A revised method for estimating hepatitis B virus transfusion residual risk based on antibody to hepatitis B core antigen incident cases.
BACKGROUND
To take into account the transient nature of hepatitis B virus (HBV) antigenemia, the calculation of HBV residual risk (RR), based on the incidence/window period model, is adjusted by a correction factor that adds uncertainty to the RR estimates.


METHODS
This new method to estimate the RR for HBV is a weighted sum of the RR derived from hepatitis B surface antigen (HBsAg) incident cases and the one derived from antibody hepatitis B core antigen (HBc) incident cases. An anti-HBc incident case was defined as a donation from a blood donor who had made at least one anti-HBc-negative donation followed by a donation that was found positive with two different assays within a 3-year period and positive for at least one of the following markers: 1) antibody to hepatitis B e antigen or hepatitis B e antigen, 2) anti-HBc immunoglobulin M, 3) HBV DNA, 4) hepatitis B surface antibody without HBV vaccination history, or 5) HBV DNA retrospectively found in the previous donation. Five overlapping 3-year study periods between 2000 and 2006 were analyzed.


RESULTS
The HBV RR estimated with the classical method ranged from 1.51 (2000-2002) to 0.69 per million donations in 2004 through 2006 with a decrease in 2002 through 2004 due to only two HBsAg incident cases reported in this period. By applying the revised model, the HBV RR ranged from 1.06 (2000-2002) to 0.49 per million donations (2004-2006), with a regular decrease.


CONCLUSIONS
The new presented model provides HBV RR estimates that do not statistically differ from those obtained with the classical model; however, it provides more accurate data, especially in low endemic areas where the HBsAg incidence is low.
Laperche
Syria
S
Centre National de Référence pour les hépatites B et C en transfusion, Département des Agents Transmissibles par le Sang, Institut National de la Transfusion Sanguine, Paris, France. slaperche@ints.fr
Maniez
Michèle
M
Barlet
Valérie
V
El Ghouzzi
Marie-Hélène
MH
Le Vacon
Françoise
F
Levayer
Thierry
T
Lunel
Françoise
F
Morel
Pascal
P
Mouillot
Laurence
L
Piquet
Yves
Y
Pillonel
Josiane
J
D000328:Adult; D000465:Algorithms; D001782:Blood Donors; D004279:DNA, Viral / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D006509:Hepatitis B / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology / Q000635:transmission*; D006510:Hepatitis B Antibodies / Q000097:blood*; D006512:Hepatitis B Core Antigens / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006513:Hepatitis B e Antigens / Q000097:blood; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D015994:Incidence; D008297:Male; D008954:Models, Biological; D012189:Retrospective Studies; D012306:Risk; D065227:Transfusion Reaction; D014766:Viremia / Q000175:diagnosis / Q000276:immunology*
D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; D007075:Immunoglobulin M