Hepatitis B virus vaccination of blood donors--what costs may be expected?

Current concepts in the prevention of pathogen transmission via blood/plasma-derived products for bleeding disorders

The pathogen safety of blood/plasma-derived products has historically been a subject of significant concern to the medical community. Measures such as donor selection and blood screening have contributed to increase the safety of these products, but pathogen transmission does still occur. Reasons for this include lack of sensitivity/specificity of current screening methods, lack of reliable screening tests for some pathogens (e.g. prions) and the fact that many potentially harmful infectious agents are not routinely screened for. Methods for the purification/inactivation of blood/plasma-derived products have been developed in order to further reduce the residual risk, but low concentrations of pathogens do not necessarily imply a low level of risk for the patient and so the overall challenge of minimising risk remains. This review aims to discuss the variable level of pathogenic risk and describes the current screening methods used to prevent/detect the presence of pathogens in blood/plasma-derived products.

Residual Risk of Hepatitis-B-Infected Blood Donations: Estimation Methods and Perspectives

Despite a considerable reduction of the risk of HBV-infected blood donation entering blood supply (residual risk) due to improved screening by HBV NAT in the developed countries, the bulk of the people with HBV living in the developing countries still needs to be screened by serologic tests such as HBsAg and anti-HBc. Many of these countries lack resources for implementing NAT and are likely to remain so in the next decade or longer, thus depending on the HBV residual risk monitoring based on serologic testing and corresponding estimation methods. This paper reviews main HBV residual risk findings worldwide and the methods based on serology used for their calculation with repeat donors, as well as their extension to the first-time donors. Two artificial datasets with high (4.36%) and low (0.48%) HBV prevalence were generated to test the performance of five methods: the original incidence/window-period model based solely on HBsAg, its modification by Soldan in 2003, the Müller-Breitkreutz model, the HBsAg yield model, and its extension to include anti-HBc seroconversions within a year. The last model was closest to the true values of residual risk and had smallest variation of the estimates in both high and low prevalence data. It may be used for residual risk evaluation in relatively small samples, such as regional blood banks data.

A cost-benefit analysis of blood donor vaccination as an alternative to additional DNA testing for reducing transfusion transmission of hepatitis B virus

A survey-based, cost-benefit analysis was performed comparing blood screening strategies with vaccination strategies for the reduction of transfusion transmission of HBV. 231 whole blood donors and 126 apheresis donors were eligible and completed a questionnaire detailing their donation habits. The cost-benefit analysis included current mandatory HBV testing (HbsAg+anti-Hbc, A1), A1 with additional nucleic acid testing (NAT) for minipool (A2) or individual donation testing (A3), as well as HBV vaccination strategies using time-dependant (B1) or titre dependent booster vaccination solely (B2), or B2 in addition to current mandatory testing procedures (B3). Different cost models were applied using a 5% rate of discount. Absolute costs for current mandatory testing procedures (A1) over 20 years in Germany were €1009 million. Additional NAT would lead to incremental costs of 43% (A2) or 339% (A3), respectively. Vaccination strategies B1 and B2 showed cost-reductions relative to A1 of 30% and 14%, respectively. The number of remaining HBV infections could be reduced from 360 (for A1) to 13, using vaccination, compared with 144 or 105 remaining infections for A2 or A3, respectively. Absolute cost per prevented infection is similar (€2.0 million) for A2 and B3. HBV vaccination offers the near-elimination of transfusion infections while representing a potential cost-reduction.

Epidemiological Data - an Important Part of the Hemovigilance System

Epidemiological data are essential for monitoring trends and outbreaks of infectious diseases in the general population. The reporting system pursuant to the Infection Protection Act in Germany results in a very good quality of timely nationwide data on all reportable diseases including those relevant for the blood supply: HIV, hepatitis C, hepatitis B and syphilis. Notifications of acute hepatitis B and first-time diagnosed hepatitis C infections in the general population showed a declining trend in the past years, but the number of reports of HIV and syphilis infections increased until 2007 especially among men who have sex with men. New preventive strategies should also address changes in sexual behavior. The specific surveillance of blood donors is an important part of the hemovigilance system. The highly effective donor selection process results in a small number of confirmed infections among donors in Germany. The surveillance data enable us to identify specific trends that might challenge blood safety like the increase in HIV infections among repeat donors. Specific evaluations are performed when needed. These additional studies can be used to modify guidelines or recommendations and to (re)evaluate the need for or the effect of further testing.