Journal Article > ResearchFull Text
AIDS. 2019 October 1; Volume 33 (Issue 12); 1881-1889.; DOI:10.1097/QAD.0000000000002303
Sacks JA, Fong Y, Gonzalez MP, Andreotti M, Baliga S, et al.
AIDS. 2019 October 1; Volume 33 (Issue 12); 1881-1889.; DOI:10.1097/QAD.0000000000002303
BACKGROUND
Coverage of viral load testing remains low with only half of the patients in need having adequate access. Alternative technologies to high throughput centralized machines can be used to support viral load scale-up; however, clinical performance data are lacking. We conducted a meta-analysis comparing the Cepheid Xpert HIV-1 viral load plasma assay to traditional laboratory-based technologies.
METHODS
Cepheid Xpert HIV-1 and comparator laboratory technology plasma viral load results were provided from 13 of the 19 eligible studies, which accounted for a total of 3790 paired data points. We used random effects models to determine the accuracy and misclassification at various treatment failure thresholds (detectable, 200, 400, 500, 600, 800 and 1000 copies/ml).
RESULTS
Thirty percent of viral load test results were undetectable, while 45% were between detectable and 10 000 copies/ml and the remaining 25% were above 10 000 copies/ml. The median Xpert viral load was 119 copies/ml and the median comparator viral load was 157 copies/ml, while the log10 bias was 0.04 (0.02–0.07). The sensitivity and specificity to detect treatment failure were above 95% at all treatment failure thresholds, except for detectable, at which the sensitivity was 93.33% (95% confidence interval: 88.2–96.3) and specificity was 80.56% (95% CI: 64.6–90.4).
CONCLUSION
The Cepheid Xpert HIV-1 viral load plasma assay results were highly comparable to laboratory-based technologies with limited bias and high sensitivity and specificity to detect treatment failure. Alternative specimen types and technologies that enable decentralized testing services can be considered to expand access to viral load.
Coverage of viral load testing remains low with only half of the patients in need having adequate access. Alternative technologies to high throughput centralized machines can be used to support viral load scale-up; however, clinical performance data are lacking. We conducted a meta-analysis comparing the Cepheid Xpert HIV-1 viral load plasma assay to traditional laboratory-based technologies.
METHODS
Cepheid Xpert HIV-1 and comparator laboratory technology plasma viral load results were provided from 13 of the 19 eligible studies, which accounted for a total of 3790 paired data points. We used random effects models to determine the accuracy and misclassification at various treatment failure thresholds (detectable, 200, 400, 500, 600, 800 and 1000 copies/ml).
RESULTS
Thirty percent of viral load test results were undetectable, while 45% were between detectable and 10 000 copies/ml and the remaining 25% were above 10 000 copies/ml. The median Xpert viral load was 119 copies/ml and the median comparator viral load was 157 copies/ml, while the log10 bias was 0.04 (0.02–0.07). The sensitivity and specificity to detect treatment failure were above 95% at all treatment failure thresholds, except for detectable, at which the sensitivity was 93.33% (95% confidence interval: 88.2–96.3) and specificity was 80.56% (95% CI: 64.6–90.4).
CONCLUSION
The Cepheid Xpert HIV-1 viral load plasma assay results were highly comparable to laboratory-based technologies with limited bias and high sensitivity and specificity to detect treatment failure. Alternative specimen types and technologies that enable decentralized testing services can be considered to expand access to viral load.
Journal Article > CommentaryFull Text
PLOS Med. 2019 May 29; Volume 16 (Issue 5); e1002820.; DOI:10.1371/journal.pmed.1002820
Ehrenkranz PD, Baptiste SL, Bygrave H, Ellman T, Doi N, et al.
PLOS Med. 2019 May 29; Volume 16 (Issue 5); e1002820.; DOI:10.1371/journal.pmed.1002820
Journal Article > Meta-AnalysisAbstract
AIDS. 2019 October 1; DOI:10.1097/QAD.0000000000002303.
Sacks JA, Fong Y, Gonzalez MP, Andreotti M, Baliga S, et al.
AIDS. 2019 October 1; DOI:10.1097/QAD.0000000000002303.
Journal Article > ResearchFull Text
Nature. 2015 December 1; Volume 528 (Issue 7580); S68-S76.; DOI:10.1038/nature16046
Phillips AN, Shroufi A, Vojnov L, Cohn J, Roberts TR, et al.
Nature. 2015 December 1; Volume 528 (Issue 7580); S68-S76.; DOI:10.1038/nature16046
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.
Journal Article > CommentaryFull Text
Clin Infect Dis. 2018 March 4; Volume 66 (Issue suppl_2); S106-SS110.; DOI:10.1093/cid/cix1139
Ford NP, Meintjes GA, Calmy A, Bygrave H, Migone C, et al.
Clin Infect Dis. 2018 March 4; Volume 66 (Issue suppl_2); S106-SS110.; DOI:10.1093/cid/cix1139
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.