Rapid point-of-care (POC) testing for Hepatitis C antibodies in a very high prevalence setting: persons injecting drugs in Tallinn, Estonia

Abstract

Background: Between December 2018 and January of 2019, we evaluated the accuracy of the point-of-care Hepatitis C (HCV) antibody test (POC; OraQuick HCV) used at a community-based needle and syringe exchange program serving persons who inject drugs in Tallinn, Estonia.

Methods: We compared the results of screening for HCV antibodies by OraQuick (oral swab) and enzyme immunoassay (EIA; blood draw) and assessed test results implications in a high prevalence setting. Findings Of the 100 participants, 88 (88%) had reactive POC test results, and 93 were HCV antibody positive on EIA testing. Sensitivity, specificity and negative predictive value (NPV) for the POC assay with EIA as the relevant reference test were as follows: 94.6% (95% CI 90.0-99.2%), 100% and 58.3% (95% CI 30.4-86.2%). Of the 12 testing, HCV-negative with the POC only 7 (58.3%) were true negatives.

Conclusions: Oral swab rapid testing HCV screening in this nonclinical setting was sensitive and specific but had unacceptably low NPV. In high prevalence settings, POC tests with high sensitivity and that directly measure HCV RNA may be warranted.

Keywords: Estonia; HCV POC testing; HCV RNA testing; HCV antibody testing; HCV testing; PWID; Persons who inject drugs.

Fig. 1

Effect of assay sensitivity and seroprevalence on probability of misclassification (1-NPV: probability that a person who tests negative is truly seropositive)