new diagnostics on the healthcare system and on patient health outcomes. CONCLUSIONS: The successful implementation of HIV and tuberculosis diagnostics in resource-limited settings relies on careful consideration of each specific context.

A meta-analysis of the performance of the Pima™ CD4 for point of care testing.

BACKGROUND: The Alere point-of-care (POC) Pima™ CD4 analyzer allows for decentralized testing and expansion to testing antiretroviral therapy (ART) eligibility. A consortium conducted a pooled multi-data technical performance analysis of the Pima CD4. METHODS: Primary data (11,803 paired observations) comprised 22 independent studies between 2009-2012 from the Caribbean, Asia, Sub-Saharan Africa, USA and Europe, using 6 laboratory-based reference technologies. Data were analyzed as categorical (including binary) and numerical (absolute) observations using a bivariate and/or univariate random effects model when appropriate. RESULTS: At a median reference CD4 of 383 cells/µl the mean Pima CD4 bias is -23 cells/µl (average bias across all CD4 ranges is 10 % for venous and 15% for capillary testing). Sensitivity of the Pima CD4 is 93% (95% confidence interval [CI] 91.4% - 94.9%) at 350 cells/µl and 96% (CI 95.2% - 96.9%) at 500 cells/µl, with no significant difference between venous and capillary testing. Sensitivity reduced to 86% (CI 82% - 89%) at 100 cells/µl (for Cryptococcal antigen (CrAg) screening), with a significant difference between venous (88%, CI: 85% - 91%) and capillary (79%, CI: 73% - 84%) testing. Total CD4 misclassification is 2.3% cases at 100 cells/µl, 11.0% at 350 cells/µl and 9.5 % at 500 cells/µl, due to higher false positive rates which resulted in more patients identified for treatment. This increased by 1.2%, 2.8% and 1.8%, respectively, for capillary testing. There was no difference in Pima CD4 misclassification between the meta-analysis data and a population subset of HIV+ ART naïve individuals, nor in misclassification among operator cadres. The Pima CD4 was most similar to Beckman Coulter PanLeucogated CD4, Becton Dickinson FACSCalibur and FACSCount, and less similar to Partec CyFlow reference technologies. CONCLUSIONS: The Pima CD4 may be recommended using venous-derived specimens for screening (100 cells/µl) for reflex CrAg screening and for HIV ART eligibility at 350 cells/µl and 500 cells/µl thresholds using both capillary and venous derived specimens. These meta-analysis findings add to the knowledge of acceptance criteria of the Pima CD4 and future POC tests, but implementation and impact will require full costing analysis.

The clinical and economic impact of point-of-care CD4 testing in mozambique and other resource-limited settings: a cost-effectiveness analysis.

BACKGROUND: Point-of-care CD4 tests at HIV diagnosis could improve linkage to care in resource-limited settings. Our objective is to evaluate the clinical and economic impact of point-of-care CD4 tests compared to laboratory-based tests in Mozambique. METHODS AND FINDINGS: We use a validated model of HIV testing, linkage, and treatment (CEPAC-International) to examine two strategies of immunological staging in Mozambique: (1) laboratory-based CD4 testing (LAB-CD4) and (2) point-of-care CD4 testing (POC-CD4). Model outcomes include 5-y survival, life expectancy, lifetime costs, and incremental cost-effectiveness ratios (ICERs). Input parameters include linkage to care (LAB-CD4, 34%; POC-CD4, 61%), probability of correctly detecting antiretroviral therapy (ART) eligibility (sensitivity: LAB-CD4, 100%; POC-CD4, 90%) or ART ineligibility (specificity: LAB-CD4, 100%; POC-CD4, 85%), and test cost (LAB-CD4, US$10; POC-CD4, US$24). In sensitivity analyses, we vary POC-CD4-specific parameters, as well as cohort and setting parameters to reflect a range of scenarios in sub-Saharan Africa. We consider ICERs less than three times the per capita gross domestic product in Mozambique (US$570) to be cost-effective, and ICERs less than one times the per capita gross domestic product in Mozambique to be very cost-effective. Projected 5-y survival in HIV-infected persons with LAB-CD4 is 60.9% (95% CI, 60.9%-61.0%), increasing to 65.0% (95% CI, 64.9%-65.1%) with POC-CD4. Discounted life expectancy and per person lifetime costs with LAB-CD4 are 9.6 y (95% CI, 9.6-9.6 y) and US$2,440 (95% CI, US$2,440-US$2,450) and increase with POC-CD4 to 10.3 y (95% CI, 10.3-10.3 y) and US$2,800 (95% CI, US$2,790-US$2,800); the ICER of POC-CD4 compared to LAB-CD4 is US$500/year of life saved (YLS) (95% CI, US$480-US$520/YLS). POC-CD4 improves clinical outcomes and remains near the very cost-effective threshold in sensitivity analyses, even if point-of-care CD4 tests have lower sensitivity/specificity and higher cost than published values. In other resource-limited settings with fewer opportunities to access care, POC-CD4 has a greater impact on clinical outcomes and remains cost-effective compared to LAB-CD4. Limitations of the analysis include the uncertainty around input parameters, which is examined in sensitivity analyses. The potential added benefits due to decreased transmission are excluded; their inclusion would likely further increase the value of POC-CD4 compared to LAB-CD4. CONCLUSIONS: POC-CD4 at the time of HIV diagnosis could improve survival and be cost-effective compared to LAB-CD4 in Mozambique, if it improves linkage to care. POC-CD4 could have the greatest impact on mortality in settings where resources for HIV testing and linkage are most limited. Please see later in the article for the Editors' Summary.

Opportunities and challenges for cost-efficient implementation of new point-of-care diagnostics for HIV and tuberculosis.

Stakeholders agree that supporting high-quality diagnostics is essential if we are to continue to make strides in the fight against human immunodeficiency virus (HIV) and tuberculosis. Despite the need to strengthen existing laboratory infrastructure, which includes expanding and developing new laboratories, there are clear diagnostic needs where conventional laboratory support is insufficient. Regarding HIV, rapid point-of-care (POC) testing for initial HIV diagnosis has been successful, but several needs remain. For tuberculosis, several new diagnostic tests have recently been endorsed by the World Health Organization, but a POC test remains elusive. Human immunodeficiency virus and tuberculosis are coendemic in many high prevalence locations, making parallel diagnosis of these conditions an important consideration. Despite its clear advantages, POC testing has important limitations, and laboratory-based testing will continue to be an important component of future diagnostic networks. Ideally, a strategic deployment plan should be used to define where and how POC technologies can be most efficiently and cost effectively integrated into diagnostic algorithms and existing test networks prior to widespread scale-up. In this fashion, the global community can best harness the tremendous capacity of novel diagnostics in fighting these 2 scourges.

Implementing SARS-CoV-2 antigen testing scale-up in Rwanda: retrospective analysis of national programme data and qualitative findings.

OBJECTIVES: Reverse transcriptase PCR is the most sensitive test for SARS-CoV-2 diagnosis. However, the scale-up of these tests in low-income and middle-income countries (LMICs) has been limited due to infrastructure and cost. Antigen rapid diagnostic tests are an alternative option for diagnosing active infection that may allow for faster, easier, less expensive and more widespread testing. We compared the implementation of antigen and PCR testing programmes in Rwanda. DESIGN: We retrospectively reviewed routinely collected PCR and antigen testing data for all reported tests conducted nationally. We administered semiquantitative surveys to healthcare workers (HCWs) involved in COVID-19 testing and care and clients receiving antigen testing. SETTING: Rwanda, November 2020-July 2021. PARTICIPANTS: National SARS-CoV-2 testing data; 49 HCWs involved in COVID-19 testing and care; 145 clients receiving antigen testing. INTERVENTIONS: None (retrospective analysis of programme data). PRIMARY AND SECONDARY OUTCOME MEASURES: Test volumes, turnaround times, feasibility and acceptability of antigen testing. RESULTS: Data from 906 204 antigen tests and 445 235 PCR tests were included. Antigen testing increased test availability and case identification compared with PCR and had a median results return time of 0 days (IQR: 0-0). In contrast, PCR testing time ranged from 1 to 18 days depending on the sample collection site/district. Both HCWs and clients indicated that antigen testing was feasible and acceptable. Some HCWs identified stockouts and limited healthcare staff as challenges. CONCLUSIONS: Antigen testing facilitated rapid expansion and decentralisation of SARS-CoV-2 testing across lower tier facilities in Rwanda, contributed to increased case identification, reduced test processing times, and was determined to be feasible and acceptable to clients and providers. Antigen testing will be an essential component of SARS-CoV-2 test and treat programmes in LMICs.

Human papillomavirus testing using existing nucleic acid testing platforms to screen women for cervical cancer: implementation studies from five sub-Saharan African countries.

OBJECTIVES: To demonstrate acceptability and operational feasibility of introducing human papillomavirus (HPV) testing as a principal cervical cancer screening method in public health programmes in sub-Saharan Africa. SETTING: 45 primary and secondary health clinics in Malawi, Nigeria, Senegal, Uganda and Zimbabwe. PARTICIPANTS: 15 766 women aged 25-54 years presenting at outpatient departments (Senegal only, general population) or at antiretroviral therapy clinics (all other countries, HIV-positive women only). Eligibility criteria followed national guidelines for cervical cancer screening. INTERVENTIONS: HPV testing was offered to eligible women as a primary screening for cervical cancer, and HPV-positive women were referred for visual inspection with acetic acid (VIA), and if lesions identified, received treatment or referral. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcomes were the proportion of HPV-positive women who received results and linked to VIA and the proportion of HPV-positive and VIA-positive women who received treatment. RESULTS: A total of 15 766 women were screened and tested for HPV, among whom 14 564 (92%) had valid results and 4710/14 564 (32%) were HPV positive. 13 837 (95%) of valid results were returned to the clinic and 3376 (72%) of HPV-positive women received results. Of women receiving VIA (n=2735), 715 (26%) were VIA-positive and 622 (87%) received treatment, 75% on the same day as VIA. CONCLUSIONS: HPV testing was found to be feasible across the five study countries in a public health setting, although attrition was seen at several key points in the cascade of care, namely results return to women and linkage to VIA. Once women received VIA, if eligible, the availability of on-site cryotherapy and thermal ablation allowed for same-day treatment. With sufficient resources and supportive infrastructure to ensure linkage to treatment, use of HPV testing for cervical cancer screening as recommended by WHO is a promising model in low-income and middle-income countries.

Effect of point-of-care CD4 cell count tests on retention of patients and rates of antiretroviral therapy initiation in primary health clinics: an observational cohort study.

BACKGROUND: Loss to follow-up of HIV-positive patients before initiation of antiretroviral therapy can exceed 50% in low-income settings and is a challenge to the scale-up of treatment. We implemented point-of-care counting of CD4 cells in Mozambique and assessed the effect on loss to follow-up before immunological staging and treatment initiation. METHODS: In this observational cohort study, data for enrolment into HIV management and initiation of antiretroviral therapy were extracted retrospectively from patients' records at four primary health clinics providing HIV treatment and point-of-care CD4 services. Loss to follow-up and the duration of each preparatory step before treatment initiation were measured and compared with baseline data from before the introduction of point-of-care CD4 testing. FINDINGS: After the introduction of point-of-care CD4 the proportion of patients lost to follow-up before completion of CD4 staging dropped from 57% (278 of 492) to 21% (92 of 437) (adjusted odds ratio [OR] 0·2, 95% CI 0·15-0·27). Total loss to follow-up before initiation of antiretroviral treatment fell from 64% (314 of 492) to 33% (142 of 437) (OR 0·27, 95% CI 0·21-0·36) and the proportion of enrolled patients initiating antiretroviral therapy increased from 12% (57 of 492) to 22% (94 of 437) (OR 2·05, 95% CI 1·42-2·96). The median time from enrolment to antiretroviral therapy initiation reduced from 48 days to 20 days (p<0·0001), primarily because of a reduction in the median time taken to complete CD4 staging, which decreased from 32 days to 3 days (p<0·0001). Loss to follow-up between staging and antiretroviral therapy initiation did not change significantly (OR 0·84, 95% CI 0·49-1·45). INTERPRETATION: Point-of-care CD4 testing enabled clinics to stage patients rapidly on-site after enrolment, which reduced opportunities for pretreatment loss to follow-up. As a result, more patients were identified as eligible for and initiated antiretroviral treatment. Point-of-care testing might therefore be an effective intervention to reduce pretreatment loss to follow-up. FUNDING: Absolute Return for Kids and UNITAID.

HIV viral load assays when used with whole blood perform well as a diagnostic assay for infants.

OBJECTIVE: Over the past several years, only approximately 50% of HIV-exposed infants received an early infant diagnosis test within the first two months of life. While high attrition and mortality account for some of the shortcomings in identifying HIV-infected infants early and putting them on life-saving treatment, fragmented and challenging laboratory systems are an added barrier. We sought to determine the accuracy of using HIV viral load assays for infant diagnosis of HIV. METHODS: We enrolled 866 Ugandan infants between March-April 2018 for this study after initial laboratory diagnosis. The median age was seven months, while 33% of infants were less than three months of age. Study testing was done using either the Roche or Abbott molecular technologies at the Central Public Health Laboratory. Dried blood spot samples were prepared according to manufacturer-recommended protocols for both the qualitative and quantitative assays. Viral load test samples for the Roche assay were processed using two different buffers: phosphate-buffered saline (PBS: free virus elution viral load protocol [FVE]) and Sample Pre-Extraction Reagent (SPEX: qualitative buffer). Dried blood spot samples were processed for both assays on the Abbott using the manufacturer's standard infant diagnosis protocol. All infants received a qualitative test for clinical management and additional paired quantitative tests. RESULTS: 858 infants were included in the analysis, of which 50% were female. Over 75% of mothers received antiretroviral therapy, while approximately 65% of infants received infant prophylaxis. The Roche SPEX and Abbott technologies had high sensitivity (>95%) and specificity (>98%). The Roche FVE had lower sensitivity (85%) and viral load values. CONCLUSIONS: To simplify and streamline laboratory practices, HIV viral load may be used to diagnose HIV infection in infants, particularly using the Roche SPEX and Abbott technologies.

Near-point-of-care viral load testing during pregnancy and viremia at delivery.

OBJECTIVES: Assess whether near-point-of-care (POC) viral load testing at the first antenatal care visit (ANC1) increased the proportion of women taking antiretroviral therapy who were virally suppressed at delivery through expedited clinical action. DESIGN: Difference-in-difference analysis. METHODS: At 20 public sector facilities in Zimbabwe, 10 implemented near-POC viral load testing at ANC1 (August 2019 to November 2020) and 10 used centralized viral load testing at ANC1. Study endpoints included time to result received, clinical action, and unsuppressed viral load (UVL; >1000 copies/ml) at delivery. RESULTS: Of 1782 women, only 46% came for ANC1 before their third trimester. Preimplementation, 28% of women received viral load testing at ANC1, increasing to 86% during implementation. In the near-POC viral load arm, women were more likely to receive their result within 30 days of ANC1 sample collection compared with the centralized laboratory arm [54 versus 14%, relative risk (RR): 4.17, 95% confidence interval (CI) 1.82-9.55], as well as receive clinical action among those with UVL (63 versus 8%, RR 7.88; 95% CI 1.53-40.47). However, we did not observe significant changes in risk of UVL at delivery with near-POC viral load (RR 1.02, 95% CI 0.95-1.10). CONCLUSION: ANC1 viral load coverage was initially low. Near-POC viral load testing at ANC1 dramatically improved the timeliness of result receipt by patients and clinical action for those with an UVL. Although we did not observe a significant impact of provision of near-POC viral load at ANC1 on re-suppression at delivery, potentially because of late presentation for ANC1, continued near-POC viral load testing during pregnancy and delivery may reduce UVL and mother-to-child transmission risk.

Feasibility and impact of near-point-of-care integrated tuberculosis/HIV testing in Malawi and Zimbabwe.

OBJECTIVES: Near-point-of-care (POC) testing for early infant diagnosis (EID) and viral load expedites clinical action and improves outcomes but requires capital investment. We assessed whether excess capacity on existing near-POC devices used for TB diagnosis could be leveraged to increase near-POC HIV molecular testing, termed integrated testing, without compromising TB services. DESIGN: Preimplementation/postimplementation studies in 10 health facilities in Malawi and 8 in Zimbabwe. METHODS: Timeliness of EID and viral load test results and clinical action were compared between centralized and near-POC testing using Somers' D tests (continuous indicators) and risk ratios (RR, binary indicators); TB testing/treatment rates and timeliness were analyzed preintegration/postintegration. RESULTS: With integration, average device utilization increased but did not exceed 55%. Despite the addition of HIV testing, TB test volumes, timeliness, and treatment initiations were maintained. Although few HIV-positive infants were identified, near-POC EID testing improved treatment initiation within 1 month by 57% compared with centralized EID [Malawi RR: 1.57, 95% confidence interval (CI) 0.98-2.52], and near-POC viral load testing significantly increased the proportion of patients with elevated viral load receiving clinical action within 1 month (Zimbabwe RR: 5.26, 95% CI 3.38-8.20; Malawi RR: 3.90, 95% CI 2.58-5.91). CONCLUSION: Integrating TB/HIV testing using existing multidisease platforms is feasible and enables increased access to rapid diagnostics without disrupting existing TB services. Our results serve as an example of a novel, efficient implementation model that can increase access to critical testing services across disease silos and should be considered for additional clinical applications.

Evaluation of near point-of-care viral load implementation in public health facilities across seven countries in sub-Saharan Africa.

INTRODUCTION: In many low- and middle-income countries, HIV viral load (VL) testing occurs at centralized laboratories and time-to-result-delivery is lengthy, preventing timely monitoring of HIV treatment adherence. Near point-of-care (POC) devices, which are placed within health facility laboratories rather than clinics themselves (i.e. "true" POC), can offer VL in conjunction with centralized laboratories to expedite clinical decision making and improve outcomes, especially for patients at high risk of treatment failure. We assessed impacts of near-POC VL testing on result receipt and clinical action in public sector programmes in Cameroon, Democratic Republic of Congo, Kenya, Malawi, Senegal, Tanzania and Zimbabwe. METHODS: Routine health data were collected retrospectively after introducing near-POC VL testing at 57 public sector health facilities (2017 to 2019, country-dependent). Where possible, key indicators were compared to data from patients receiving centralized laboratory testing using hazard ratios and the Somers' D test. RESULTS: Data were collected from 6795 tests conducted on near-POC and 17614 tests on centralized laboratory-based platforms. Thirty-one percent (2062/6694) of near-POC tests were conducted for high-risk populations: pregnant and breastfeeding women, children and those with suspected failure. Compared to conventional testing, near-POC improved the median time from sample collection to return of results to patient [six vs. sixty-eight days, effect size: -32.2%; 95% CI: -41.0% to -23.4%] and to clinical action for individuals with an elevated HIV VL [three vs. fourty-nine days, effect size: -35.4%; 95% CI: -46.0% to -24.8%]. Near-POC VL results were two times more likely to be returned to the patient within 90 days compared to centralized tests [50% (1781/3594) vs. 27% (4172/15271); aHR: 2.22, 95% CI: 2.05 to 2.39]. Thirty-seven percent (340/925) of patients with an elevated near-POC HIV VL result had documented clinical follow-up actions within 30 days compared to 7% (167/2276) for centralized testing. CONCLUSIONS: Near-POC VL testing enabled rapid test result delivery for high-risk populations and led to significant improvements in the timeliness of patient result receipt compared to centralized testing. While there was some improvement in time-to-clinical action with near-POC VL testing, major gaps remained. Strengthening of systems supporting the utilization of results for patient management are needed to truly capitalize on the benefits of decentralized testing.

Point-of-care testing can achieve same-day diagnosis for infants and rapid ART initiation: results from government programmes across six African countries.

INTRODUCTION: Point-of-care (POC) early infant diagnosis (EID) testing has been shown to dramatically decrease turnaround times from sample collection to caregiver result receipt and time to ART initiation for HIV-positive infants compared to centralized laboratory testing. As governments in sub-Saharan Africa implement POC EID technologies, we report on the feasibility and effectiveness of POC EID testing and the impact of same-day result delivery on rapid ART initiation within national programmes across six countries. METHODS: This pre-/post-evaluation compared centralized laboratory-based (pre) with POC (post) EID testing in 52 facilities across Cameroon, Democratic Republic of Congo, Ethiopia, Kenya, Senegal and Zimbabwe between April 2017 and October 2019 (country-dependent). Data were collected retrospectively from routine records at health facilities for all infants tested under two years of age. Hazard ratios and 95% confidence intervals were calculated to compare time-to-event outcomes, visualized with Kaplan-Meier curves, and the Somers' D test was used to compare continuous outcomes. RESULTS: Data were collected for 2892 EID tests conducted on centralized laboratory-based platforms and 4610 EID tests on POC devices with 127 (4%) and 192 (4%) HIV-positive infants identified, respectively. POC EID significantly reduced the time from sample collection to caregiver result receipt (POC median: 0 days, IQR: 0 to 0 vs. centralized: 35 days, IQR: 26 to 56) and time from sample collection to ART initiation for HIV-positive infants (POC median: 1 day, IQR: 0 to 7 vs. centralized: 39 days, IQR: 26 to 57). With POC testing, 72% of infants received results on the same day as sample collection; HIV-positive infants with a same-day diagnosis had six times the rate of ART initiation compared to those diagnosed one or more days after sample collection (HR: 6.39; 95% CI: 3.44 to 11.85). CONCLUSIONS: Same-day diagnosis and treatment initiation for infants is possible with POC EID within routine government-led and -supported public sector healthcare facilities in resource-limited settings. Given that POC EID allows for rapid ART initiation, aligning to the World Health Organization's recommendation of ART initiation within seven days, its use in public sector programmes has the potential to reduce overall mortality for infants with HIV through early treatment initiation.

Modern diagnostic technologies for HIV.

Novel diagnostic technologies, including nanotechnology, microfluidics, -omics science, next-generation sequencing, genomics big data, and machine learning, could contribute to meeting the UNAIDS 95-95-95 targets to end the HIV epidemic by 2030. Novel technologies include multiplexed technologies (including biomarker-based point-of-care tests and molecular platform technologies), biomarker-based combination antibody and antigen technologies, dried-blood-spot testing, and self-testing. Although biomarker-based rapid tests, in particular antibody-based tests, have dominated HIV diagnostics since the development of the first HIV test in the mid-1980s, targets such as nucleic acids and genes are now used in nanomedicine, biosensors, microfluidics, and -omics to enable early diagnosis of HIV. These novel technologies show promise as they are associated with ease of use, high diagnostic accuracy, rapid detection, and the ability to detect HIV-specific markers. Additional clinical and implementation research is needed to generate evidence for use of novel technologies and a public health approach will be required to address clinical and operational challenges to optimise their global deployment.

Building and Sustaining Optimized Diagnostic Networks to Scale-up HIV Viral Load and Early Infant Diagnosis.

BACKGROUND: Progress toward meeting the UNAIDS 2014 HIV treatment (90-90-90) targets has been slow in some countries because of gaps in access to HIV diagnostic tests. Emerging point-of-care (POC) molecular diagnostic technologies for HIV viral load (VL) and early infant diagnosis (EID) may help reduce diagnostic gaps. However, these technologies need to be implemented in a complementary and strategic manner with laboratory-based instruments to ensure optimization. METHOD: Between May 2019 and February 2020, a systemic literature search was conducted in PubMed, the Cochrane Library, MEDLINE, conference abstracts, and other sources such as Unitaid, UNAIDS, WHO, and UNICEF websites to determine factors that would affect VL and EID scale-up. Data relevant to the search themes were reviewed for accuracy and were included. RESULTS: Collaborations among countries, implementing partners, and donors have identified a set of framework for the effective use of both POC-based and laboratory-based technologies in large-scale VL and EID testing programs. These frameworks include (1) updated testing policies on the operational utility of POC and laboratory-based technologies, (2) expanded integrated testing using multidisease diagnostic platforms, (3) laboratory network mapping, (4) use of more efficient procurement and supply chain approaches such as all-inclusive pricing and reagent rental, and (5) addressing systemic issues such as test turnaround time, sample referral, data management, and quality systems. CONCLUSIONS: Achieving and sustaining optimal VL and EID scale-up within tiered diagnostic networks would require better coordination among the ministries of health of countries, donors, implementing partners, diagnostic manufacturers, and strong national laboratory and clinical technical working groups.