Dynamics of viremia in early hepatitis C virus infection.
BACKGROUND
It is important to characterize viral dynamics in early hepatitis C virus (HCV) infection to further our understanding of viral pathogenesis and the potential for secondary transmission in acute infection through blood transfusion or other routes.


METHODS
Serial units given by 77 source plasma donors who had evolved from HCV RNA-negative to HCV RNA-positive by nucleic acid amplification technology (NAT) screening with 512-unit pool-NAT or were followed from RNA detection to antibody conversion were tested by individual NAT and quantitative RNA assays.


RESULTS
During the ramp-up phase when exponential growth occurs, HCV viral load doubled every 10.8 hours (95% confidence interval [CI], 9.9-12.0). Intermittent viremia was observed before the ramp-up phase in 37 of 50 panels with the earliest detectable viremic bleed occurring 63 days before the estimated onset of ramp-up. The plateau phase or high-titer viremic period that occurs between ramp-up and seroconversion was estimated to last 56.3 days (95% CI, 44.8-67.8).


CONCLUSIONS
Intermittent low-level HCV viremia can occur as much as 2 months before the periods of exponential increase in viral load and the high-titer plateau-phase viremia that usually precede seroconversion. Animal inoculation studies are in progress to evaluate if transfusion of low-level viremic plasma can transmit HCV infection.
Glynn
Simone A
SA
Westat, Rockville, Maryland, USA.
Wright
David J
DJ
Kleinman
Steven H
SH
Hirschkorn
Dale
D
Tu
Yongling
Y
Heldebrant
Charles
C
Smith
Richard
R
Giachetti
Cristina
C
Gallarda
James
J
Busch
Michael P
MP
D001782:Blood Donors; D016174:Hepacivirus / Q000235:genetics* / Q000302:isolation & purification; D019698:Hepatitis C, Chronic / Q000097:blood / Q000175:diagnosis* / Q000635:transmission; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012367:RNA, Viral / Q000097:blood*; D012189:Retrospective Studies; D012698:Serologic Tests / Q000379:methods; D013997:Time Factors; D019562:Viral Load; D014766:Viremia / Q000097:blood / Q000175:diagnosis* / Q000635:transmission; D014779:Virus Replication
D012367:RNA, Viral