Background
Transfusion transmitted HEV infections pose a risk of serious illness especially to immunocompromised recipients. In Germany, screening of blood donations for HEV-RNA is mandatory since 2020 for all non-virus-inactivated packed red cells, platelet concentrates and plasma. A detection limit of 2000 IU/ml HEV-RNA must be ensured. This is the first nationwide analysis of HEV incidence in the German blood donor population.
Methods
Data from the national blood donor surveillance system were used to estimate sex, age and regional stratified incidences of acute asymptomatic HEV infections and compared to data from mandatory reports according to the Infection Protection Act on symptomatic infections.
Results
Altogether 3507 HEV infections were reported in 2020 in 3,437,039 donors (102/100,000 donors). Male donors were 1.8 times more affected than females (127 vs. 71/100,000). HEV incidence was twice as high in donors >44 yrs as in donors <25 yrs (150 vs 74/100,000). Regional differences were found with highest incidence in the state of Brandenburg (169/100,000) and lowest in Baden-Wurttemberg (74/100,000). Reported symptomatic infections showed a similar pattern but incidences were 20 to 30 times lower. The overall incidence was 5.2/100,000 in the general population (18-78 yrs) and was also age dependent (44 yrs: 2.5 vs. 6.5/100,000). The difference between males (6.0/100,000) and females (4.3/100,000) was less pronounced. The regional spread of infections among donors was also observed in symptomatic infections.
Conclusion
In 2020 1 in 1000 donors was detected positive for HEV RNA. This is a much larger incidence than any other infection tested for. According to recent viral load analyses [1, 2] the current obligatory test sensitivity could result in further 3000-10,000 undetected infections. While it is assumed that most are not infectious due to a low viral load, the large number of undetected infections may pose a residual risk of infectious donations that should not go unnoticed. Therefore, hemovigilance data should be carefully monitored to check whether the required sensitivity should be amended.
[1] Vollmer T, Diekmann J, Knabbe C, Dreier J. Hepatitis E virus blood donor NAT screening: as much as possible or as much as needed? Transfusion. 2019;59(2):612-22.
[2] Cordes AK, Goudeva L, Lütgehetmann M, Wenzel JJ, Behrendt P, Wedemeyer H, et al. Risk of transfusion-transmitted hepatitis E virus infection from pool-tested platelets and plasma. J Hepatol. 2022;76(1):46-52.
Offenlegung Interessenkonflikt:
The authors declare that they have no conflict of interests.
Invited talks abstract/summary