Cost-effective analysis of different algorithms for the diagnosis of hepatitis C virus infection

A.M.E.C Barreto,M.A.O Bellesa,K Takei,C.C Barreto,A.S Nishiya,N.A Salles,Sabino E.C,D.F Chamone

doi:10.1590/s0100-879x2008005000004

Abstract

We compared the cost-benefit of two algorithms, recently proposed by the Centers for Disease Control and Prevention, USA, with the conventional one, the most appropriate for the diagnosis of hepatitis C virus (HCV) infection in the Brazilian population. Serum samples were obtained from 517 ELISA-positive or -inconclusive blood donors who had returned to Fundação Pró-Sangue/Hemocentro de São Paulo to confirm previous results. Algorithm A was based on signal-to-cut-off (s/co) ratio of ELISA anti-HCV samples that show s/co ratio > or =95% concordance with immunoblot (IB) positivity. For algorithm B, reflex nucleic acid amplification testing by PCR was required for ELISA-positive or -inconclusive samples and IB for PCR-negative samples. For algorithm C, all positive or inconclusive ELISA samples were submitted to IB. We observed a similar rate of positive results with the three algorithms: 287, 287, and 285 for A, B, and C, respectively, and 283 were concordant with one another. Indeterminate results from algorithms A and C were elucidated by PCR (expanded algorithm) which detected two more positive samples. The estimated cost of algorithms A and B was US$21,299.39 and US$32,397.40, respectively, which were 43.5 and 14.0% more economic than C (US$37,673.79). The cost can vary according to the technique used. We conclude that both algorithms A and B are suitable for diagnosing HCV infection in the Brazilian population. Furthermore, algorithm A is the more practical and economical one since it requires supplemental tests for only 54% of the samples. Algorithm B provides early information about the presence of viremia.

Highlights

In 1989 the Food and Drug Administration (FDA, USA) licensed the first antibody detection test for hepatitis C virus (HCV) using the c100-3 protein as antigen [1,2]
For algorithm A, the cut-off ratio ≥6 for enzyme-linked immunosorbent assays (ELISA)-positive samples agreed with IB-positive results in 99.2% of the cases, underscoring its ability to accurately predict true antibody-positive results
In samples with strong ELISApositive results (s/co ratio >50) HCV RNA was detected in 93.6% of the cases

Summary

Introduction

In 1989 the Food and Drug Administration (FDA, USA) licensed the first antibody detection test for hepatitis C virus (HCV) using the c100-3 protein as antigen [1,2]. Since new generations of anti-HCV tests have been introduced for laboratory diagnosis and these have been widely used in the serological screening of infected symptomatic or asymptomatic individuals. Second- or third-generation enzyme-linked immunosorbent assays (ELISA) are commercially available. These tests detect antibodies against one or more of the several recombinant or synthetic peptides produced by genes from different regions of the HCV genome. The first-generation tests detect antibodies with a sensitivity of 70 to 80% when applied to populations with a high prevalence of HCV infection, presenting an immunological window of 4 to 6 months [3]. The second- and third-generation tests have a high sensitivity of ~99.8% and an immunological window reduced to approximately 10 weeks when compared to the

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Conclusion