Hepatitis C viremia patterns in incident hepatitis C infection and one year later in 150 prospectively tested persons who inject drugs.
OBJECTIVE
To assess HCV viremia levels just before, during and one year after anti-HCV seroconversion in people who inject drugs (PWID).


METHODS
PWID enrolling into a needle exchange program in Malmö, Sweden, 1997-2005 constituted the source population. Sera were obtained at enrolment and at approximately 3-4 monthly intervals afterwards, and were initially tested for anti-HIV, HBsAg/anti-HBc and anti-HCV and thereafter for markers previously negative. Seroconversion to anti-HCV had occurred during the study period in 186 out of 332 seronegative subjects. In these anti-HCV seroconverters, quantitative HCV RNA PCR was retrospectively performed on frozen sera to determine viremia levels in the last anti-HCV negative, the first anti-HCV positive and in one year follow-up samples.


RESULTS
Among 150 subjects seroconverting to anti-HCV with samples available from all three defined time-points, eight different patterns of viremia were observed. Spontaneous clearance at one year was noted in 48 cases (32%) and was associated with female gender (p = 0.03, CI 0.17-1.00). In 13 cases HCV-RNA was not detected in any study sample. Among 61 subjects with pre-seroconversion viremia, viral load was significantly higher in the pre-seroconversion samples compared to subsequent samples. For the whole group, viral load declined to undetectable levels at seroconversion in 28% of cases (but with recurrent viremia in 15%).


CONCLUSIONS
Different patterns of HCV RNA kinetics were observed among PWID with documented seroconversion to anti-HCV. The frequently observed absence of detectable HCV RNA in the first anti-HCV positive sample (irrespective of subsequent viremia) demonstrates the importance of repeated sampling and RNA testing for determination of the outcome of acute infection.
Infectious Disease Unit, Division of Clinical Sciences, Lund University, Malmö, Sweden.
Marianne
M
Alanko Blomé
Infectious Disease Unit, Division of Clinical Sciences, Lund University, Malmö, Sweden.
Per
P
Björkman
Department of Clinical Microbiology, Division of Laboratory Sciences, Lund University, Malmö, Sweden.
Vilma
V
Molnegren
Medical Statistics and Epidemiology Unit, Research and Development Centre Skåne, Lund, Sweden.
Peter
P
Höglund
Department of Clinical Microbiology, Division of Laboratory Sciences, Lund University, Malmö, Sweden.
Anders
A
Widell
D000328:Adult; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics; D006526:Hepatitis C / Q000453:epidemiology / Q000821:virology*; D018937:Hepatitis C Antibodies / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018671:Needle-Exchange Programs; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012367:RNA, Viral / Q000097:blood*; D012189:Retrospective Studies; D015819:Substance Abuse, Intravenous / Q000097:blood*; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D019562:Viral Load; D014766:Viremia / Q000097:blood*; D055815:Young Adult
D018937:Hepatitis C Antibodies; D012367:RNA, Viral