Prevalence of hepatitis G virus and its strain variant, the GB agent, in blood donations and their transmission to recipients.

BACKGROUND: Hepatitis G virus (HGV) and its strain variant, the GB agent (GBV-C) are independent isolates of a recently identified non-A through -E hepatitis virus. Prevalence in United States volunteer blood donors is 1.5 to 1.9 percent, but no data on European blood donors are available. Epidemiologic data suggest a preferred parenteral transmission route. The prevalence of HGV/GBV-C in European blood donors and the efficiency of transmission to transfusion recipients were investigated. STUDY DESIGN AND METHODS: Plasma samples from unpaid volunteer German blood donors were tested for HGV/GBV-C by in-house reverse transcription-polymerase chain reaction. Positive donors were independently retested and interviewed for parenteral transmission risks. Amplification products were sequenced and subjected to phylogenetic analysis. Recipients of reverse transcription-polymerase chain reaction-positive donations were traced and tested for HGV/GBV-C infection. RESULTS: A total of 14 (1.34%) of 1048 donors (alanine aminotransferase < 45 IU/L) were repeatedly positive for HGV/GBV-C with 9 (2.18%) of 413 urban and 5 (0.78%) of 635 rural donors (chi 2-test; p = 0.04). Isolates differed in nucleotide sequence homology over a range of 12.5 to 19.6 percent. All but one positive donor reported parenteral transmission risks. Transmission of HGV/GBV-C was detected in 4 of 9 transfusion recipients. The prevalence of HGV/GBV-C in donors with an alanine aminotransferase level > 45 IU per L was 3 percent (3/100). Two mother/child pairs were identified with highly homologous isolates. CONCLUSION: A significantly greater prevalence of HGV/GBV-C was detected in urban volunteer blood donors than in rural donors. The high prevalence in urban donors (2.18%) suggests specific transmission risks for this group. The less than 50-percent efficiency of HGV/GBV-C transmission via blood components may indicate the presence of defective viruses with reduced infectivity. There is evidence for vertical transmission.

Patterns of mycobacterium avium culture and PCR positivity in immunodeficient HIV-infected patients: progression from localized to systematic disease, German Aids Study Group (GASG/IDKF).

Our aim was to establish the frequency and the longitudinal pattern of MAC culture positivity in late stage HIV-infected patients. Two other aims were to analyse risk factors for progression from localized to systemic disease and the value of PCR diagnosis using blood specimens. A total of 107 patients were recruited to be followed for 32 weeks. Prior MAC treatment and CD4 > 100/microliters were exclusion criteria. A total of 56 patients showed M. avium in at least 1 culture. 10/37 patients with MAC detected by culture first in 'non-sterile' specimens (stool, sputum) and urine progressed to systemic disease as determined by positive blood culture. Risk factors associated with this progression were a high symptom score at baseline, lymphadenopathy, anaemia, and low platelets. PCR was less sensitive than culture in detection of M. avium in blood specimens: Only 7/29 patients with positive blood cultures had a positive PCR at the same time. We conclude that symptomatic patients with advanced HIV-infection have a high frequency of MAC detection. Progression from localized to systemic culture positivity is associated with risk factors. Early 'pre-emptive' therapy is discussed.

[Prevalence of hepatitis G virus genome in blood donors]. / Prävalenz von Hepatitis-G-Virusgenom bei Blutspendern.

The relevance of the GB virus C/hepatitis G virus (GBV-C/HGV) in blood banking results from its high prevalence in blood donors and the fact that it is present at a very high percentage (18%) in polytransfused and hemophiliac patients. Since there is no assay available for serological testing, we developed a sensitive PCR utilizing newly designed NS3 primers to investigate the prevalence in blood donors in Hessia. Testing 1,143 accepted blood donors with alaninaminotransferase (ALT) concentrations < 45 U/l we found 15 (1.3%) positive for GBV-C/HGV RNA. From 507 donors settling in urban Frankfurt areas, 10 (2.0%) were positive. Of those donors settling in rural hessian areas only 5/635 (0.8%) tested positive. By testing 100 excluded donors with ALT values > 45 U/l, 3% turned out to be positive. In 4 out of 9 recipients of GBV-C/HGV-positive blood products we detected the donor viral RNA as proved by sequencing and phylogenetic analysis. The virus was transmitted to 3 recipients by erythrocytes and to 1 recipient by platelets. Testing family members of the GBV-C/HGV-positive blood donors we could not detect any intrafamilial transmission.

Cloning and molecular characterization of the secY genes from Bacillus licheniformis and Staphylococcus carnosus: comparative analysis of nine members of the SecY family.

SecY is a central component of the export machinery that mediates the translocation of secretory proteins across the plasma membrane of Escherichia coli. We have cloned and sequenced the secY genes from Bacillus licheniformis and Staphylococcus carnosus. The deduced amino acid sequences are highly homologous to those of other known SecY polypeptides, all having the potential to form 10 transmembrane segments. Comparative analysis of 9 SecY polypeptides, derived from different bacteria, revealed that 14 amino acid positions (2.7%) are identical in all SecY proteins and 89 (16.9%) show conservative changes. Clusters of conserved amino acid residues were found in 4 of the 10 transmembrane segments and 2 of the 6 cytoplasmic domains. It is suggested that the conserved regions might be involved in the translocation activity of SecY or might be required for the correct interaction of SecY with other components of the secretion apparatus.