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.
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).
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).
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.
aClinton Health Access Initiative, Boston, Massachusetts
bFred Hutchinson Cancer Research Center, Seattle, Washington
cWorld Health Organization, Geneva, Switzerland
dNational Center for Global Health, Istituto Superiore di Sanita, Viale Regina Elena, Rome, Italy
eKasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India
fCentre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
gGeorge Washington University, Washington, District of Columbia, USA
hProject San Francisco/Rwanda-Zambia HIV Research Group, Kigali, Rwanda
iICMR-National AIDS Research Institute, Pune, Maharashtra, India
jCentral Virology Laboratory, Public Health Services, Israel Ministry of Health, Tel – Hashomer, Israel
kNational Health Laboratory Quality Assurance and Training Centre, Dar es Salaam, Tanzania
lMedecins Sans Frontieres, Southern Medical Unit, Cape Town, South Africa
mNormandie University, Unirouen, Rouen University Hospital, Laboratory of Virology, Rouen, France
nY. R. Gaitonde Centre for AIDS Research and Education, Taramani, Chennai, Tamil Nadu, India
oDepartment of Molecular Medicine and Haemotology, School of Pathology, Faculty of Health Science, University of Witwatersrand, Johannesburg, South Africa.
Correspondence to Lara Vojnov, PhD, World Health Organization, Avenue Appia 20. Geneva, Switzerland. Tel: +41 22 791 21 11; e-mail: email@example.com
Received 28 March, 2019
Revised 7 May, 2019
Accepted 17 May, 2019