In‐field evaluation of Xpert® HCV viral load Fingerstick assay in people who inject drugs in Tanzania

Abstract

Background Although novel hepatitis C virus (HCV) RNA point‐of‐care technology has the potential to enhance the diagnosis in resource‐limited settings, very little real‐world validation of their utility exists. We evaluate the performance of HCV RNA quantification using the Xpert® HCV viral load Fingerstick assay (Xpert® HCV VL Fingerstick assay) as compared to the World Health Organisation pre‐qualified plasma Xpert® HCV VL assay among people who inject drugs (PWID) attending an opioid agonist therapy (OAT) clinic in Dar‐es‐Salaam, Tanzania. Methods Between December 2018 and February 2019, consecutive HCV seropositive PWID attending the OAT clinic provided paired venous and Fingerstick samples for HCV RNA quantification. These were processed onsite using the GeneXpert® platform located at the Central tuberculosis reference laboratory. Results A total of 208 out of 220 anti‐HCV‐positive participants recruited (94.5%) had a valid Xpert® HCV VL result available; 126 (61%; 95% CI 53.8‐67.0) had detectable and quantifiable HCV RNA. About 188 (85%) participants had paired plasma and Fingerstick whole blood samples; the sensitivity and specificity for the quantification of HCV RNA levels were 99.1% and 98.7% respectively. There was an excellent correlation (R2 = .95) and concordance (mean difference 0.13 IU/mL, (95% CI −0.9 to 0.16 IU/mL) in HCV RNA levels between plasma samples and Fingerstick samples. Conclusion This study found excellent performance of the Xpert® HCV VL Fingerstick assay for HCV RNA detection and quantification in an African‐field setting. Its clinical utility represents an important watershed in overcoming existing challenges to HCV diagnosis, which should play a crucial role in HCV elimination in Africa.

Evaluation of true point of care molecular assay using fingerstick capillary whole blood for diagnosis of hepatitis C infection

“…In the present study, despite the collection of specimens by trained phlebotomists such errors were observed. Similar errors varying from 1-20 % had also been reported previously [9,10]. With our experience, a slightly deeper prick led to sufficient volume to be collected, thereby minimizing error.…”

“…The results are in concordance with a previous published study by Lamoury et al ., who also reported 100 % sensitivity and specificity [9]. A recent study conducted on people who inject drugs in Tanzania recorded 99.1 % sensitivity and 98.7 % specificity [10]. Unlike previous studies, the present study also evaluated performance using different sample types, i.e.…”

Injecting network structure determines the most efficient strategy to achieve Hepatitis C elimination in people who inject drugs

“…If this structure is the closest to ‘real‐world’ networks then the TasP effects of targeting HCV treatment at individuals with the largest numbers of injecting partnerships may have been underestimated. Such an approach is practically possible by engaging PWID with HCV treatment via peer‐led referral, 33 and the increasing availability of point of care RNA testing will support monitoring for reinfection in high risk PWID 34,35 …”

Time To Complete hepatitis C Cascade of Care Among Patients Identified During Mass Screening Campaigns in Rural Rwanda: A Retrospective Cohort Study

“…The second uses GeneXpert to provide point-of-care viral load testing. Similar applications of GeneXpert have achieved success in HIV programs in limited-resource settings, as they allow patients to receive viral load results on the same day as sample collection (19), and have been successfully used in HCV pilot programs in Egypt (29), Indonesia (30), and Tanzania (31). Given that HCV GeneXpert is WHO pre-quali ed for HCV viral load testing, it provides an opportunity for improving HCV patients monitoring and would also allow for integrated multi-disease testing platforms (32).…”