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.

Hepatitis B virus (HBV) genotypes have distinct geographical distributions and influence severity of clinical outcome and response to antiviral therapies. HBV polymorphism in HBV surface antigen (HBsAg) positive first time blood donors from Poland was examined. HBV serological markers and HBV DNA were tested in 170 samples. Whole genome (n = 53) or specific region sequences: pre-S/S and basic core promoter/precore (BCP/PC) region (91 and 154 samples, respectively) were phylogenetically analyzed. The median age of infected donors was 21 years. Anti-HBs, anti-HBe and hepatitis B e antigen were detected in 5%, 92.4% and 10.5% of tested donors, respectively. The HBV DNA load ranged between unquantifiable and 3.1 x 10(10) IU/mL (median: 4.10 x 10(3) IU/mL). Genotypes A2 (81.2%) and D (18.8%) co-circulated. Phylogenetic analyses revealed differences between the genotypes. Viral load and level of HBsAg tended to be lower in genotype D. The median HBsAg/HBV DNA ratio expressed in IU/mL was one for both genotypes, but very low or very high ratios appeared more frequent in genotype D infections. Higher amino acid variability in the surface proteins (median: 4%vs 1.5%; P = 0.01) and in the major hydrophilic region was observed in genotype D (P = 0.01). BCP/PC region analysis revealed the double mutation 1762T/1764A in 49/125 (39.2%) genotype A2 and 6/29 (20.7%) genotype D strains (P = 0.08). Mutations in PC and BCP regions correlated neither with HBsAg nor HBV DNA levels. HBV genotype A2 is dominant in HBsAg positive donors in Poland. Minority genotype D strains are significantly more substituted than genotype A2 strains potentially affecting the course of infection.

Parvovirus B19 (B19V) is divided into three genotypes. Genotypes 2 and 3 may cause diagnostic difficulties and their epidemiology is not well understood. In the present study the prevalence of B19V genotypes in patients with symptomatic infection in Poland was evaluated and the course of infection in patients infected with non-genotype 1 strains is described. Real-time PCR, able to detect all three genotypes of B19V was used to screen patient plasma samples. Sixty-nine, mainly acute-phase B19V DNA positive cases were identified in patients from hematological and obstetric/gynecological wards between 2004 and 2008. Thirty patients were studied in greater detail and genotyping was performed by analysis of the NS1/VP1u region. The majority of samples were genotype 1. However two (6.6%) strains were identified as genotype 2, associated with high viremia and identified in a kidney transplant recipient with anemia and a leukemia patient, following chemotherapy, with pancytopenia. A change of immunosuppression treatment in the former and treatment with intravenous immunoglobulin in latter, resulted in normalization of clinical parameters, and whilst viral loads fell, B19V DNA was still detectable. The kidney transplant recipient subsequently became pregnant with no clinical complications, although persistently infected with B19V genotype 2. This is the first description of symptomatic cases of genotype 2 B19V infection in Eastern Europe suggesting that acute infection, particularly among immunocompromised patients with these virus strains may be more prevalent than thought.

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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.

This study aims to characterize the intermediates, and the final product (FP) obtained during the production of human intramuscular hyperimmune gamma globulin anti-SARS-CoV-2 (hIHGG anti-SARS-CoV-2) and to determine its stability. Material and methods: hIHGG anti-SARS-CoV-2 was fractionated from 270 convalescent plasma donations with the Cohn method. Prior to fractionation, the plasma was inactivated (Theraflex MB Plasma). Samples were defined using enzyme immunoassays (EIA) for anti-S1, anti-RBD S1, and anti-N antibodies, and neutralization assays with SARS-CoV-2 (VN) and pseudoviruses (PVN, decorated with SARS-CoV-2 S protein). Results were expressed as a titer (EIA) or 50% of the neutralization titer (IC50) estimated in a four-parameter nonlinear regression model. Results: Concentration of anti-S1 antibodies in plasma was similar before and after inactivation. Following fractionation, the anti-S1, anti-RBD, and anti-N (total tests) titers in FP were concentrated approximately 15-fold from 1:4 to 1:63 (1800 BAU/mL), 7-fold from 1:111 to 1:802 and from 1:13 to 1:88, respectively. During production, the IgA (anti-S1) antibody titer was reduced to an undetectable level and the IgM (anti-RBD) titer from 1:115 to 1:24. The neutralizing antibodies (nAb) titer increased in both VN (from 1:40 to 1:160) and PVN (IC50 from 63 to 313). The concentration of specific IgG in the FP did not change significantly for 14 months. Conclusions: The hIHGG anti-SARS-CoV-2 was stable, with concentration up to approximately 15-fold nAb compared to the source plasma pool.

Extremely high viremia is observed during some viruses infection, especialy in immunocompromised patients. False negative results of Parvovirus B 19 DNA tests performed with real-time PCR in high viremic samples are reported. The way of fluorescence diagrams analysis and algorithm of positive result confirmation to exclude such phenomenon are proposed.

Nucleic acid testing (NAT) was implemented in Poland in 1999 for screening of plasma for fractionation and for all blood donors in 2002. To analyze seronegative NAT-positive samples representing hepatitis C virus (HCV) window-period (WP) in the years 2000 to 2016 and to determine infection outcome. We analyzed results of 17 502 739 donations screened in minipools (6-48) or individually. Index samples underwent viral load (VL) quantification, genotyping and Ag, and anti-HCV re-testing using chemiluminescence (CMIA), electrochemiluminescence (ECLIA), and fourth-generation enzyme-linked immunosorbent assay (IV EIA)assays. HCV-seronegative infections were identified in 126 donations (7.2/mln donations; 95% confidential intervals, 6.0-8.6). Frequency of NAT yields was decreasing over time. Of the initial 126 seronegative index cases 106 were retested: 32.1% were reactive in IV EIA, 11.3% in ECLIA, and 1.9% in CMIA. The lowest VL correlated with absent anti-HCV and HCV Ag, while VL was highest when the antigen was detectable and then it decreased when anti-HCV appeared at a level detectable by sensitive third generation tests while retesting. The proportion of genotype 1 was 38.9% in samples positive only for HCV RNA and 71.4% in samples that were anti-HCV reactive in re-testing. In parallel, genotype 3 frequency was 50% in the former group and 21% in the latter. NAT is an effective measure to limit HCV transmission by transfusion and IV EIA seems to have higher clinical sensitivity than ECLIA. Samples representing likely successive phases of early HCV infection were characterized by different genotype distribution probably due to very early elimination of genotype 3. K E Y W O R D S blood donors, clinical sensitivity, EIA assays, HCV, NAT yields ---