Relative efficacy of nucleic acid amplification testing and serologic screening in preventing hepatitis C virus transmission risk in seven international regions.
BACKGROUND
The relative contribution of serologic screening and nucleic acid testing (NAT) to prevent hepatitis C virus (HCV) transmission has not been rigorously addressed.


METHODS
Twenty-one blood organizations in seven geographical regions performing individual-donation (ID)-NAT in parallel with anti-HCV screening provided data from 10,897,105 donations to establish HCV infection rates in first-time, lapsed, and repeat donations. Screening efficacy was modeled for: anti-HCV alone, HCV antigen/antibody (combo), minipool (MP)-NAT in pools of 8 and 16 with anti-HCV, ID-NAT and anti-HCV, and ID-NAT alone. Probabilities of infectivity for red blood cell transfusions were estimated as 100% from window period (WP) and concordant HCV RNA/antibody-positive (concordantly positive [CP]) donations and 0.028% from anti-HCV-positive and RNA-negative probable resolved (PR) donations.


RESULTS
There were 5146 confirmed infections (30 WP, 3827 CP, and 1289 PR). Infection rates and transmission risks varied substantially across regions and by donation status. Residual risk with ID-NAT and serology screening was estimated at one in 250,000 in Egypt and at one in 10,000,000 in other regions combined; risk would increase to one in 7300 and one in 312,000, respectively, if NAT had not been performed. ID-NAT with or without anti-HCV testing showed higher efficacy than either MP-NAT or combo assays, particularly in lapsed or repeat donors in whom 99.2, 98.5, and 93.2% of infectious donations were estimated to be interdicted by these respective testing strategies.


CONCLUSIONS
The incremental efficacy of anti-HCV testing when ID- NAT screening is performed was minimal, particularly for screening lapsed and repeat donations.
Blood Systems Research Institute, San Francisco, California.
Roberta
R
Bruhn
Lelie Research, Paris, France.
Nico
N
Lelie
Blood Systems Research Institute, San Francisco, California.
Michael
M
Busch
University of British Columbia, Victoria, British Columbia, Canada.
Steven
S
Kleinman
D000349:Africa / Q000453:epidemiology; D001210:Asia, Southeastern / Q000453:epidemiology; D001782:Blood Donors / Q000706:statistics & numerical data*; D058731:Blood Safety; D046148:Donor Selection / Q000379:methods*; D017707:Erythrocyte Transfusion / Q000009:adverse effects; D005060:Europe / Q000453:epidemiology; D014943:Global Health; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology; D006526:Hepatitis C / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission; D018937:Hepatitis C Antibodies / Q000097:blood*; D018936:Hepatitis C Antigens / Q000097:blood*; D006801:Humans; D015994:Incidence; D008954:Models, Biological; D021141:Nucleic Acid Amplification Techniques; D044349:Oceania / Q000453:epidemiology; D012367:RNA, Viral / Q000097:blood*; D012306:Risk; D016036:Seroepidemiologic Studies; D012698:Serologic Tests; D019562:Viral Load; D014766:Viremia / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission
D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D012367:RNA, Viral