Abstract
Background. Sensitive methods are needed to estimate the population-level incidence of hepatitis C virus (HCV) infection. Methods. We developed an HCV immunoglobulin G (IgG) antibody avidity assay by modifying the Ortho 3.0 HCV enzyme-linked immunoassay and tested 997 serum or plasma samples from 568 people who inject drugs enrolled in prospective cohort studies. Avidity-based testing algorithms were evaluated by their (1) mean duration of recent infection (MDRI), defined as the average time an individual is identified as having been recently infected, according to a given algorithm; (2) false-recent rate, defined as the proportion of samples collected >2 years after HCV seroconversion that were misclassified as recent; (3) sample sizes needed to estimate incidence; and (4) power to detect a reduction in incidence between serial cross-sectional surveys. Results. A multiassay algorithm (defined as an avidity index of <30%, followed by HCV viremia detection) had an MDRI of 147 days (95% confidence interval [CI], 125-195 days), and the false-recent rates were 0.7% (95% CI,. 2%-1.8%) and 7.6% (95% CI, 4.2%-12.3%) among human immunodeficiency virus (HIV)-negative and HIV-positive persons, respectively. In various simulated high-risk populations, this algorithm required <1000 individuals to estimate incidence (relative standard error, 30%) and had >80% power to detect a 50% reduction in incidence. Conclusions. Avidity-based algorithms have the capacity to accurately estimate HCV infection incidence and rapidly assess the impact of public health efforts among high-risk populations. Efforts to optimize this method should be prioritized.
Original language | English (US) |
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Pages (from-to) | 344-352 |
Number of pages | 9 |
Journal | Journal of Infectious Diseases |
Volume | 214 |
Issue number | 3 |
DOIs | |
State | Published - Aug 1 2016 |
Keywords
- HCV
- HIV
- antibody response
- incidence testing
- people who inject drugs
- recent infection
- surveillance
ASJC Scopus subject areas
- Immunology and Allergy
- Infectious Diseases