Family incidence of type B hepatitis

Family incidence of HBsAg-positive viral hepatitis was confirmed to be high. In 499 families with a type B viral hepatitis patient, type B viral hepatitis morbidity among 1116 contacts amounted to 2.24% within 6 months of the primary patients' hospitalization (being 188.2 times higher than semiannual morbidity of the population of the Czech Socialist Republic, CSR) and the prevalence of HBsAg amounted to 8.96% (being 22.4 times higher than among the population of CSR). On deducting positive findings at first blood samplings, which at least partially eliminated individuals who could themselves have been the source of infection for the first patient in each family, the rate for contact cases equalled 0.70% (58.8 times higher morbidity than among the population) and the rate for HBsAg prevalence equalled 2.50% (6.25 times higher than among the population). Among 917 members of 335 families where a case of HBsAg-negative viral hepatitis occured, 0.32% developed HBsAg-positive viral hepatitis within 6 months (26.8 times higher morbidity than population morbidity) and the HBsAg prevalence was 2.94% (7.35 greater than among the population). On deducting the first positive findings no clinical illness remained and HBsAg prevalence equalle 0.98% (2.45 times higher than among the population). The highest HBsAg prevalence was found among contacts aged 0-5 years (17.09% for the whole period, 3.41% after deducting first positive findings) and 40 years and over (10.82% and 3.39%, respectively). Type B viral hepatitis morbidity was again highest in the age groups of 0-5 years (5.12%) and 40 years and over (2.54%) for the whole period. On deducting first positive findings, the 40+ years group displayed the highest morbidity (1.27%), whereas the 0-5 years group displayed zero morbidity. Disclosure of the mechanisms of nonparenteral or inapparently parenteral transmission specific for family environments would be important for the prospect of introducing adequate measures to limit or prevent the spread of type B viral hepatitis.     

Success of a program of routine prenatal screening for hepatitis B surface antigen: the first 2 years.

Prenatal screening for hepatitis B surface antigen (HBsAg) restricted to women with defined risk factors for chronic hepatitis B virus (HBV) infection fails to identify many carriers. A centralized program of routine HBsAg screening for all pregnant women in Alberta was introduced in 1985. We collected and analysed data for the first 2 years of the program in Edmonton to determine the frequency of risk factors for HBsAg positivity, the proportion of multiparous HBsAg-positive women not identified in previous pregnancies, the efficiency and cost-effectiveness of providing immunoprophylaxis to infants at risk of HBV infection and the degree of success in inducing adequate protection. A total of 149 women (158 pregnancies) were found to be HBsAg positive. Risk factors were readily ascertainable for 85% of the women; the remaining 15% would not have been identified through risk-selective screening. The most common risk factors were Oriental ethnic origin, history of hepatitis, jaundice or multiple transfusions of blood or blood products, and occupational exposure to blood. Although 86% of the multiparous HBsAg-positive women had risk factors, only 7% had been identified in previous pregnancies. The Alberta program appears to be cost-effective. We conclude that only routine prenatal screening will identify all infants at risk of perinatal HBV infection and that a comprehensive public health program involving central laboratories, private physicians and public health staff can be highly effective and efficient in protecting infants against hepatitis B.     

医院工作人员鼻腔葡萄球菌带菌状况年度推移的调查报告

本文报道1989年从202名医院工作人员鼻腔分离葡萄球菌的带菌状况和药敏性检测结果。并将此结果同作者等于1985年对200名同类人员检测的结果相比较,作了年度推移的调查分析发现1989年度的总带菌率(76.6％)比1985年度(84.5％)略有下降,但其中的金黄色葡萄球菌带菌率却从1985年的7.5％上升为10.4％。从1989年和1985两个年度的调查中,均发现临床科室人员金葡菌带菌率高于其它辅助科室人员,说明医务人员带菌率与接触病人成正相关关系。分离菌株对12种抗菌药物的耐药性检测结果显示,1989年分离菌株对其中9种的敏感性下降,并且从耐药谱显示出对5种抗菌药物耐药的多重耐药菌株明显增多。另从金葡菌的耐药情况,也看出1989年的耐药率高于1985年菌株。还在1989年分离的金葡菌中出现25％的耐甲氧西林菌株。     

Hepatitis B markers in southern Altaĭ inhabitants of the village of Mendur-Sokkon (the Republic of Altaĭ). HBsAg subtyping in hepatitis B virus isolates with monoclonal antibodies

Blood samples taken from 231 native inhabitants of the village of Mendur-Sokkon located in the Republic of Altai (South-Western Siberia, Russia) were tested for the presence of virus hepatitis B (HBV) markers. 31 samples (13.4%) were found to contain HBsAg, 111 samples (48.05%) were found to contain total anti-HBc antibodies, 123 samples (53.24%) were found to contain anti-HBs antibodies and 15 blood samples (6.49%), anti-HBc antibodies without anti-HBs antibodies and HBsAg. The age-dependent distribution of the occurrence of HBV markers among the aboriginal population of the South Altal remained unchanged (69.9 +/- 7.9%) for the last 50 years. The vertical and horizontal routes of HBV transmissions were noted. The data obtained in this study are indicative of a highly endemic character of HBV of the territory of Mendur-Sokkon. HBsAg-positive blood samples were taken for HBsAg subtyping with the use of a panel of monoclonal antibodies. Two subtypes of HBsAg were detected: ayw1-2 and ayw3varB with the occurrence of 92.6% and 7.4%, i.e. distributed in the ratio 25/2.     

Seroepidemiology of hepatitis C virus in Beijing, China

To investigate the seroprevalence of hepatitis C virus (HCV) in China we tested sera from healthy individuals without hepatitis and no history of parenteral blood exposure and from patients admitted to a hepatitis hospital in Beijing. Sera were tested for anti-HCV by first-generation enzyme immunoassay; selected positives were tested with two second-generation EIAs, one utilizing recombinant antigens and the other synthetic peptides. We found anti-HCV with the following frequencies: 10 of 164 (6%) individuals with no disease; 2 of 36 (5.5%) patients with acute non-A non-B hepatitis (NANBH); 26 of 39 (67%) patients with post-transfusion NANBH; 10 of 34 (29%) patients with chronic hepatitis negative for hepatitis B surface antigen (HBsAg); 3 of 30 (10%) patients with chronic HBsAg-positive hepatitis; 0 of 19 patients with acute HBsAg-positive hepatitis. Of 24 repeat-positive sera, 19 were positive by both and 4 by one second-generation tests. We conclude that hepatitis C infection is common in China, that it contributes substantially to the incidence of post-transfusion hepatitis, and that HCV plays a significant role in both acute and chronic hepatitis. Further studies are needed to extend these observations and to define the predominant routes of transmission of HCV in China.     

Spread of infection with hepatitis B and C viruses in different population groups of north-western Ukraine

The detection rate of specific markers of hepatitides B and C among the child and adult population, including 487 children in 5 boarding schools, 338 oncological, hematological, urological patients and 206 medical staff members in Rovno and the Rovno region (North-Western Ukraine), was determined. In boarding-school the markers of HB (HBsAg, anti-HBs, summary anti-HBc) were detected 3.5 times more often than among the child population in general (in 28.3 and 8.0% respectively). In children staying in a boarding school for up to 1 year (126 children) these markers were determined in 23% of cases, and in those who stayed there for 3-5 years, in 58.1% of cases. Among the members of the groups where children with HBsAg were found the markers of HB occurred 3.3 more often then among the children in the groups having no HBsAg carriers (45.3 and 13.9% respectively). The detection rates of the markers of HB in children with various kinds of C.N.S. pathology (first of all, with mongolism) and without concomitant diseases were sharply different (they were found, respectively, in 52.9 and 19.6%, including HBsAg in 17.4 and 2.7%). At the same time the detection rate of anti-HCV among boarding-school children (including those with C.N.S. lesions) was no different from that among the child population in general, which was indicative of great differences in the activity of the nonartificial transmission routes HB and HC viruses. Patients with oncological, hematological and urological diseases who had great "parenteral load", as well as medical staff members, formed a high risk group for being infected with both HB and HC viruses.     

Prevalence of hepatitis B markers in Indochinese refugees.

The prevalence of hepatitis B surface antigen (HBsAg) in 14 347 Indochinese refugees was 11.6%; the rate was significantly higher (P less than 0.01) in males (14.0%) than in females (8.8%). Most of the HBsAg-positive refugees were in the age group 20 to 29 years. Antibody to HBsAg was detected in 50.9% of the males and 46.6% of the females, a significant difference (P less than 0.01). Antibody to core antigen alone was found in 2.4% of the males and 2.2% of the females. The cumulative prevalence of one or more hepatitis B markers was significantly higher (P less than 0.001) in the males (67.3%) than in the females (57.5%). The hepatitis B e antigen and its antibody were detected in 54.8% and 39.2% respectively of 1050 HBsAg-positive blood samples. The adw, adr and ayw determinants of HBsAg were found in 23%, 35% and 42% respectively of 74 samples.     

New strategies for blood donor screening for hepatitis B virus: nucleic acid testing versus immunoassay methods

Serologic testing for hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBV core antigen (anti-HBc) has historically been the foundation of blood screening, while HBV nucleic acid testing (NAT) was recently developed to detect HBsAg-negative, anti-HBc-negative blood units donated during early acute infection. Comparison data on seroconversion panels using HBsAg assays of varying sensitivities and pooled- or single-sample NAT, along with viral load estimates corresponding to HBsAg assay detection limits, have provided information on the theoretical benefits of NAT relative to HBsAg. Model-derived estimates have generally been predictive of the yields of DNA-positive, HBsAg-negative window period blood units detected in a number of studies from Europe, Japan, and the US. Studies indicate that the added benefit of pooled-sample NAT is relatively small in areas of low endemicity, with greater yields in areas highly endemic for HBV. Single-sample NAT would offer more significant early window period closure and could prevent a moderate number of residual HBV transmissions not detected by HBsAg assays; however, no fully automated single-sample HBV NAT systems are currently available.Even single-sample HBV NAT may not substitute for anti-HBc screening, as indicated by studies of donors with isolated anti-HBc who have extremely low DNA levels undetectable by standard single-sample NAT and who have been associated with transfusion-transmitted HBV. Moreover, HBsAg testing may still be needed even in the setting of combined anti-HBc and NAT screening. HBsAg-positive units from donors in the chronic stage of infection may contain very low or intermittently detectable DNA levels that single-sample NAT would miss. Although such donors are usually anti-HBc reactive and would be interdicted by anti-HBc screening, some lack anti-HBc. Extensive parallel testing will be needed to determine whether single-sample NAT in combination with anti-HBc might be sufficient to detect all the infectious donors currently interdicted by HBsAg testing. In countries that do not screen for anti-HBc, HBsAg testing would be the only means of detecting donations from chronically infected individuals with low/intermittently detectable DNA, since even single-donor NAT would not identify these potentially infectious blood units. In the future, the current fully automated HBsAg assays may incorporate significant sensitivity improvements, and automated single-sample HBV NAT may become a reality. Each country will need to develop its blood screening strategy based on HBV endemicity, yields of infectious units detected by different serologic/NAT screening methods, and cost effectiveness of test methods in ensuring blood safety.     

Hepatitis B surface antigen and its subtypes in an institution for the mentally retarded.

The prevalence of hepatitis B surface antigen (HBsAg) in 155 patients with Down''s syndrome (DS) and 209 with other types of mental retardation (OMR) at Huronia Regional Centre, Orillia, Ontario was 34.8 and 5.3%, respectively. There was no significant difference in prevalence between males and females in either group of patients. In 75 matched pairs (DS-OMR) the HBsAg prevalence was 45% in DS and 8.3% in OMR males; in females 40% of those with DS were HBsAg-positive, whereas all the OMR residents were negative. The prevalence of HBsAg in both DS and OMR groups was higher in those admitted in early childhood and in those who had resided in the institution for more than 10 years. In all 54 HBsAg-positive DS patients the antigen subtype was ad. Among the 11 HBsAg-positive OMR patients the subtype was ad in 10 cases and ay in 1.     

Genotype and subtype analyses of hepatitis B virus (HBV) and possible co-infection of HBV and hepatitis C virus (HCV) or hepatitis D virus (HDV) in blood donors, patients with chronic liver disease and patients on hemodialysis in Surabaya, Indonesia

Four subtypes (adw, adr, ayw, and ayr ) and eight genotypes (A to H) of the hepatitis B virus (HBV) have been identified. They appear to be associated with particular geographic distribution, ethnicity, and possibly clinical outcomes. In this study, hepatitis B surface antigen (HBsAg) subtyping and HBV genotyping were carried out on sera obtained from HBsAg-positive HBV carriers, including healthy blood donors; patients with acute hepatitis, chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma; and patients on hemodialysis all located in Surabaya, Indonesia. We report here that all HBV isolates tested in Surabaya belonged to genotype B, with more than 90% of them being classified into subtype adw. Our results also revealed that prevalence of hepatitis C virus (HCV) co-infection among HBV carriers in Surabaya was approximately 10% for healthy blood donors and patients with chronic liver disease, and approximately 60% for patients on maintenance hemodialysis. Interestingly, HBsAg titers were lower in HBV carriers with HCV co-infection than in those without HCV co-infection. We also found that prevalence of hepatitis D virus (HDV) co-infection was < 0.5% among HBV carriers in Surabaya.     

Hepatitis B surface antigen (HBsAg) infection in a hemodialysis unit. II. Factors affecting host immune response to HBsAg.

Serum from 86 hemodialysis patients, 105 healthy hospital staff "at risk" and 160 regular hospital staff was screened for hepatitis B surface antigen (HBsAg) and antibody (anti-HBs). The combined prevalence of HBsAg and anti-HBs was higher in the staff of the artificial kidney unit (57.7%) than in the hemodialysis patients (33.7%). The healthy subjects with HBsAg infection responded significantly more often by producing anti-HBs compared with the hemodialysis patients. Twelve of 29 (41.4%) hemodialysis patients with HBsAg infection produced anti-HBs, while 17 (58.6%) remained positive for HBsAg. This differential response could not be attributed to age, sex, time spent undergoing hemodialysis, delayed cutaneous reactivity or response to phytohemagglutinin (PHA) or pokeweed mitogen (PWM). However, a much larger proportion of patients with HBsAg than with anti-HBs had previously received blood transfusions (88.2% v. 33.3%). Our results indicate that development of the chronic HBsAg carrier state or production of anti-HBs in uremic patients may be influenced by the route of immunization or the dose of antigen, or both. Although uremic patients maintain normal in vitro response to PHA and PWM, they may have depressed immunity in vivo because of a decreased total number of T-lymphocytes.     

Q fever: hazard from sheep used in research.

The recent recognition that Q fever is endemic in Ontario and the known occupational risk of Q fever to research personnel working with sheep prompted a study to determine the prevalence of antibodies to the causative organism, Coxiella burnetti, in animals and staff at a Toronto animal research institute. Of 37 sheep 34 (92%) were found to be seropositive--that is, to have a titre of complement-fixing antibody to the phase II antigen of 1:8 or greater. Of 331 staff members tested, 18% were found to be seropositive, compared with 0.6% of a random sample of Toronto blood donors. The highest rate of seropositivity, 68%, was in the 28 animal attendants tested. Seropositivity was associated with working with sheep or fetal lamb tissue (p less than 0.0001) and with visiting the animal facility (p less than 0.001). Of the 59 seropositive staff members 63% had had no direct contact with sheep. There were 12 clinically apparent cases of Q fever, 2 of which required admission to hospital. Q fever remains a serious occupational hazard to staff working in research laboratories using sheep, even to those with indirect exposure to infected animals.     

Seroepidemiologic study of adult T-cell leukemia virus (ATLV) and hepatitis B virus infection in Okinawa, Japan

A total of 2,283 serum samples were collected from healthy subjects in three islands of the Yaeyama district of Okinawa, Japan. These sera were tested for the presence of hepatitis B surface antigen (HBsAg), for antibody to hepatitis B core antigen (anti-HBc), and for antibody to adult T-cell leukemia-associated antigen (anti-ATLA). Correlation between hepatitis B virus infection and adult T-cell leukemia virus (ATLV) infection was determined by using the prevalence rates for three virus markers. Overall prevalence of HBsAg, anti-HBc and anti-ATLA was 6.5%, 57.4%, and 17.9%, respectively. Age-specific prevalence of anti-HBc and anti-ATLA increased with age, but that of HBsAg did not. Sex-specific prevalence of HBsAg was significantly higher in males than in females, but that of anti-ATLA was significantly higher in females than in males. Statistical analysis revealed that prevalence of anti-ATLA was significantly higher in HBsAg-positive persons and HBsAg-negative/anti-HBc-positive persons than in those negative for HBsAg and anti-HBc. These data suggest that hepatitis B virus-infected persons have a significantly higher chance of adult T-cell leukemia virus infection than those without hepatitis B virus infection in the area studied.     

Sensitivity and specificity of Czechoslovak ELISA HBsAg Sevac tests: comparison with other third-generation tests and counter-immunoelectrophoresis

Two variants of sandwich-type ELISA (Enzyme Linked Immunosorbent Assay) kits for HBsAg detection (Sevatest ELISA HBsAg Macro I and Sevatest ELISA HBsAg Micro I) in human sera and plasmas were developed. As the solid phase, the ELISA Macro kit and ELISA Micro kit make use of polystyrene microtubes, and polystyrene microtitration plates, respectively, of Czechoslovak production (Koh-i-noor, Dalecín). Capture anti HBs antibody for adsorption to solid phase and rabbit anti HBs antibody for labelling with horse-radish peroxidase were prepared for both tests. The sensitivity of both ELISA kits for HBsAg, equal to approx. 2 ng/ml, was determined by titrating six selected HBsAg-positive sera and the WHO Agk 76 panel of HBsAg-positive sera and the results were compared with those obtained by ELISA, RIA (Radioimmunoassay) and RPHA (Reverse passive hemagglutination) kits of different producers and by counter-immunoelectrophoresis (CIEP). The sensitivity of the new ELISA kits was comparable to that of other producers' ELISA kits, higher than that of RPHA kits and only a little lower than that of RIA kits. A set of sera of patients hospitalised with different diagnoses was tested for HBsAg. The detection rate by ELISA Macro kit 2.8 and 1.5 times higher than by CIEP and RPHA (Raphadex B), respectively, and 1.1 time lower than by RIA (Austria II).     

慢性乙型肝炎病毒感染自然史中HBsAg和HBsAb共存血清学模式分析

目的分析慢性乙肝病毒感染者HBsAg和HBsAb共存模式中血清学指标、HBV-DNA和肝酶等指标与自然病程的关系,探讨其临床意义。方法回顾性分析2016年重庆医科大学附属第一医院HBsAg和HBsAb双阳性患者的血清学指标、HBV-DNA和ALT、GGT检测结果,并对其感染的自然病程进行分析。结果 2016年该院HBsAg和HBsAb双阳性患者共520例,占全部HBV感染者的2.80%,占总送检标本数的0.42%。可分期的184例双阳性患者中,免疫耐受期47例(25.54%),免疫清除期17例(9.24%),低复制期108例(58.70%),再活动期12例(6.52%),HBsAg、HBsAg/HBsAb比值、HBV-DNA、ALT和GGT水平差异均有统计学意义(P<0.05),低复制期患者HBsAg/HBsAb比值均低于其他患者(P<0.05)。不同分期患者HBsAb、年龄和性别比较差异无统计学意义(P>0.05),且HBsAb水平均较低。284例资料完整HBsAg和HBsAb共存病例中HBV-DNA阳性136例,占47.89%。HBsAg浓度与HBV-DNA载量成正相关(r=0.295,P<0.05),HBsAb浓度与HBV-DNA载量之间没有显著相关性(r=0.04,P>0.05)。结论 HBsAg和HBsAb共存患者并不少见,与性别无关,可发生在各个年龄阶段,以低复制期患者为最多。HBsAg和HBsAb共存患者中HBsAb多以低浓度形式存在,且浓度与自然病程无关。HBsAb的出现并非代表患者体内病毒复制停止,在诊断及治疗HBsAg和HBsAb共存模式的乙肝病毒感染者时仍需结合HBV-DNA载量来判断感染状态。     

Retrospective review of the prevalence of hepatitis B virus in several population groups

Nine different groups of individuals studied from 1969 to 1985 were tested for Hepatitis B Virus (HBV) markers. In 8 groups only HBsAg in serum was tested, in another group: tissular HBsAg, and in two of those groups: serum HBsAg, anti-HBs and anti-HBc. Mean HBsAg prevalence in groups similar to general population was 0.64%; 5% in cirrhotics; HBV prevalence in haemophiliacs was 18.87% by testing serum for HBsAg and anti-HBs; serum HBsAg prevalence in Viral Chronic Active Hepatitis was 43.24%; and Hepatocellular Cancer (HCC) group had a prevalence for HBV of 13.04% when only tissular HBsAg was tested, and 54.29% when serum HBsAg, anti-HBs and anti-HBc were tested in all patients. Costa Rica has a low HBV markers prevalence only similar to what is found in industrial developed countries.     

Genetic variability of hepatitis B virus isolates among population of Shuryskarsky area of Yamal-Nenets autonomous region

The purpose of this work was to determine occurrence of serological markers of hepatites B and to describe subtypes of a superficial antigen and genotypes of hepatitis B virus (HBV) isolates among indigenous population of Yamal-Nenets Autonomous Region (YNAR), Russia. METHODS: We investigated 657 serum samples from inhabitants of Shuryskarsky area of YNAR. ELISA method was used to define the hepatitis B markers: HBsAg, anti-HBs (total) and anti-HBc (IgG and IgM). The HBsAg-positive samples were PCR-tested for the presence of HBV DNA. Genotyping of isolates was by sequencing of the Pre-Sl/Pre-82/S region of HBV genome and phylogenetic analysis. Definition of HBsAg subtypes was executed by two methods: ELISA with subtype-specific monoclonal antibodies and S-gene nucleotide sequence analysis. RESULTS: The following occurrence of hepatitis B markers was observed: HBsAg - 3.2%, anti-HBs (total) - 36.2%, anti-HBc IgG - 30.3%, anti-HBc IgM - 1.6%. Frequency of carrying even one of the markers in the observed population was 47.5%. HBV DNA was found in 17 HBsAg-positive samples. Pre-SI, Pre-S2 and S regions sequences were determined for all HBV DNA-positive samples. The phylogenetic analysis showed an accessory of all investigated HBV isolates to genotype D. HBsAg subtypes distribution appeared the following: ayw2 - 23.5%, ayw3 - 70.6%, adw2 - 5.9%. Results of definition of the subtype ELISA method and by the analysis of S gene nucleotide sequences have coincided in 10/11 (90.1%) cases. CONCLUSIONS: The indigenous population of Shuryskarsky area of YNAR belongs to groups with average HBV carrying. Absolute domination of genotype D (subtypes ayw2, ayw3 and adw2) was revealed. High percentage of concurrence of HBsAg subtypes detected by the ELISA method and method of the analysis of S gene primary structure (90%) was observed. Sequencing of HBV S-gene is preferable to define HBsAg subtypes.     

Hepatitis B in a hospital for the mentally subnormal in southern England.

The prevalence of hepatitis B viral (HBV) infection was assessed in 340 patients and 268 staff in a hospital for the mentally subnormal in Wessex. Hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen, antibody to HBsAg, e antigen (eAg), and antibody to eAg were used as markers of such infection. Forty patients and 10 staff had evidence of recent or current infection, while 149 patients and 50 staff had evidence of past infection. HBV markers were more common in mongols, epileptics, patients with cerebral palsy, and those of lower mental grades and reached a peak after 5-15 years of hospitalisation. eAg was detected in 12 out of 26 patients with HBsAg but in none of the four staff with HBsAg. Abnormal liver function values were found in 24 (60%) of the patients with recent or current HBV infection but in only 30 (19%) of those without HBV markers. Among the staff the prevalence of HBV markers correlated with the duration of employment and degree of contact with patients. Of those with recent or current infection, 4 (40%) had abnormal liver function values compared with 25 (12%) of those without HBV markers. Despite the high prevalence of markers clinically overt hepatitis B was rare.     

Hepatitis B virus infection profile in hemodialysis patients in Central Brazil: prevalence, risk factors, and genotypes

Hemodialysis patients are at high risk for hepatitis B virus (HBV) infection. A survey was conducted in the hemodialysis population of the state of Goiás, Central Brazil, aiming to assess the prevalence of HBV infection, to analyse associated risk factors, and also to investigate HBV genotypes distribution. A total of 1095 patients were interviewed in 15 dialysis units. Serum samples were screened for HBV serological markers by enzyme-linked immunosorbent assay. Hepatitis B surface antigen (HBsAg) positive samples were tested for HBV DNA by polymerase chain reaction and genotyped by restriction fragment length polymorphism. Global HBV infection prevalence was 29.8% (95% CI: 27.1-32.5). Multivariate analysis of risk factors showed that male gender, length of time on hemodialysis, and blood transfusion before 1993 were associated with HBV positivity. HBV DNA was detected in 65.4% (17/26) of the HBsAg-positive samples. Thirteen of 17 HBV DNA positive samples were genotyped. Genotype D (61.5%) was predominant, followed by A (30.8%), while genotype F was detected in only one (7.7%) sample.     

Screening of Danish blood donors for hepatitis B surface antigen using a third generation technique.

The profit to be gained by testing Danish blood donors for hepatitis B surface antigen (HBsAg) with a third generation technique instead of the currently used immunoelectrophoresis was investigated by additional screening of 48 750 blood units by radioimmunoassay three weeks after donation. Twenty nine units were positive for HBsAg on radioimmunoassay (0.059%). Only six of these were found by immunoelectrophoresis (0.012%). Most of the 23 donors positive on radioimmunoassay and negative on immunoelectrophoresis were healthy carriers of HBsAg (20) or had asymptomatic chronic liver disease (two). One donor had acute hepatitis B. Fifteen of the 23 blood units were transfused. The 15 recipients were monitored biochemically and serologically for up to nine months. One recipient developed fulminant hepatitis B, three developed acute hepatitis B, and one became a healthy carrier of HBsAg. All these patients had received blood from healthy carriers of HBsAg. Two recipients were immunised against HBsAg, and in one patient no seroconversion was observed. The remaining recipients died soon after transfusion or were protected by antibodies to HBsAg that had been present before the transfusion. Testing of Danish blood donors using a third generation technique identified a substantial number of donors positive for HBsAg overlooked by immunoelectrophoresis. Most of these donors were healthy carriers of HBsAg. Blood taken from such carriers is highly infectious when transfused, probably because of the large amount of material transmitted.