A 36-year-old woman acquired severe human granulocytic anaplasmosis after blood transfusion following a cesarean section. Although intensive treatment with mechanical ventilation was needed, the ...patient had an excellent recovery. Disease caused by Anaplasma phagocytophilum infection was confirmed in 1 blood donor and in the transfusion recipient.
ObjectiveHBV infection by blood components is currently prevented in most developed countries by combining sensitive HBV surface antigen (HBsAg) assays, nucleic acid testing (NAT) and in a few of ...them antibodies against the HBV core antigen (anti-HBc) screening. HBV transmissions by blood components from three repeat donors tested negative for HBsAg and HBV DNA with a highly sensitive screening test (limit of detection (LOD): 3.4 IU/mL) were investigated.Design30 of the 47 recipients of components produced from these three donors were examined. Transfusion transmission was confirmed by phylogenetic analysis of viral sequences obtained from recipients and donors following viral particle concentration.Results9 of 31 (29%) recipients were infected: 7 infections were related to 200 mL of fresh frozen plasma and 2 infections to red blood cells containing 20 mL plasma. Transfusion transmission was confirmed by >99% identity of donor/recipient sequences in five cases, probable in three and possible in one. HBV active infection remained unsuspected for 24–57 months in three recipients. Five non-infected recipients carried anti-HBs when transfused. Six patients transfused with platelet concentrates treated with a pathogen reduction method were not infected. These data enabled to revise previous estimate of the minimal infectious dose from approximately 100 to 16 copies (or 3 IU) of HBV DNA.ConclusionsHBV transfusion transmission from occult HBV infection carrying extremely low viral loads is related to plasma volume transfused and possibly prevented by anti-HBs. HBV blood safety could be further improved by either anti-HBc screening, HBV DNA NAT with a LOD of 0.8 copies/mL (0.15 IU/mL) or pathogen reduction of blood components.
The variability in the immune response modulated by HLA alleles may be an important factor for the induction of the protective effect of HBsAg vaccines. We present here the analysis of HLA-DRB1, DQB1 ...and DQA1 alleles and their combinations in the group of 36 individuals with poor humoral immmune response to HBsAg vaccination. Comparison with the control group, consisted of 60 randomly choosen healthy subjects, revealed that the DRB1*1601, DQB1*0502, DQA1*0102 haplotype is overrepresented in the group of hyporesponders and may therefore be regarded as a factor influencing poor antibody responsiveness. We observed that after revaccination two of three individuals who failed to develop anti-HBs antibodies carry the same phenotype DRB1*0101,DRB1*0301;DQB1*0501,DQB1*0201;DQA1+ ++*0101,DQA1*0501, which supports the conjecture that immunogenicity of the HBsAg vaccine depends on specific combination of HLA DR and DQ molecules on antigen presenting cells.
Background/Aims Occult hepatitis B infection (OBI) in blood donations is not considered infectious when anti-HBs is present. Methods Four months after transfusion of eight blood components during ...coronary arterial bypass surgery, a 59-year-old patient developed acute hepatitis B. A second 71-year-old patient transfused with a red cell concentrate (RCC) from one of these donations had early HBV infection 7 months post-transfusion. Samples were tested for HBV serological markers and HBV DNA was quantified and sequenced. Results One implicated donation contained anti-HBc, anti-HBs (12 IU/L) and 180 IU/ml of HBV DNA. Previous and subsequent samples contained 3–10 times lower viral load and slightly variable anti-HBs. Two previous donations did not cause HBV infection. Recipients of the FFP and RCC from the index donation were both HBV infected and carried genotype D strains with sequences identical to the donor strain. Conclusions Despite anti-HBs, an OBI carrier transmitted HBV to two immunocompetent transfusion recipients.
Yield of nat screening in Slovenia Stezinar, Snezna Levicnik; Nograsek, Polonca
Zdravniški vestnik (Ljubljana, Slovenia : 1992),
12/2012, Letnik:
81, Številka:
SUPL II
Journal Article
Recenzirano
Odprti dostop
Background: Safe blood supply is the main goal of blood transfusion services. Nucleic Acid Amplification Technologies (NAT) are the methods for direct detection of viral genoms in various biological ...samples. Introduction of NAT blood screening reduces the risk for transfusion transmitted diseases and improves the safety. Methods and Results: In Slovenia NAT screening with PCR (Polymerase Chain Reaction) method for testing pools of samples for hepatitis C virus (HCV) RNA was implemented in 2000. The screening is mandatory for all donations. Until 2007, 590,000 donated units had been screened and there were no HCV RNA-only positive result.In 2007, the testing was expanded to three viruses: HCV, hepatitis B virus (HBV) and human immunodeficiency virus (HIV). The testing method was TMA (Transcription Mediated Amplification) performed on individual donations. In five-year period, 458,000 blood units were screened and two window-period donations positive for HCV were detected (yield 1:524,000). HBV DNA-only was detected in 29 units. All the cases were donors with a resolved HBV infection, in one case the recent one, in others the occult hepatitis B infection (OBI) was confirmed. The yield of NAT testing for HBV is 1:15,600 units. There were no donations with HIV 1 RNA-only result. In all 5 HIV positive units in this period, anti-HIV antibodies were present as well. The yield of HIV NAT-only is thus 0:460,000. Conclusion: The implementation of NAT screening for three viruses has improved the blood safety. In the five-year period, 31 infectious units that were NAT-only positive were eliminated from the stock.
Aims: Hepatitis A virus is transmitted via the faecal-oral route and is the most common cause of acute viral hepatitis in the world. Anti-HAV seroprevalence is higher in less developed regions of the ...world. Transmission of HAV by transfusion is rare. It may occur if the blood is donated in the short time of viremia before the onset of symptoms. The aim of our study was to determine the prevalence of HAV IgG in Slovenian blood donors, and associated with that the susceptibility rate of donor population for HAV infection. Methods: The presence of HAV IgG antibodies was determined in 1000 blood donors from different regions in Slovenia. The testing was performed with CMIA assay on the Architect platform with HAVAb IgG reagents. The results were compared to the results obtained in 1995 on the AxSYM testing systemResults: In 1995 we got 55 % (95 % confidence interval (CI): 52 % to 58 %) prevalence of HAV IgG in blood donors. In 2012, the prevalence was only 28 % (95 % CI: 25 % to 31 %). In older population, the prevalence was higer than in younger population, especially before 45 years of age (53 % (95 % CI: 47 % to 58 %) in individuals aged > 45, and 14 % (95 % CI: 11 % to 17 %) in individuals aged ≤ 45 years; p< 0.0001). Conclusion: More than 80 % of Slovenian blood donors before 45 years of age are susceptible to HAV infection. The incidence of transfusion transmitted HAV infection can be prevented by vaccination of risk groups, careful donor selection procedures and efficient virus inactivation during manufacture of plasma derivatives.
Background: Blood donor screening is the most effective measure to prevent transfusion transmitted infectious agents. In each region, the healthcare authorities provide locally specific suitable ...screening. In Slovenia, screening for various viral markers has been implemented soon after the recognition of the agents and availability of testing techniques. Methods: A twenty-year period of uniform screening in the independent state of Slovenia is presented. Methods and techniques have been changed several times. Currently, we perform serological screening with Enzyme Immuno Assay (EIA). Direct detection of viral genome is performed with the NAT method of Transcription Mediated Amplification (TMA). Results: Results of testing and the frequency of detected infectious markers among donors are presented. During the period, prevalence rates for HBsAg, anti-HCV and anti-Treponema pallidum declined significantly over time. The yield of HIV screening is constant, despite a higher prevalence rate of HIV infection in general population. In the last five years, we detected on average 12 carriers of HBsAg, 5 donors with antiHCV antibodies, 0-2 persons infected with HIV and 10 with syphilis. In twenty years, we screened more than one and a half million of donations and detected more than 1,000 donors with transfusion-transmitted infection. In the year 1991, 1 positive donation was detected in 1,407 tested, compared to significantly decreased number of infections in 2009-1 in 3,550 (p < 0,0001). Conclusions: In the last twenty years, the number of donors with detected viral markers and deferred from blood donations has declined. Nowadays, blood supply is safe also owing to current approaches in blood screening.
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