Hepatitis-associated antigen (HAA) in acute viral hepatitis. Serological and clinical studies

Subtypes of Hepatitis B Antigen in Blood Donors and Post-transfusion Hepatitis: Clinical and Epidemiological Aspects

Subtyping of hepatitis B antigen (HBA) in blood donors revealed subtype ad in 56% while patients with icteric post-transfusion hepatitis from the same centre showed subtype ay in the majority of the cases (75%). Donors with subtype ad in serum were mostly asymptomatic long-term carriers of the antigen with normal liver function (83%), while 70% of donors with subtype ay in serum had signs of acute or chronic liver disease. Healthy long-term carriers of HBA seem to present little risk of transmitting hepatitis irrespective of subtype. It is, however, possible that these differences in blood donors with subtype ad and patients with post-transfusion hepatitis with subtype ay might reflect epidemiological circumstances rather than biological differences in the two viral strains.

Epidemiological patterns of hepatitis B virus (HBV) in highly endemic areas

This paper uses meta-analysis of published data and a deterministic mathematical model of hepatitis B virus (HBV) transmission to describe the patterns of HBV infection in high endemicity areas. We describe the association between the prevalence of carriers and a simple measure of the rate of infection, the age at which half the population have been infected (A50), and assess the contribution of horizontal and perinatal transmission to this association. We found that the two main hyper-endemic areas of sub-Saharan Africa and east Asia have similar prevalences of carriers and values of A50, and that there is a negative nonlinear relationship between A50 and the prevalence of carriers in high endemicity areas (Spearman's Rank, P = 0.0086). We quantified the risk of perinatal transmission and the age-dependent of infection to allow a comparison between the main hyper-endemic areas. East Asia was found to have higher prevalences of HBeAg positive mothers and a greater risk of perinatal transmission from HBeAg positive mothers than sub-Saharan Africa, though the differences were not statistically significant. However, the two areas have similar magnitudes and age-dependent rates of horizontal transmission. Results of a simple compartmental model suggest that similar rates of horizontal transmission are sufficient to generate the similar patterns between A50 and the prevalences of carriers. Interrupting horizontal transmission by mass immunization is expected to have a significant, nonlinear impact on the rate of acquisition of new carriers.

Acute non-A, non-B hepatitis in Norway. Clinical, epidemiological, and immunological characteristics in comparsion with hepatitis A

Serological analysis by radioimunoassay of sera from 297 patients hospitalized with acute non-toxic hepatitis was used for classification according to virus etiology. Radioimmunoassays included tests for hepatitis B surface antigen (HBsAg), antibody to HBsAg (anti-HBs), antibody to hepatitis A virus (anti-HAV), anti-HAV of IgM class, and antibody against cytomegalovirus (GMV) and Epstein-Barr virus. One patient with a significant rise in anti-CMV antibodies was classified as having CMV hepatitis. Among the 296 remaining patients serological markers indicated hepatitis A in 51 cases (17.2%) and hepatitis B in 208 cases (70.3%). The remaining 37 patients (12.5%) fulfilled criteria for acute non-A, non-B hepatitis. This type of hepatitis had symptoms and signs indistinguishable from those of hepatitis A, except for a slight tendency to milder disease on admission. A considerable proportion of patients with non-A, non-B hepatitis had a history of drug abuse (43.2%) and of recently traveling to endemic hepatitis areas (29.7%). In the remaining 27.1% no particular background was revealed. No case of post-transfusion hepatitis was seen. During the last 6 months of the study a striking change in epidemiology concerning hepatitis A was seen, apparently caused by a steep increase in the incidence of this type of hepatitis among drug addicts. No significant difference in biochemical liver tests was seen in non-a, non-B hepatitis or hepatitis A. In contrast, a marked and statistically significant difference in serum concentrations of IgM was found, with higher values (mean, 7.5 g/1; range, 3.2-13.9 g/1) in hepatitis A than in non-a, non-B hepatitis (mean, 3.3 g/1; range, 0.9-9.4 g/1). This difference may have diagnostic value.

Clinical, epidemiological and prognostic aspects of hepatitis "non-A, non-B"--a comparison with hepatitis A and B

Sera of 480 hospitalized hepatitis patients were tested for hepatitis B surface antigen (HBsAg), antibody to HBsAg (anti-HBs) and to hepatitis B core antigen (anti-HBc), antibody to hepatitis A virus (anti-HAV) and anti-HAV of IgM-class. Serological markers indicating hepatitis A infection were found in 107 (22.3%) and markers indicating hepatitis B in 297 patients (61.9%), while 63 patients (13.1%) were classified as hepatitis type "non-A, non-B". The latter group mainly comprised drug addicts (50.8%), cases of post-transfusion hepatitis (11.1%) and patients without obvious hepatitis exposure (28.6%). In spite of these epidemiological similarities to hepatitis B, the maximum levels of serum alanine aminotransferase and bilirubin were comparable to those in patients with hepatitis A and significantly lower than in hepatitis B infection. Chronic hepatitis developed in 7.1% of the "non-A, non-B" patients, a figure close to that reported for hepatitis B.

Hepatitis B virus infection in children. A sero-epidemiological study in three endemic areas

The occurrence of hepatitis B surface antigen (HBsAg) and anti-HBs was studied in 254 children aged 0 to 19 years from three areas in Greenland and West Africa, endemic for hepatitis B virus (HBV) infection. Age specific prevalence rates for HBsAg increased in all areas until the age of 10 years while the prevalence of anti-HBs showed a continuous rise and reached maximum level of 44 to 80% in the age group 15 to 19 years. The study results indicate that in these areas infection with HBV occurs throughout childhood, and that HBsAg carriership is derived mainly from infection in the first decade of life, but not only neonatal infection, Such data are necessary for all areas in which attempts to control HBV infection are being made.

Coenzyme-B12 therapy in acute viral hepatitis

Extra vitamins are needed to repair tissue damage and compensate for diminished hepatic storage during viral hepatitis. Coenzyme-B12 has recently been synthesized and ought to have a favourable effect on the damaged liver cell as has previously been reported for cyanocobalamin, since it is better absorbed by oral administration and to a greater extent accumulated in the liver. Two groups of patients from the same hepatitis A epidemic were treated with either coenzyme-B12 or cyanocobalamin. A more rapid return of serum aminotransferase (S-ALAT) levels to normal was observed in the group treated with coenzyme-B12.

The long-term outcome of hepatitis B

Among 466 hospitalized patients with serologically verified acute hepatitis B, 440 individuals (94.4%) could be followed up until normalization of liver function had occured, or for at least one year. In 90.2% of the patients followed-up liver function including galactose tolerance) returned to normal within four months after onset of illness. Chronic persistent hepatitis B surface antigen (HB Ag) for at least one year in 14 patients (50%). Liver biopsy was performed in consistent with CPH in all cases. Histological signs of chronic aggressive hepatitis developed in 15 patients (3.4%) and persistence of HB Ag was observed in 11 of these patients (73%). No histological follow-up was performed in patients with normal liver function within four months after onset of illness. Cprticosteroid treatment in 56 patients with prolonged symptoms did not seem to predispose to persistence of HbsaG in the serum.

New light on the transmissibility of viral hepatitis in dental practice and its control

Evidence of an increase in the nonparenteral spread of viral hepatitis is of much concern in dentistry and supports the need for sterilization of all instruments used in intraoral treatments. Methods for the rapid sterilization of all dental handpieces and air-water syringes are still inadequate for routine clinical use. It may be possible to improve surface disinfection of these items by more thorough, repeated cleansing with common disinfectants and by the use of stronger germicidal agents such as aldehydes. However, for handpieces and some other equipment, effective sterilization methods must be developed or the instruments must be modified so they can be safely and rapidly sterilized. Surface disinfectants that will destroy hepatitis viruses are needed for disinfection of the dental unit. The use of gloves is also an important consideration for the protection of both the dentist and his patient. The high attack rate of hepatitis among surgeons, as well as patient protection, make the wearing of gloves during surgery imperative. Evidence that aerosolborne viruses would be removed by filtered laminar air flow or by face masks is not available, but use of these devices reduces exposure of personnel to aerosols in general and appears to be highly desirable. Sterilization of all possible instruments is advocated for use in all institutions and dental offices. Careful monitoring of the effectiveness of sterilization also is advocated. These concepts and new information on which they are based should be incorporated into dental curriculums and continuing education courses for all dentists and auxiliary personnel.

Acute viral hepatitis: a comparative study of clinical, biochemical, morphological and immunological features in patients with and without Australia Antigen

500 consecutive patients with acute viral hepatitis verified by biopsy were divided into groups of 202 patients with detectable Australia (Au) antigen and 298 patients without antigenaemia at the time of admission to hospital. Comparison was made of the initially recorded clinical, biochemical, histological and serological variables in the two groups. Judged by both histological and biochemical criteria, the acute disease was more severe in the 202 patients with Au antigen than in the 298 patients without Au antigen. Evidence is presented that this difference is possibly due more to qualitative aetiological differences between the two groups than to the duration of antigenaemia or the time of hospitalization. Thus, the demonstration of Au antigenaemia provides not only epidemiological but also relevant clinical information.

Hepatitis B antigen and prevention of post-transfusion hepatitis B

Screening for hepatitis B antigen (HB-sAg) in the serum of blood donors and exclusion of antigen-positive blood units have reduced the frequency of post-transfusion hepatitis but several cases of hepatitis B still occur in association with transfusions. One explanation for this is probably that HB-sAg is not an indicator of infectivity. Thus healthy carriers of the antigen seem to have low infectivity while carriers with chronic liver disease as well as donors incubating hepatitis B probably present a great risk.

Liver morphology in acute viral hepatitis related to the hepatitis B antigen

The liver histology in infectious hepatitis or hepatitis A (HA) and serum hepatitis or hepatitis B (HB) is generally described as identical. However, the clinical separation of the two types has been a problem. Today a serological reaction based on the well documented association between hepatitis antigen and HB is of great assistance in the differential diagnosis. The present study of 165 hepatitis cases separated into hepatitis A and B by this test method indicates quantitative differences in the liver histology of the two types. Thus HB was associated with more prominent parenchymal cell damage and Kupffer cell reaction, while intrahepatic cholestasis was found in a significantly higher frequency in cases presumed to represent HA. The presence of intrahepatic cholestasis was associated with higher levels of serum bilirubin but otherwise no correlation was found between liver morphology and biochemical liver tests. The patients included a group of young intravenous amphetamine addicts with HB. No differences of importance were found histologically in addicts and other patients with hepatitis B.