Table 1.
Summary of Inclusion and Study Procedures Applicable to Study Analysis
| Cohort Name | City | Sample Size | Inclusion Criteria | No. of Sites | Recruitment Method(s) | Enrollment Perioda | Follow-up Interval for Serologyb |
|---|---|---|---|---|---|---|---|
| Amsterdam Cohort Studies (ACS) | Amsterdam | 48 | Active drug users (both PWID and non-PWID) using hard drugs at least 3 times/wk; ≥18 y of age; HIV negative and anti-HCV negative | 1 | Community-based outreach; open enrollment | 1984–present | 4-mo intervals (until 2003) then 6-mo intervals |
| Baltimore Before and After Acute Study in Hepatitis (BBAASH)c | Baltimore | 288 | Active PWID aged 18–65 y; anti-HCV negative | 1 | Community-based outreach; open enrollment | 1996–present | Monthly |
| Networks Study (N2) | Melbourne | 199 | Injection drug use in past 6 mo; ≥18 years of age; anti-HCV negative | 6 | Community- based outreach and respondent-driven sampling; open enrollment | 2005–2012 | 3-mo intervals |
| St Luc Cohort (HEPCO) | Montreal | 244 | Injection drug use in past 6 mo; ≥14 y of age; anti-HCV negative | 1 | Community-based outreach; open enrollment | 2004–present | 3–6-mo intervals |
| The UFO Study (UFO) | San Francisco | 398 | Injection drug use in past mo; <30 y of age at enrollment; anti-HCV negative | 1 | Community-based outreach; open enrollment | 2000–present | Monthly |
| Hepatitis C Virus Cohort (CU) | Sydney | 257 | Injection drug use within the past 6 mo; anti-HCV negative | 3 | Community-based outreach; open enrollment | 1999–2002 | 3–6-mo intervals |
| Hepatitis C Incidence and Transmission Study- Community (HITS-c) | Sydney | 134 | Injection drug use within past 12 mo; ≥16 y of age; anti- HCV negative | 5 | Community-based outreach; open enrollment | 2008–2012 | 3-, 6-, 9-, 12-, 15-, 18-, 24-mo intervals |
All cohorts enrolled participants prospectively.
Abbreviations: anti-HCV, hepatitis C virus antibody; HCV, hepatitis C virus; HIV, human immunodeficiency virus; PWID, people who inject drugs.
aAs of March 2015.
bAntibody and RNA testing were performed at the time of acute HCV detection. Anti-HCV testing was performed using the following assays: HCV enzyme immunoassay (EIA) 2.0 (Abbott Laboratories, Abbott Park, Illinois), EIA-3 (Ortho Clinical Diagnostics, Raritan, New Jersey), or Abbott Architect anti-HCV. Very little difference in antibody detection has been demonstrated between HCV EIA 2.0 and 3.0 [18]. Qualitative HCV RNA testing was performed using the following assays: Versant TMA (Bayer, Australia; <10 IU/mL), COBAS AmpliPrep/COBAS TaqMan (Roche, Branchburg, New Jersey; <15 IU/mL), COBAS Amplicor HCV Test v2.0 (Roche Diagnostics, Mannheim, Germany; <50 IU/mL), or discriminatory HCV transcription-mediated amplification component of the Procleix HIV-1/HCV (Gen-Probe, San Diego, California; <12 copies/mL). Quantitative HCV RNA testing was performed using the Versant HCV RNA 3.0 (Bayer; <615 IU/mL), COBAS Amplicor HCV Monitor 2.0 (Roche Diagnostics; <600 IU/mL), COBAS AmpliPrep/COBAS TaqMan (Roche; <15 IU/mL), or an in-house polymerase chain reaction (<1000 IU/mL).
cBBAASH recruits and monitors young PWID for HCV infection, with a focus on serological data to assess the clinical characteristics of acute infection and reinfection. Because research goals focus on understanding questions related to immunology and virology, behavioral data were not systematically collected between 2000 and 2012. The BBAASH data server was compromised in 2005, leading to the loss of data on age and biological sex for some participants. Investigators preformed genome-wide association studies to obtain sex for participants who acquired HCV infection, but because age is not a genetic trait, age information was not recovered.