Hepatitis B: global importance and need for control

The role of interferon in the treatment of viral hepatitis

Chronic viral hepatitis, frequently an asymptomatic disease, can persist for decades. Despite the lack of symptoms, prolonged infection can lead to the complications of cirrhosis, liver failure and hepatocellular carcinoma. The goal of therapy is to reduce the risk of developing these complications and to eradicate the infectious pool. Patients with ongoing viral replication appear to be at greatest risk for developing complications. These patients have been targeted for treatment. Numerous randomized studies of interferon treatment of chronic hepatitis B and C have been published in the last 8 years. The experience from these studies and more recent developments will be reviewed.

Modelling the impact of mass vaccination against hepatitis B. I. Model formulation and parameter estimation

A new model of the transmission dynamics of hepatitis B virus in countries with high transmission rates is presented. The model is age and sex stratified, and includes details of host demography. Details of hepatitis B natural history, such as the existence of infectious and non-infectious carriers, are included. The biological assumptions of the model are discussed in full and related to the model's equations. Hepatitis B epidemiological data is reviewed with special emphasis on the estimation of model parameter values from field data. A full set of model parameter values are derived. Possible uses of the model in the assessment of strategies of mass vaccination are discussed.

Simultaneous administration of hepatitis B vaccine with other E.P.I. vaccines

Development of recombinant DNA vaccine against hepatitis B grown on cultured yeast cell has made it possible to mount a world-wide effort to control and eradicate Hepatitis B infection. However, the currently recommended schedules (0, 1 & 2 months, and 0-1 and 6 months) do not coincide with the scheduled visits for other E.P.I. vaccines, and necessitate additional visits for Hepatitis B vaccination. This study was therefore carried out to find out if adequate seroconversion occurs to Hepatitis B vaccine when given with other EPI vaccines or not? Thirty nine infants born to Australia antigen positive mothers from among 850 screened pregnant mothers were recruited to receive Hepatitis B vaccine (Engerix B-10 micro gram each) at 0, 6 and 14 wks (group A) or at 0, 1 and 2 months (group B). Thirty-one infants were recruited in group A and 8 in group B. The cord blood was collected and the first dose of vaccine was given within 48 hours of birth. Simultaneous B.C.G. was given at the left deltoid. Other E.P.I. vaccines were given qt 6, 10 and 14 wks in group A and at 2, 3 and 4 months in group B. Repeat blood samples were collected prior to giving each dose of Hepatitis B vaccine, and 4 weeks after the last dose. All blood samples were assayed for HBsAg and HBsAb at the National Institute Of Communicable Diseases, utilizing standard ELISA kits. The seroconversion rates following one, two and three doses of Hepatitis B vaccine were 3.33%, 55.5%, 96.15% and 0%, 62.5% and 100% in group A and B respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Management of chronic hepatitis in special populations

Over the last several years, much progress has been made in the treatment of adult patients with chronic viral hepatitis and compensated liver disease in the absence of significant other illnesses. However, the treatment of chronic viral hepatitis in other patient populations is still experimental. These groups include children, patients immunocompromised by human immunodeficiency virus infection or immunosuppression following organ transplantation, those with end-stage renal disease, and patients with extrahepatic manifestations of hepatitis viral infection. Data on the treatment of chronic hepatitis in these special populations are reviewed.

Hepatitis B carriers in Sweden--effects of immigration

The number of hepatitis B carriers in Gothenburg, the second largest city in Sweden, has gradually increased between 1980 and 1990. Altogether 525 chronic carriers (35% females) were found, corresponding to a prevalence of 0.11%. 401 (76%) were immigrants from high or medium prevalence regions, mainly the Middle East and Southeast Asia. 102 were native Swedes (19%). In 1988-90 the immigrants constituted 85% (154/182) of all new cases. 93% (245/264) of the carriers born in 1960-89 were immigrants, whereof 53% (130/245) were HBeAg positive. The increasing number of hepatitis B carriers in Sweden places demands on the public health service to undertake measures to prevent new cases of hepatitis B, as well as to discover and treat chronic liver disease induced by hepatitis B virus.

Analysis of a cellular model to account for the natural history of infection by the hepatitis B virus and its role in the development of primary hepatocellular carcinoma

Infection with the hepatitis B virus (HBV) can have many different outcomes. Transient infection may result in acute hepatitis or may remain subclinical. Persistent infection may also be subclinical, or may involve chronic active hepatitis, and can finally lead to the development of primary hepatocellular carcinoma. A mathematical model is given to account for the many different outcomes of HBV pathogenesis. The model is based on the assumption that the liver contains two cell populations with differing abilities to support active HBV replication and/or viral integration into the genome. The model helps account for the relationship of the different clinical courses of HBV infection to the age when the disease is acquired, together with the state of the immune system of the patient.

Gianotti-Crosti syndrome: a retrospective analysis of 308 cases

BACKGROUND

There is no agreement as to whether papular acrodermatitis of childhood caused by hepatitis B virus can be differentiated from other papulovesicular acrolocated syndromes.

OBJECTIVE

We attempted to establish whether such differentiation is possible comparing histories, signs, and symptoms of all patients who have been previously diagnosed as having papular acrodermatitis of childhood or papulovesicular acrolocated syndromes.

METHODS

Files of 308 patients hospitalized in the past three decades were studied. Photographs were examined by a panel of experts to determine whether it was possible to distinguish between papular acrodermatitis of childhood and papulovesicular acrolocated syndromes solely on the basis of cutaneous signs.

RESULTS

The retrospective analysis confirmed a significant overlapping of the two types of the disease. The blind survey of photographs of the patients revealed that a distinction between the forms was not clinically possible.

CONCLUSION

Acrodermatitis is a self-limiting cutaneous response to different viruses; clinical differences are probably due to individual characteristics of each patient rather than the causative virus.

Contribution to hepatitis B prevention

Hepatitis B is widely recognized as an important public health problem. The only effective way to control hepatitis B is by vaccination. First generation plasma-derived hepatitis B vaccines have limitations. Advances in recombinant DNA technology have led to the development of yeast-derived recombinant hepatitis B vaccine which is now used extensively in the developed world. This article reviews the development of this new generation vaccine and the efforts to facilitate universal vaccination programmes particularly in the developing world. The issue of the cost of new generation vaccines, in relation to the major investment required for research and development and also the quality of the final product, is discussed.

Persistence of antibody to hepatitis B surface antigen after low-dose, intradermal hepatitis B immunization and response to a booster dose

To determine the duration of antibody after low-dose, intradermal (i.d.), plasma-derived hepatitis B vaccination and the response to a booster dose, we studied two classes of medical students who were immunized with 2 micrograms doses i.d. In one class, 73/88 (85%) who had been immunized by skilled personnel at 0, 1 and 6 months, had protective concentrations (greater than or equal to 10 mIU ml-1) of anti-HBs at 20 months after the first dose. Twelve (92%) out of 13 students who received only two doses at 0 and 1 months also had protective concentrations at month 20. At month 27, 11/16 (69%) with antibody less than or equal to 10 mIU ml-1 responded to a fourth dose of 2 micrograms i.d. with protective concentrations of anti-HBs. In the second class, after three doses of vaccine at 0, 1, and 6 months, protective concentrations of anti-HBs were present in 90/93 (97%) at 14 months and in 71/80 (89%) at 25 months. In those who received only two doses, protective concentrations were found in 24/31 (74%) at 14 months and 9/16 (56%) at 25 months. After a booster dose of 2 micrograms i.d. at month 25, anti-HBs concentrations rose from a geometric mean of 78 to 1198 mIU ml-1 in 60 subjects previously immunized with three doses and from 18 to 1054 mIU ml-1 in 16 students previously immunized with only two doses. Overall, 73/76 (96%) of students in the second group had protective concentrations of antibody after the booster dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Therapeutic advances in the prevention of hepatitis B: yeast-derived recombinant hepatitis B vaccines

Viral hepatitis is second to gonorrhea as the most commonly reported infectious disease in the US. Hepatitis B accounts for the majority of viral hepatitis cases. Fortunately, the disease is self-limiting and frequently resolves completely with minimal complications; however, a significant number of individuals may experience long-term sequelae. Research utilizing genetic engineering has led to the development of yeast-derived recombinant DNA (YDR) hepatitis vaccines--a significant advancement in the control and prevention of hepatitis B. The recombinant process allows production of unlimited quantities of vaccine at considerably lower cost and without the potential threat of blood-borne illness. Clinical trials in various high-risk populations have demonstrated the effectiveness and safety of YDR vaccines. However, questions regarding optimal regimen and the need for periodic revaccination remain unanswered. Persons at risk should be adequately vaccinated against hepatitis B.