Hepatitis B--are surgeons putting patients at risk?
The 1993 Department of Health guidelines permit a surgeon who is hepatitis B surface antigen (HBsAg) positive but e-antigen (HBeAg) negative to perform exposure prone procedures, unless demonstrated to have infected patients. However, there is increasing evidence of transmission of hepatitis B to patients from health care workers in this supposedly low infectivity category. The Occupational Physician must decide whether existing guidelines represent an adequate risk assessment and indeed whether this is an acceptable risk for patients. If an NHS Trust continues to follow these guidelines it may be in breach of its duty of care to patients. Yet refusing to allow such carriers to operate without testing for additional serological markers may be unlawful discrimination. Further research is clearly needed as well as an urgent review of the guidelines. (+info)
Third component, HBeAg/3, of hepatitis B e antigen system, identified by three different double-diffusion techniques.
A third component, HB(e)AG/3, of the hepatitis B e antigen system has been detected, and it was consistently detected in three variations of the double-diffusion technique. (+info)
Hepatitis virus infection in haemodialysis patients from Moldavia.
BACKGROUND: Although the epidemiology of hepatitis B (HBV) and C (HCV) now seems well established for Western European countries, in Central and Eastern Europe < 50% of all dialysis centres routinely test for hepatitis C antibodies since testing is not available or is not applied to all patients. This study describes the prevalence, risk factors and clinical significance of HBV and HCV infection for the haemodialysis population of the North Eastern region of Romania, Moldavia. METHODS: The presence of HBV antigens was determined with an ELISA kit (Wellcome, Abbot) and HCV antibodies with the ELISA-3 Ortho-HCV, third generation test. The following individual data were collected: gender, age, duration of dialysis, rural/urban domicile, actual and previous HBV status, actual HCV status, known acute, clinically evident hepatitis episodes in the last 3 years, monthly alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT) levels, complete biochemical hepatic assessment at the time of the study, transfusions for the past 3 years and family history. RESULTS: HBV and HCV prevalences were 17% (stable over the last 3 years) and 75%, respectively; co-infection was seen in 10% of the subjects. Hospitalization (nosocomial infection) for HBV, blood transfusions and duration on dialysis for HCV, emerged as the main risk factors for hepatitis infection. Socio-economic conditions appear to be equally important for HCV infection, since the prevalence was significantly higher among patients from rural, underdeveloped areas than urban areas (80.8 vs 60.3%), and infection was already present in a large proportion of patients (47%) before starting dialysis, without being related to previous disease duration or blood transfusions. HBV and/or HCV was not associated with a worse clinical or biochemical profile at the time of the study. However, infected patients had significantly more previous cytolytic episodes, with higher, transient increases in ALAT and ASAT levels. CONCLUSIONS: HCV infection is endemic among dialysis centres in Moldavia. Apart from previously well-known risk factors for hepatitis infection, our study demonstrates the negative impact of socio-economic underdevelopment. Simple measures such as enforced general asepsia rules, careful disinfection and equipment sterilization, routine testing of patients from economically disadvantaged areas and monthly, serial determination of hepatic enzymes should be the common practice in dialysis centres in Romania. (+info)
Candidate viral diseases for elimination or eradication.
This article discusses the possibilities for elimination or eradication of four viral diseases--measles, hepatitis B, rubella and yellow fever. (+info)
Core promoter mutations and genotypes in relation to viral replication and liver damage in East Asian hepatitis B virus carriers.
Virus load and liver damage, as measured by quantitative polymerase chain reaction and histology activity index, were related to genotype and core promoter mutations in 43 chronic hepatitis B virus (HBV) carriers of East Asian origin. T-1762 mutants were more frequent in genotype C strains and were associated with more inflammation (P=.0036) and fibrosis (P=.0088) of the liver but not with hepatitis B e antigen (HBeAg) status or virus load. Conversely, precore mutations were associated with less liver inflammation (P=. 08), which was linked to HBeAg negativity and lower viral replication. Carriers with genotype C were more often HBeAg positive (P=.03) with precore wild type strains and more-severe liver inflammation (P=.009) than were those with genotype B. These findings suggest that pathogenic differences between genotypes may exist and that the T-1762 mutation may be useful as a marker for progressive liver damage but seem to contradict that down-regulation of HBeAg production is the major effect of this mutation. (+info)
Class II HLA alleles and hepatitis B virus persistence in African Americans.
Persistence of hepatitis B virus (HBV) infection is likely due to the interplay of the virus and host immune response. Given its critical role in antigen presentation, allelic differences in the HLA complex may affect HBV persistence. In a prospectively followed African American cohort, molecular class I and class II HLA typing was done on 31 subjects with persistent HBV infection and 60 controls who cleared the infection. HBV persistence was significantly associated with two class II alleles, DQA1 *0501 (odds ratio [OR], 2.6; P=.05) and DQB1 *0301 (OR, 3.9; P=.01), the two-locus haplotype consisting of these same two alleles (OR, 3; P=. 005) and the three-locus haplotype, DQA1 *0501, DQB1 *0301, and DRB1 *1102 (OR, 10.7; P=.01). In addition, HBV persistence was associated with class II allelic homozygosity. Several class I associations with persistence were also noted but were not statistically significant after correction for multiple comparisons. These results underscore the importance of the class II-mediated immune response in recovery from HBV infection. (+info)
Home delivery of heat-stable vaccines in Indonesia: outreach immunization with a prefilled, single-use injection device.
Extending immunization coverage to underserved populations will require innovative immunization strategies. This study evaluated one such strategy: the use of a prefilled, single-use injection device for outreach immunization by village midwives. The device, UniJect, is designed to prevent refilling or reuse. Stored at ambient temperatures for up to 1 month in midwives' homes, vaccine-filled UniJect devices were immediately available for outreach. Between July 1995 and April 1996, 110 midwives on the Indonesia islands of Lombok and Bali visited the homes of newborn infants to deliver hepatitis B vaccine to the infants and tetanus toxoid to their mothers. Observations and interviews showed that the midwives used the device properly and safely to administer approximately 10,000 sterile injections in home settings. There were no problems with excessive heat exposure during the storage or delivery of vaccine. Injection recipients and midwives expressed a strong preference for the UniJect device over a standard syringe. Use of the prefilled device outside the cold chain simplified the logistics and facilitated the speed and efficiency of home visits, while the single-dose format minimized vaccine wastage. (+info)
Hepadnavirus evolution and molecular strategy of adaptation in a new host.
In order to elucidate the mechanisms of hepadnavirus evolution in vivo and to trace the fate of known quasispecies in a single animal during the acute phase of infection, a woodchuck (Marmota monax) was infected with the hepadnavirus woodchuck hepatitis B virus (WHV). Woodchuck 197 (W197) was injected intravenously with pooled sera collected from a chronic carrier that had been infected originally with a molecular clone of known genome sequence (WHV7). Viral genome variants from both the inoculum and the follow-up sera from W197 were characterized for the presence of quasispecies related to the WHV7 sequence. Interestingly, WHV7-related genomes were predominant 6 weeks post-infection (p.i.), whereas a highly heterogeneous virus population was present in the first viraemic serum (4 weeks p.i.). Using WHV7 as the prototype, the variability of the Pol and PreS/S regions in the first 11 weeks p.i. has been calculated. The sequence population in serum collected 6 weeks p.i. was highly homogeneous, with a mean variability of 0.36% in the region analysed. Mean variability values ranging from 0.82% to 1.61% were found in quasispecies from the other sera. The presence of possible selective pressure was analysed by means of the non-synonymous versus synonymous variation ratio (dn/d5). We found that the dn/d5 values were stable for the S ORF (ranging from 2.6 to 3.0), whereas a wider range was observed for the Pol ORF (from 1.4 to 3.0). Furthermore, from the analysis of the variability of the codon positions for the two overlapping ORFs it was found that, in most cases, non-synonymous mutations at position 1 of the Pol ORF (position 3 of the S ORF) corresponded to synonymous variation in the S (Pol) ORF, indicating independent evolution of the encoded proteins. (+info)