Lara Vojnov

Sustainable HIV treatment in Africa through viral-load-informed differentiated care

There are inefficiencies in current approaches to monitoring patients on antiretroviral therapy in sub-Saharan Africa. Patients typically attend clinics every 1 to 3 months for clinical assessment. The clinic costs are comparable with the costs of the drugs themselves and CD4 counts are measured every 6 months, but patients are rarely switched to second-line therapies. To ensure sustainability of treatment programmes, a transition to more cost-effective delivery of antiretroviral therapy is needed. In contrast to the CD4 count, measurement of the level of HIV RNA in plasma (the viral load) provides a direct measure of the current treatment effect. Viral-load-informed differentiated care is a means of tailoring care so that those with suppressed viral load visit the clinic less frequently and attention is focussed on those with unsuppressed viral load to promote adherence and timely switching to a second-line regimen. The most feasible approach to measuring viral load in many countries is to collect dried blood spot samples for testing in regional laboratories; however, there have been concerns over the sensitivity and specificity of this approach to define treatment failure and the delay in returning results to the clinic. We use modelling to synthesize evidence and evaluate the cost-effectiveness of viral-load-informed differentiated care, accounting for limitations of dried blood sample testing. We find that viral-load-informed differentiated care using dried blood sample testing is cost-effective and is a recommended strategy for patient monitoring, although further empirical evidence as the approach is rolled out would be of value. We also explore the potential benefits of point-of-care viral load tests that may become available in the future.This article has not been written or reviewed by Nature editors. Nature accepts no responsibility for the accuracy of the information provided.

Reducing mortality in HIV-infected infants and achieving the 90-90-90 target through innovative diagnosis approaches

Despite significant gains in access to early infant diagnosis (EID) over the past decade, most HIV‐exposed infants still do not get tested for HIV in the first two months of life. For those who are tested, the long turnaround time between when the sample is drawn and when the results are returned leads to a high rate of loss to follow‐up, which in turn means that few infected infants start antiretroviral treatment. Consequently, there continues to be high mortality from perinatally acquired HIV, and the ambitious goals of 90% of infected children identified, 90% of identified children treated and 90% of treated children with sustained virologic suppression by 2020 seem far beyond our reach. The objective of this commentary is to review recent advances in the field of HIV diagnosis in infants and describe how these advances may overcome long‐standing barriers to access to testing and treatment.

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

BackgroundThe 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.MethodsPrimary 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.ResultsAt a median reference CD4 of 383 cells/μl the mean Pima CD4 bias is -23 cells/μl (average bias across all CD4 ranges is 10xa0% for venous and 15xa0% for capillary testing). Sensitivity of the Pima CD4 is 93xa0% (95xa0% confidence interval [CI] 91.4xa0% - 94.9xa0%) at 350 cells/μl and 96xa0% (CI 95.2xa0% - 96.9xa0%) at 500 cells/μl, with no significant difference between venous and capillary testing. Sensitivity reduced to 86xa0% (CI 82xa0% - 89xa0%) at 100 cells/μl (for Cryptococcal antigen (CrAg) screening), with a significant difference between venous (88xa0%, CI: 85xa0% - 91xa0%) and capillary (79xa0%, CI: 73xa0% - 84xa0%) testing. Total CD4 misclassification is 2.3xa0% cases at 100 cells/μl, 11.0xa0% at 350 cells/μl and 9.5xa0% at 500 cells/μl, due to higher false positive rates which resulted in more patients identified for treatment. This increased by 1.2xa0%, 2.8xa0% and 1.8xa0%, 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.ConclusionsThe 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.

Implementation and Operational Research: Expedited Results Delivery Systems Using GPRS Technology Significantly Reduce Early Infant Diagnosis Test Turnaround Times.

Abstract:The objective of this study was to quantify the impact of a new technology to communicate the results of an infant HIV diagnostic test on test turnaround time and to quantify the association between late delivery of test results and patient loss to follow-up. We used data collected during a pilot implementation of Global Package Radio Service (GPRS) printers for communicating results in the early infant diagnosis program in Mozambique from 2008 through 2010. Our dataset comprised 1757 patient records, of which 767 were from before implementation and 990 from after implementation of expedited results delivery system. We used multivariate logistic regression model to determine the association between late result delivery (more than 30 days between sample collection and result delivery to the health facility) and the probability of result collection by the infants caregiver. We used a sample selection model to determine the association between late result delivery to the facility and further delay in collection of results by the caregiver. The mean test turnaround time reduced from 68.13 to 41.05 days post–expedited results delivery system. Caregivers collected only 665 (37.8%) of the 1757 results. After controlling for confounders, the late delivery of results was associated with a reduction of approximately 18% (0.44 vs. 0.36; P < 0.01) in the probability of results collected by the caregivers (odds ratio = 0.67, P < 0.05). Late delivery of results was also associated with a further average increase in 20.91 days of delay in collection of results (P < 0.01). Early infant diagnosis program managers should further evaluate the cost-effectiveness of operational interventions (eg, GPRS printers) that reduce delays.

The WHO public health approach to HIV treatment and care: looking back and looking ahead

In 2006, WHO set forth its vision for a public health approach to delivering antiretroviral therapy. This approach has been broadly adopted in resource-poor settings and has provided the foundation for scaling up treatment to over 19·5 million people. There is a global commitment to end the AIDS epidemic as a public health threat by 2030 and, to support this goal, there are opportunities to adapt the public health approach to meet the ensuing challenges. These challenges include the need to improve identification of people with HIV infection through expanded approaches to testing; further simplify and improve treatment and laboratory monitoring; adapt the public health approach to concentrated epidemics; and link HIV testing, treatment, and care to HIV prevention. Implementation of these key public health principles will bring countries closer to the goals of controlling the HIV epidemic and providing universal health coverage.

Scaling up HIV viral load - Lessons from the large-scale implementation of HIV early infant diagnosis and CD4 testing

The scale‐up of effective HIV viral load (VL) testing is an urgent public health priority. Implementation of testing is supported by the availability of accurate, nucleic acid based laboratory and point‐of‐care (POC) VL technologies and strong WHO guidance recommending routine testing to identify treatment failure. However, test implementation faces challenges related to the developing health systems in many low‐resource countries. The purpose of this commentary is to review the challenges and solutions from the large‐scale implementation of other diagnostic tests, namely nucleic‐acid based early infant HIV diagnosis (EID) and CD4 testing, and identify key lessons to inform the scale‐up of VL.

Point-of-Care Viral Load Testing for Sub-Saharan Africa: Informing a Target Product Profile.

Point-of-care viral load tests are being developed to monitor patients on antiretroviral therapy (ART) in sub-Saharan Africa. Test design involves trade-offs between test attributes, including accuracy, complexity, robustness, and cost. We used a model of the human immunodeficiency virus epidemic and ART program in Zimbabwe and found that the attributes of a viral load testing approach that are most influential for cost effectiveness are avoidance of a high proportion of failed tests or results not received, use of an approach that best facilitates retention on ART, and the ability to facilitate greater use of differentiated care, including through expanding coverage of testing availability.

Managing Advanced HIV Disease in a Public Health Approach

Abstract In 2017, the World Health Organization (WHO) published guidelines for the management of advanced human immunodeficiency virus (HIV) disease within a public health approach. Recent data suggest that more than a third of people starting antiretroviral therapy (ART) do so with advanced HIV disease, and an increasing number of patients re-present to care at an advanced stage of HIV disease following a period of disengagement from care. These guidelines recommend a standardized package of care for adults, adolescents, and children, based on the leading causes of morbidity and mortality: tuberculosis, severe bacterial infections, cryptococcal meningitis, toxoplasmosis, and Pneumocystis jirovecii pneumonia. A package of targeted interventions to reduce mortality and morbidity was recommended, based on results of 2 recent randomized trials that both showed a mortality reduction associated with delivery of a simplified intervention package. Taking these results and existing recommendations into consideration, WHO recommends that a package of care be offered to those presenting with advanced HIV disease; depending on age and CD4 cell count, the package may include opportunistic infection screening and prophylaxis, including fluconazole preemptive therapy for those who are cryptococcal antigen positive and without evidence of meningitis. Rapid ART initiation and intensified adherence interventions should also be proposed to everyone presenting with advanced HIV disease.

Where have all the children gone? High HIV prevalence in infants attending nutrition and inpatient entry points

Despite notable progress towards PMTCT, only 50% of HIV‐exposed infants in sub‐Saharan Africa were tested within the first 2 months of life and only 30% of HIV‐infected infants are on antiretroviral treatment. This study assessed HIV prevalence in infants and children receiving care at various service entry points in primary healthcare facilities in Uganda.

Significant Patient Impact Observed Upon Implementation of Point-of-Care Early Infant Diagnosis Technologies in an Observational Study in Malawi

We conducted an observational study in Malawi to understand the patient impact of implementing point-of-care early infant diagnosis (POC EID). Antiretroviral treatment initiation rates were significantly improved with the implementation of same-day POC EID testing compared with referred, longer-turnaround laboratory-based testing.