Wenli Fan

Current incidence and estimated residual risk of transfusion-transmitted infections in donations made to Canadian Blood Services

BACKGROUND: New testing methods such as nucleic acid amplification testing (NAT) and chemiluminescent serologic assays have been introduced, more precise estimates for infectious window periods are available, and a new method for estimating the residual risk (RR) of transfusion‐transmitted infections (TTIs) has been developed. Thus, available RR estimates for Canada need to be updated.

Current incidence and residual risk of HIV, HBV and HCV at Canadian Blood Services

Estimates of the viral residual risk should be updated to reflect current incidence of infection in blood donors. Incidence rates were estimated for allogeneic whole‐blood donations made to Canadian Blood Services from 2006 to 2009 based on transmissible disease conversions of repeat donations within a 3‐year period. Residual risk was estimated as the incidence multiplied by the window period. The residual risk of HIV was 1 per 8 million donations, HCV 1 per 6·7 million donations and HBV 1 per 1·7 million donations. The residual risk remains low and has decreased for HCV since our previous estimates due to reduced incidence.

Hepatitis B virus DNA–positive, hepatitis B surface antigen–negative blood donations intercepted by anti‐hepatitis B core antigen testing: the Canadian Blood Services experience

BACKGROUND: The benefit of introducing anti‐hepatitis B core antigen (HBc) screening for intercepting potentially infectious donations missed by hepatitis B surface antigen (HBsAg) screening in Canada was studied.

Declining hepatitis C rates in first‐time blood donors: insight from surveillance and case‐control risk factor studies

BACKGROUND: Hepatitis C virus (HCV) rates have decreased steadily in first‐time donors in Canada since testing was implemented but reasons are unclear. A description of factors that may have played a role in this decline is reported.

Epidemiology of hepatitis B in Canadian blood donors

BACKGROUND: The residual risk of hepatitis B is higher than for other markers such as human immunodeficiency virus and hepatitis C virus in nonendemic countries. Evaluating the potential for further risk reduction requires a better understanding of the relationship between donor selection criteria, immigration from endemic countries, and public health vaccination strategies.

Predictive ability of sequential surveys in determining donor loss from increasingly stringent variant Creutzfeldt-Jakob disease deferral policies

BACKGROUND:  Predonation screening questions about travel increase the safety of the blood supply from diseases such as variant Creutzfeldt‐Jakob disease (vCJD) and malaria. This study examines the ability of sequential surveys to predict actual travel deferrals and the operational validity of travel questions.

Face-to-face interviewing in predonation screening: lack of effect on detected human immunodeficiency virus and hepatitis C virus infections

BACKGROUND: Predonation screening has become more elaborate over the years, while human immunodeficiency virus (HIV)‐ and hepatitis C virus (HCV)‐positive donations have declined. The impact of face‐to‐face interviewing and of the format of the Donor Health Assessment Questionnaire (DHAQ) have not been evaluated.

Reassessment of deferrals for tattooing and piercing

BACKGROUND: In August 2005, the Canadian Blood Services decreased the deferral period for tattooing and ear or body piercing from 12 to 6 months. This study assessed the impact of this change on blood safety and availability.

Assessment of a travel question to identify donors with risk of Trypanosoma cruzi: operational validity and field testing

BACKGROUND: Because Trypanosoma cruzi (T. cruzi) infection in Canada and the United States is largely contracted in endemic countries, targeted testing of blood donors with risk travel may improve safety. The operational validity of a travel question suitable for donor screening was tested, and it was field‐tested.

Evaluation of the confidential unit exclusion form: the Canadian Blood Services experience

Background  In the mid‐1980s, confidential unit exclusion (CUE) was implemented to permit donors unwilling to admit risk factors in screening to exclude their donation from transfusion. With changes in donor behaviour, epidemiology of disease and improvements in testing, many blood establishments have stopped using it. We evaluated its benefit in Canada, and reported its utility in predicting transmissible‐disease (TD) and high‐risk behaviour.