Sabine Ritter

Background and Objectives: We estimated and compared the residual risks due to window‐period donations for pooled and apheresis platelets in Germany using a modification of a previously described statistical model. This model directly utilizes the reported interdonation intervals before a positive donation and reflects in this aspect the look‐back procedures used in haemovigilance.Materials and Methods: Data from the German National Blood Donor Surveillance System for the years 2006–2012, including reports about donations from repeat donors with confirmed positive test results for HIV, HCV and HBV, were used to estimate the risk of undetected infectious units for both pooled and apheresis platelets.Results: Demographics of whole‐blood and apheresis donors differed in age, gender, catchment area and interdonation interval. These differences impact on the prevalence and incidence of transfusion relevant infections and consequently the residual risk. The estimates for the residual risks for pooled and apheresis platelets were comparable. For HIV, there was no significant difference, for HCV apheresis platelets had a lower residual risk, whereas pooled platelets had a lower risk for undetected HBV infections.Conclusion: These findings do not support calls for a shift to an apheresis platelets‐only policy in Germany.

Seit 2006 erhebt das Robert Koch-Institut im Rahmen der Blutspendersurveillance neben infektionsepidemiologischen Daten auch Informationen zur Anzahl der Spender in Deutschland. Die vorliegende Publikation beschreibt die Demografie der Spenderpopulationen für Vollblut, Plasma und Zytapherese des Jahres 2010. Veränderungen in der Altersstruktur und im Spendeverhalten und deren Auswirkung auf das Spendenaufkommen werden vergleichend zur Ersterhebung von 2006 dargestellt. Die Anzahl der Personen im spendefähigen Alter nahm von 2006 bis 2010 um mehr als 2% ab. Dennoch stieg die Zahl der Neu- bzw. Mehrfachspender für Vollblut um 8 bzw. 7%. Im gleichen Zeitraum nahm die Zahl der Neuspender von Plasma um 23%, die der Mehrfachspender sogar um 41% zu. Im Jahr 2010 waren über 4,3% der Bevölkerung zwischen 18 und 68 Jahren wiederholt als Vollblutspender und 0,4% als Apheresespender aktiv. Gegenüber dem Jahr 2006 nahm der Spenderanteil an der Allgemeinbevölkerung insbesondere bei den 18- bis 24-Jährigen deutlich zu. Die Spendehäufigkeit variierte abhängig von Spendenart, Geschlecht und Alter der Spender. Im Durchschnitt lag sie für Vollblut bei 1,9, für Plasmapheresen bei 12,5 und für Zytapheresen bei 5,0 Spenden im Jahr. Gegenüber 2006 stieg die Zahl der pro Spender geleisteten Spenden für Apheresen deutlich an, v. a. bei älteren Spendern. Die Spendehäufigkeit der Vollblutspender blieb nahezu unverändert. Durch die stärkere Rekrutierung von Neuspendern und die verbesserte Pflege und Reaktivierung erfahrener Spender konnte das Spendenaufkommen von Vollblut und Apheresen in Deutschland ausgebaut werden. The Robert Koch Institute collects and evaluates nationwide data on the incidence and prevalence of transfusion-relevant infections among blood and plasma donors in Germany. Since 2006 data not only on the number of donations tested but also on the number of the respective donors have become available. The demographic profile and donation frequencies of German whole blood, plasma and platelet donors in 2010 and the percentages among the general population are described and compared to data from 2006. Although the general population eligible to donate blood is on the decline since 2003, with a loss of 2% between 2006 and 2010, this has not led to a decrease in the number of blood donors and donations. Instead, the number of new and repeat whole blood donors increased by 8% and 7%, respectively. At the same time, the number of new plasma donors grew by 23%, that of repeat plasma donors by 41%. In 2010 more than 4.3% of the population aged 18–68 years was active as repeat whole blood donors; 0.4% repeatedly donated plasma or platelets. Since 2006 the percentage of donors among the general population increased significantly, especially among the youngest age group (18–24 years). Donation frequency varied depending on donor age and sex, with an average of 1.9 per year for whole blood donations, 12.5 for plasmapheresis and 5.0 for plateletpheresis. While the donation frequency for whole blood remained unchanged since 2006, the frequency of apheresis donations increased, especially among older donors. By recruiting more new donors and retaining and reactivating existing ones more effectively, the number of whole blood and apheresis donations was augmented.

According to Article 22 of the Transfusion Act, the Robert Koch Institute collects and evaluates nationwide data on the prevalence and incidence of transfusion-relevant infections among blood and plasma donors in Germany. Due to revision of the Transfusion Act in 2005 not only the number of donations but also the number of donors has become available for analysis. Here we give a detailed account on the demographic profile and donation frequencies of German whole blood, plasma and platelet donors in 2006. Overall, 4 % of the German population eligible to donate were active as repeat whole blood donors in 2006; 0.3 % repeatedly donated plasma or platelets. Irrespective of the type of donation, the percentage of donors among the general population was highest among the youngest age group (18 to 24 years). While the age distribution of whole blood repeat donors roughly resembled that of the general population, with the greatest number among those aged 35 to 44, younger age groups were overrepresented among repeat plasma donors. Donation frequency varied depending on donor age and sex, with an average of 1.9 per year for whole blood donations, 11.9 for plasmapheresis and 4.0 for plateletpheresis. With the exception of the latter, men donated more frequently than women. For both sexes, donation frequency increased with age. Detailed knowledge of the demographic profile and changes in the composition of donor populations are essential for planning adequate blood supply. The data presented may serve as reference for assessing the consequences of measures that affect the number of donors and/or donations (for example changing deferral criteria) in Germany.

Blood and plasma donations in Germany are collected by several institutions, namely the German Red Cross, community and hospital-based blood services, private blood centres, commercial plasma donation sites and transfusion services of the army. All blood donation centres are required to report quarterly data on infection markers to the Robert Koch Institute, thus providing current and accurate epidemiological data. The prevalence and incidence of relevant viral infections are low in the blood donor population in Germany, with a decreasing trend for hepatitis C infections in new and repeat donors since 1997. The implementation of mandatory nucleic acid amplification technique (NAT) testing for hepatitis C virus (HCV) in 1999 has markedly improved transfusion safety. HIV-NAT became mandatory in 2004 but was done voluntarily by the majority of the blood donation services before then. The potential benefit of hepatitis B virus (HBV) minipool NAT is not as clear because chronic HBV carriers with very low virus levels might donate unidentified. The residual risk of an infectious window period donation inadvertently entering the blood supply can be estimated using a mathematic model which multiplies the incidence rate by the number of days during which an infection may be present but not detectable, i.e. the length of the window period. The risk of an undetected infection without NAT testing was estimated to be 1 in 2 770 000 for HIV, 1 in 670 000 for HCV and 1 in 230 000 for HBV in 2001/2002. This contrasts with 1 in 5 540 000 for HIV, 1 in 4 400 000 for HCV and 1 in 620 000 for HBV with minipool NAT testing. This demonstrates that NAT testing can further reduce the already very small risk of infectious donations entering the blood supply.