The current results indicate a high level of HEV endemicity throughout Poland compared with other countries. There is an urgent need to consider the protection of recipients of blood components against transfusion-transmitted HEV infection.

Background Since the introduction of nucleic acid testing (NAT) for routine blood donor screening, hepatitis C virus (HCV) RNA-only detection rates reported from Poland have been higher than in most other European countries. Methods To examine the factors likely contribute to these window-period donations, we conducted a case-control study among 47 recently HCV-infected blood donors, who gave blood between July 2002 and June 2014, with 141 controls matched by age, gender and donation dates. Firth-corrected conditional logistic regression models were fitted to estimate adjusted odds ratios (AORs) and 95% confidence intervals (CIs). Adjusted population attributable fractions (PAF) were calculated, based on the distribution of exposure among the cases. Results In a multivariate analysis, recent exposures in health care environments not routinely ascertained through pre-donation questionnaires, were strongly associated with recently-acquired HCV infection. These exposures included minor medical procedures and dental procedures in the preceding 6 months, AOR = 5.77 (CI = 2.01, 18.53). More important, however, based on PAF were behavioral deferrable risks that went unreported at the time of donation, such as high-risk sexual behaviors in the preceding 6 months (PAF=34%), or lifetime histories of drug use (PAF=28%). Conclusions This study raises questions about the effectiveness of deferral policy in excluding high-risk individuals. In addition, it provides further evidence supporting short, temporal deferrals for small medical procedures and dental treatments in Poland.

Hepatitis C virus (HCV) is characterized by high genetic variability, which is manifested both at the inter-host and intra-host levels. However, its role in the clinical course of infection is less obvious. The aim of the present study was to determine the genetic variability of HCV HVR1 (hypervariable region 1) of genotype 1b and 3 in plasma of blood donors in the early seronegative stage of infection (HCV-RNA+, anti-HCV−) and in samples from chronically infected patients using next-generation sequencing. Sequencing errors were corrected, and haplotypes inferred using the ShoRAH software. Genetic diversity parameters (intra-host number of variants, number of nucleotide substitutions and diversity per site) were assessed by DNA SP and MEGA. During the early infection, the number of variants were significantly lower in subjects infected with genotype 3 than with genotype 1b (p < 0.02). Similarly, intra-host number of variants, number of nucleotide substitutions and diversity per site were lower in genotype 3 chronic infection (p < 0.0005). In addition, early infection was characterized by significantly lower HVR1 variability values (p < 0.04) when compared to chronic infection for both genotypes. It seems that the observed differences in HVR1 variability represent an inherent property of particular viral genotypes.

The infection with more than one hepatitis C virus (HCV) genotype especially in subjects with a high risk of multiple HCV exposures has been demonstrated. The role of HCV mixed-genotype infection in viral persistence and treatment effect is not fully understood. The prevalence of such infection varies greatly depending on the technique used for genotype determination and studied population. Next-generation sequencing (NGS) which is suitable for extensive analysis of complex viral populations is a method of choice for studying mixed infections. The aim of the present study was to determine the prevalence of mixed-genotype HCV infections in the Polish seronegative, HCV-RNA-positive blood donors (n = 76). Two-step PCR was used for amplification of 5'-UTR of HCV. Using pyrosequencing altogether, 381,063 reads were obtained. The raw reads were trimmed and subjected to similarity analysis against the entire unfiltered NCBI nt database. Results obtained from NGS were compared with the standard genotyping. One (1.3%) mixed-genotype [3a, 2989 reads (94.8%); 1b, 164 reads (5.2%)] infection was found in a sample diagnosed as genotype 3a only by routine testing. Two samples were identified with different genotypes, compared to routine testing. In conclusion, NGS is a sensitive method for HCV genotyping. The prevalence of mixed-genotype HCV infections in blood donors is low.

Background In Poland, hepatitis A virus (HAV) RNA screening was performed in plasma for fractionation usually immediately before shipment. Objective Our goal was to study epidemiology, rate of transfusion transmitted HAV during epidemic (2017–2019), and viral characteristics of infected plasma donors. Study Design and Methods HAV RNA was tested in 1,866,590 donations from 1,210,423 donors using RT‐PCR in mini pools of 96 (MP96) or TMA in MP16. Virological characteristics included RNA level (RL), antibody testing, and sequencing. Results Twenty‐one HAV infections were identified (1.13/100,000 donations; 95% confidence interval [95% CI]: 0.74–1.72) and (1.73/100,000 donors; 95% CI: 1.35–2.65). The Blood Transfusion Centers were also informed about three donors, who were hospitalized for hepatitis A soon after their blood donation. In addition, we identified a donor, who had reactive result for HAV after receiving HAV vaccination. He tested positive twice 10 days after receiving the first and the second dose. The highest RL was 16 million IU/ml, mean 1,706,905 IU/ml, and median 220 IU/ml. The longest detectable RL lasted for 113 days. HAV‐infected donors were seronegative (36%) or IgM positive (64%). We followed up on 12 HAV contaminated blood components issued for transfusion. In two out of seven identified patients viral transmission was confirmed (28.6%). Conclusion Based on our results, we propose a 6 month deferral after HAV infection and 14 days post HAV vaccination. The infectivity rate was below 30%. The HAV RNA testing could be considered as an additional safeguard against HAV transmission at the time of increased incidence of HAV infections in the general population.