Non-A, non-B post-transfusion hepatitis

Antiviral Effect of Interferon Therapy for Patients with Chronic Hepatitis C

Thirty-two patients with chronic hepatitis who were positive for hepatitis C virus (HCV) RNA by polymerase chain reaction and had antibody to HCV (anti-HCV), were enrolled in this study. Twenty of them were also positive for antibody to the GOR epitope (anti-GOR). Sixteen of the enrolled patients were treated with human lymphoblastoid interferon for six months. Treatment was initiated with 3 million units of interferon daily for 2 weeks, followed by 3 million units three times a week for 6 weeks and 1.5 million units three times a week for 16 weeks. The efficacy of therapy was assessed by comparison with the results in 16 untreated patients. Aminotransferase values, titre of anti-HCV and anti-GOR antibodies showed significant decreases throughout the therapy compared with baseline levels and the untreated patients. After a 3 month follow-up, nine treated patients (56.3%) had normal aminotransferase activities and six of them eliminated HCV RNA from their sera (37.5%). Three of these six patients became negative for both anti-HCV and anti-GOR antibodies (18.8%). None of the untreated control patients had normal aminotransferase activities or became negative for HCV markers. The present study suggests that human lymphoblastoid interferon can control the disease activity and eliminate hepatitis C virus from patients with chronic hepatitis C.

Epidemiology of Hepatitis C Virus: A Battle on New Frontiers

The hepatitis C virus (HCV) is a leading cause of liver-related morbidity and mortality in the United States and other parts of the world. The epidemiology of the disease is highly variable between and within countries, and strategies to deal with HCV identification and treatment must be tailored to the geographic location and the political and economic environment of the region. Although great strides have been made in improving HCV transmission risk in blood supply products, new challenges related to changing patterns of disease incidence continue to require fresh evaluation and new approaches to disease prevention.

Current testing strategies for hepatitis C virus infection in blood donors and the way forward

Screening tests for blood donations are based upon sensitivity, cost-effectiveness and their suitability for high-throughput testing. Enzyme immunoassay (EIAs) for hepatitis C virus (HCV) antibodies were the initial screening tests introduced. The ”first generation“ antibody EIAs detected seroconversion after unduly long infectious window period. Improved HCV antibody assays still had an infectious window period around 66 d. HCV core antigen EIAs shortened the window period considerably, but high costs did not lead to widespread acceptance. A fourth-generation HCV antigen and antibody assay (combination EIA) is more convenient as two infectious markers of HCV are detected in the same assay. Molecular testing for HCV-RNA utilizing nucleic acid amplification technology (NAT) is the most sensitive assay and shortens the window period to only 4 d. Implementation of NAT in many developed countries around the world has resulted in dramatic reductions in transfusion transmissible HCV and relative risk is now < 1 per million donations. However, HCV serology still continues to be retained as some donations are serology positive but NAT negative. In resource constrained countries HCV screening is highly variable, depending upon infrastructure, trained manpower and financial resource. Rapid tests which do not require instrumentation and are simple to perform are used in many small and remotely located blood centres. The sensitivity as compared to EIAs is less and wherever feasible HCV antibody EIAs are most frequently used screening assays. Efforts have been made to implement combined antigen-antibody assays and even NAT in some of these countries.

Viral infections and human cancers: the legacy of Denis Burkitt

Denis Parsons Burkitt was born in 1911, and in the late 1950s, described the disease that has come to be known as Burkitt lymphoma based on cases he observed in Uganda. Subsequently, Burkitt lymphoma was recognized as the first human tumour associated with an infectious agent when Epstein-Barr virus was isolated from samples supplied by Burkitt. It is now recognized that over one-quarter of cancers worldwide are tied to infections. Notably, liver cancer is linked to hepatitis B virus and hepatitis C virus infections, and cervical cancer to infections involving the human papilloma viruses. In addition, immunocompromise arising from infection with the human immunodeficiency virus allows tumours (e.g., Kaposi sarcoma) caused by other viruses to arise. More than 50 years after the seminal paper by Burkitt based on his work in Africa, it is appreciated that the contribution of viral infections to cancers remains considerably higher in sub-Saharan Africa than in the rest of the world.

Fighting against viral hepatitis: lessons from Taiwan

Viral hepatitis and its sequelae are important health problems worldwide, including Taiwan. For the last 40 years, Taiwan's scientists and health care providers have worked hard to control these sequelae, and the results have been excellent. The author, Ding-Shinn Chen, had a key role in planning and establishing the control program in Taiwan, and participated in the endeavors from the very beginning. In this perspective, he describes how he became interested in research as a medical student, his encounters with hepatitis B and C, how he and his colleagues started early detection of hepatocellular carcinoma (HCC), how he helped Taiwan's government create and implement the Viral Hepatitis Control Program, and how the effectiveness of the program in the decrease of hepatitis B carriage and HCC was monitored. He also discusses how he pioneered the use of interferon-α plus ribavirin to treat chronic hepatitis C. Hepatitis B viral load as a risk factor for HCC and cirrhosis in hepatitis B surface antigen carriers is reviewed briefly, as is the prevention of sequelae by antiviral therapies. Finally, Dr. Chen discusses unresolved issues that must be addressed and predicts the changes of the patterns of liver disease in Taiwan beyond the mid-21st century, which is in part affected by the fight against viral hepatitis that was initiated in the early 1980s.

CONCLUSION

Dr. Chen's perspective illustrates Taiwan's fight against viral hepatitis over the last 40 years. This experience can be shared by other countries in which the disease is equally prevalent.

[History of viral hepatitis]

INTRODUCTION

The history of viral hepatitis goes back thousands of years and is a fascinating one. When humans were first infected by such agents, a natural repetitive cycle began, with the capacity to infect billions of humans, thus decimating the population and causing sequelae in thousands of lives.

METHODS

This article reviews the available scientific information on the history of viral hepatitis. All the information was obtained through extensive bibliographic review, including original and review articles and consultations on the internet.

RESULTS

There are reports on outbreaks of jaundice epidemics in China 5,000 years ago and in Babylon more than 2,500 years ago. The catastrophic history of great jaundice epidemics and pandemics is well known and generally associated with major wars. In the American Civil War, 40,000 cases occurred among Union troops. In 1885, an outbreak of catarrhal jaundice affected 191 workers at the Bremen shipyard (Germany) after vaccination against smallpox. In 1942, 28,585 soldiers became infected with hepatitis after inoculation with the yellow fever vaccine. The number of cases of hepatitis during the Second World War was estimated to be 16 million. Only in the twentieth century were the main agents causing viral hepatitis identified. The hepatitis B virus was the first to be discovered.

CONCLUSIONS

In this paper, through reviewing the history of major epidemics caused by hepatitis viruses and the history of discovery of these agents, singular peculiarities were revealed. Examples of this include the accidental or chance discovery of the hepatitis B and D viruses.

Human tumor-associated viruses and new insights into the molecular mechanisms of cancer

The study of acute-transforming retroviruses and their oncogenes and of the multiple mechanisms deployed by DNA viruses to circumvent the growth-suppressive and proapoptotic function of tumor suppressor genes has provided the foundation of our current understanding of cancer biology. Unlike acute-transforming animal viruses, however, human tumor-associated viruses lead to malignancies with a prolonged latency and in conjunction with other environmental and host-related cooperating events. The relevance of viral infection to human cancer development has often been debated. We now know that at least six human viruses, Epstein-Barr virus (EBV), hepatitis B virus (HBV), hepatitis C virus (HCV), human papilloma virus (HPV), human T-cell lymphotropic virus (HTLV-1) and Kaposi's associated sarcoma virus (KSHV) contribute to 10-15% of the cancers worldwide. Hence, the opportunity exists to fight cancer at the global scale by preventing the spread of these viruses, by the development and distribution of effective and safe antiviral vaccines, and by identifying their oncogenic mechanism. Here, we discuss the molecular events underlying the neoplastic potential of the human tumor-associated viruses, with emphasis on the enigmatic KSHV and its numerous virally hijacked proangiogenic, immune-evasive and tumor-promoting genes. The emerging information may facilitate the development of new molecular-targeted approaches to prevent and treat virally associated human malignancies.

Prospective assessment of donor blood screening for antibody to hepatitis C virus and high-titer antibody to hepatitis B core antigen as a means of preventing post-transfusion hepatitis

Since November 1989, the Japan Red Cross has been screening blood donors for hepatitis C virus antibody (anti-HCV) with 1st generation assay and high-titer antibody to hepatitis B virus core antigen (HBcAb). To clarify the effectiveness of the new screening tests for the prevention of post-transfusion hepatitis, the incidence of post-transfusion hepatitis after the introduction of new tests (December 1989 to September 1990) was compared with the incidence before the in introduction (January 1982 to December 1987). The incidence of "definite" post-transfusion hepatitis was 10.3% (205/1991) with a mean transfusion volume of 10.2 units before the screening, and 3.9% (11/282) with a mean transfusion volume of 14.6 units after the introduction of the new screening tests. Statistical analysis revealed a significant decrease of post-transfusion non-A, non-B hepatitis after the introduction of new tests (chi 2 = 10.9, P < 0.01). The incidence of "probable" post-transfusion hepatitis was 12.4% (246/1991) and 11.7% (33/282) respectively. No significant change was observed between the rates of "probable" post-transfusion hepatitis before and after the introduction of the new tests. It was concluded that anti-HCV and high-titer anti-HBc screening of volunteer blood donors could contribute to the prevention of the post-transfusion non-A, non-B hepatitis in Japan.

Isolation of a complementary DNA fragment of hepatitis C virus in Taiwan revealed significant sequence variations compared with other isolates

To clone and characterize hepatitis C virus strains present in Taiwan, RNA was extracted from liver tissue collected from a patient during the acute phase of posttransfusion non-A, non-B hepatitis. RNA was then subjected to complementary DNA synthesis and the polymerase chain reaction, using primers derived from the original nucleotide sequence of the United States hepatitis C virus strain. A complementary DNA clone, HCV-T3, containing 552 base pairs of hepatitis C virus complementary DNA sequences was isolated and characterized. The homologies in nucleotide sequence between the Taiwan isolate and either the United States or Japan isolate were 80.1% and 91.5%, respectively. However, most of the nucleotide changes occurred in the third base positions, resulting in much higher homologies in amino acid sequence of 91.8% and 97.3%, respectively. Amplification of the less conserved region of hepatitis C virus genome with the polymerase chain reaction was improved by use of primers with nucleotides matched to the local strain. Finally, in addition to the liver and serum, the viral genome was also demonstrated in the spleen tissue by similar methods, suggesting another possible target for hepatitis C viral infection. These findings indicate that there is considerable heterogeneity in hepatitis C virus genomes isolated from different areas of the world.

Transfusion-associated hepatitis B: past and present

Thus, it can be concluded that: (1) Hepatitis B, even before the introduction of donor screening for HBsAg, probably never accounted for more than one-quarter of all cases of transfusion-associated hepatitis. (2) As of 1988, the frequency of this viral infection in blood recipients, now that sensitive donor screening for HBsAg is routine, is less than 10%. The exception are multiply transfused populations, such as hemophiliacs, the majority of whom have evidence of current or past exposure to hepatitis B. However, new inactivation procedures are likely to reduce the attack rate in virgin populations of hemophiliacs. (3) Interdiction of paid blood has proved far more effective than donor screening for HBsAg in reducing the overall frequency of transfusion-associated hepatitis. (4) The current requirement that all donors be screened for anti-HBc and ALT as surrogate markers of non-A, non-B hepatitis infection, and for anti-HIV, is likely to reduce the hepatitis B attack rate even more, perhaps to near zero. (5) The long-term outcome of transfusion-associated hepatitis B has not been determined, a task that will remain difficult to accomplish because of the paucity of current cases. Information in this regard will need to be derived from the recall and reevaluation of pedigreed patients who participated in prospective studies that were conducted in the distant past.

Elevated serum transaminase values during therapy for acute lymphoblastic leukemia correlate with prior blood transfusions

Fifty-nine children treated with acute lymphoblastic leukemia (ALL) were evaluated for abnormalities of liver function in order to monitor chemotherapy-induced hepatotoxicity. Twenty-one patients (36%) had elevations of alanine aminotransferase (ALT) in a pattern consistent with either drug-induced hepatocellular injury or non-A, non-B (NANB) hepatitis. These 21 patients (Group 1) were compared with the other 38 children (Group 2) with regard to a number of clinical and laboratory characteristics. Patients in Group 1 were older (P = 0.002) and had lower platelet counts (P less than 0.001) and hemoglobin values (P = 0.075) at diagnosis than Group 2 patients. The median number of units of blood products transfused was significantly greater in Group 1 patients (9.0 versus 1.0 units, P less than 0.001). The two groups were similar with regard to chemotherapy regimens. Children with ALL who present at an older age and who have more marked anemia and thrombocytopenia require more blood transfusions and are more likely to develop elevated ALT values in a pattern consistent with acute or chronic NANB hepatitis. These findings suggest a predominant role of NANB posttransfusion hepatitis--rather than or in addition to chemotherapy-induced hepatic injury--as a cause for elevated ALT values in children with ALL. In view of the potentially serious consequences of NANB hepatitis, a change in transfusion support practices may be warranted.

Posttransfusion hepatitis in Toronto, Canada

Five hundred seventy-six consecutive patients from the surgical, obstetrical, and medical services who had received transfusions of volunteer blood were followed-up at regular intervals for 6 mo. Fifty-three (9.2%) developed acute posttransfusion non A, non B hepatitis. Forty-seven (89%) had an incubation period between 2 and 8 wk. The frequency was not related to the age or sex of the patient, the indications for transfusion, the type of surgery, anesthesia, the presence of perioperative hypotension, or the number of units of blood transfused. There were no cases of fulminant hepatitis. Nineteen of the 53 patients (36%) with acute posttransfusion hepatitis progressed to chronic hepatitis. Development of chronic hepatitis was not related to the age or sex of the patient, the incubation period of the preceding acute hepatitis, the presence of shock or malignancy, or the number of units of blood transfused. Patients with higher levels of alanine aminotransferase during the acute hepatitis were more prone to develop chronic hepatitis. The finding of 9.2% of transfusion-related hepatitis in recipients of hepatitis B surface antigen-screened blood from volunteer donors underscores the potential sequelae of blood transfusion, especially as a source of contribution to the pool of chronic liver disease.

Acute viral hepatitis in Lebanon: evidence for a HAV-like non-A non-B hepatitis

Ninety-three cases of acute viral hepatitis in adult Lebanese patients were followed-up prospectively for a period ranging from 6 to 18 months. These included 33 hepatitis A (HAV), 32 hepatitis B (HBV) and 21 non-A, non-B hepatitis (NANB) cases. The clinical and seroepidemiologic characteristics of the three types were evaluated. HAV was characterized by a short prodroma (less than 1 week) and a high IgM level. HBV did not differ from similar cases reported in the Western world except for a complete absence of male homosexuals and drug addicts as a possible route of transmission. NANB hepatitis in Lebanon is mainly a sporadic infection similar to HAV except that the prodromal phase is prolonged (greater than 14 days) and IgM levels are within normal limits. The failure to develop chronicity in NANB suggests that the virus of sporadic NANB may be different from that which causes post-transfusional (PTH) NANB.

Non-A, non-B hepatitis: a prospective study of a hemodialysis outbreak with evaluation of a serologic marker in patients and staff

An outbreak of non-A, non-B hepatitis (NANBH) in a hemodialysis unit was prospectively studied and the clinical, biochemical, and serologic events were correlated with an experimental immunodiffusion assay for serum antigen and antibody. One hundred sixteen subjects (76 dialysis patients and 40 staff members) were studied over an 8-month period. Hepatitis was defined as two consecutive SGPT levels greater than two times the upper limit of normal occurring in two separate samples drawn greater than 7 days apart in the absence of other likely causes of liver disease. Weekly serum specimens were obtained and tested for SGPT, SGOT, alkaline phosphatase, bilirubin HBsAg, anti-HBc, anti-HBs, total anti-HAV, and anti-HAV IgM by commercial reagents, and for antigen and antibody by agar gel diffusion using reference reagents previously obtained from well-documented posttransfusion NANBH patients. Clinical evaluations were performed three times per week. Thirty patients and none of the staff developed NANBH. The NANBH patients were asymptomatic, except for two patients with jaundice. Fifteen of the 30 patients were positive for antigen which was detectable in at least one serum collected during the acute phase. Six patients and 10 staff without clinical NANBH or abnormal serology had antigen. Antigenemia was also observed in three patients with acute hepatitis B, with chronic hepatitis B in one patient and with alcoholic hepatitis in one patient. Thus, an antigen was detected in a high proportion of patients during the acute phase of NANBH, and it was also found in exposed patients who had other liver diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Diseases transmitted by blood transfusion

Except for post-transfusion hepatitis (PTH), the transmission of disease by blood transfusion appears to be very limited. There are only a few case reports documenting the transmission of malaria and other parasitic diseases, syphilis, or bacterial infections. The ability to eradicate PTH will depend on the development of sensitive-specific tests for the non-A, non-B agent(s). In the interim, two important steps that might be taken to reduce the incidence of PTH are the careful recruitment of blood donors and, most important, the judicious use of blood and its components.

An enzyme-linked immunosorbent assay for an antigen related to non-A, non-B hepatitis and its antibody: partial characterization of the antigen and chimpanzee transmission

An enzyme-linked immunosorbent assay (ELISA) was developed based on sera from patients convalescent from non-A, non-B hepatitis and haemophilia A patients who had been frequently treated with commercial blood products. Using this ELISA, an antigen was detected which appears to be related to non-A, non-B hepatitis. The antigen is provisionally designated as DS-antigen (DS-Ag). The serum of another patient with haemophilia A, which was strongly positive for the DS-Ag, caused a typical case of non-A, non-B hepatitis in a chimpanzee. DS-Ag could be detected in the serum of the chimpanzee during the acute phase of the infection. The ELISA for DS-Ag reacted with neither hepatitis A or B virus antigens, nor Epstein-Barr virus or cytomegalovirus. The assay was provisionally evaluated using sera from different groups of patients. Out of 17 patients with posttransfusion hepatitis non-A, non-B, 11 were found positive in the ELISA for DS-Ag (65%). As expected, a relatively high prevalence of DS-Ag (9%) was found in patients with haemophilia, who are regularly treated with blood-clotting factor-concentrates. Antibodies to DS-Ag were found in 48% of these patients. The DS-Ag was found in 8 of 1400 (0.6%) volunteer blood donors, and antibody to DS-Ag in 3% of the sera. Remarkably, a high incidence (41%) of antibodies to DS-Ag was found in prostitutes, suggesting that this antigen may be transmitted by a sexual route. The DS-Ag was pelleted by ultracentrifugation for four hours at 100,000g and was found to have a buoyant density of 1.32 g/cm3 in a CsCl gradient.

Two distinct types of non-A, non-B hepatitis in a cardiovascular surgical unit

The incidence of non-A, non-B hepatitis in a cardiovascular surgical unit was examined among the 204 patients who received blood transfusion and extracorporeal circulation while undergoing open heart surgery during April 1979 to December 1981. Among 115 adult patients (20 to 69 years old) 46 (43%) developed non-A, non-B hepatitis, whereas the incidence in younger patients (1 to 19 years old) was much lower (21.8%, 19 out of 89). When monthly incidence was examined during the study period, two nosocomial epidemics, the first during September 1979 to February 1980 and second during October 1980 to January 1981, were found. When clinical features such as maximum ALT level and the proportion of icterus were examined, the features of the above two epidemics were taken to be different from those consistently observed through the study period. The epidemic type hepatitis not only resulted in more severe clinical features than the nonepidemic type, but the sera of the former contained immune complexes at a higher rate (80%) than did the latter (7.6%).

A risk index for the prediction of the incidence of non-A, non-B posttransfusion hepatitis in open-heart surgery patients

Risk factors related to the occurrence of non-A, non-B posttransfusion hepatitis (PTH) were statistically analyzed in 204 patients (115 adults and 89 children) who received blood transfusion and extracorporeal circulation during open-heart surgery. The PTH incidence, irrespective of age or body weight, was affected by both transfusion volume and circulation time, ie, the incidence increased cumulatively with the increment of these two variables. Based upon such statistical analysis, a "PTH-risk index," from which one can objectively predict the probability of PTH, was devised by the summation of standardized transfusion volumes (Vs) and circulation time (Ts). As a result, a high correlation between the obtained PTH-risk index and actual incidence was found. The obtained straight regression line between PTH-risk index and the actual incidence rate enabled us to predict the incidence of PTH in open-heart surgery patients.

Hepatitis A virus: virologic, clinical, and epidemiologic studies

The last decade has borne witness to accelerated expansion of our understanding of hepatitis A virus. The agent of type A hepatitis is an RNA virus with a mean diameter of 27 nm. and biochemical-biophysical properties of an enterovirus. A variety of sensitive specific serologic techniques have been developed with which to identify hepatitis A virus and antibody, and both chimpanzees and marmosets have been studied extensively as experimental animal models. As a result of these studies, in vitro cultivation of hepatitis A virus has finally been accomplished, and a commercial radioimmunoassay for IgM antibody to hepatitis A virus has been developed for the rapid diagnosis of hepatitis A virus infection during acute illness. Clinically the illness caused by hepatitis A virus is relatively mild, often subclinical, and of limited duration and does not progress to chronic liver disease. This relative clinical benignity is reflected, according to preliminary histologic observations, in the sparing of the centrozonal area of the liver lobule. Rarely, however, hepatitis A virus can cause fulminant hepatitis. Type A hepatitis is transmitted almost exclusively by the fecal-oral route, and its spread is enhanced by epidemiologic settings favoring dissemination of enteric infections. Hepatitis A virus does not contribute to transfusion associated or other types of percutaneously transmitted hepatitis. Exposure to the virus increases as a function of age and decreasing socioeconomic class, but the incidence of hepatitis A virus infection in urbanized societies is decreasing. There is no evidence for the existence of chronic hepatitis A virus carriage; natural perpetuation of hepatitis A virus in urban communities appears to depend on a reservoir of nonepidemic, clinically inapparent cases. Until a vaccine, now being developed, becomes available, prevention of hepatitis A virus infection will continue to depend on maintenance of high standards of environmental and personal hygiene and on timely administration of immune serum globulin. Such prophylaxis may confer long lasting passive-active immunity but more frequently prevents infection entirely.

Acute hepatitis non-A, non-B following administration of factor VIII concentrates

A retrospective survey on clinical hepatitis in patients with bleeding disorders was performed. Nine episodes of hepatitis non-A, non-B occurred in 8 out of 20 patients (40%) with mild hemophilia A or von Willebrand's disease, who had been treated with commercial factor VIII concentrates. Only two episodes of hepatitis B occurred during the study period. The non-A, non-B attack rate after the first treatment was 40% with factor VIII concentrate obtained from large plasma pools (= 2,000 donors) including professional plasma donors as compared to 8% after treatment with factor VIII concentrate obtained from smaller (100-250 donors) plasma pools from Scandinavian donors.

Non-A, non-B hepatitis in West London

Acute and convalescent sera from 368 patients drawn from a 3-year survey of viral hepatitis in West London were tested for radioimmunoassay for evidence of recent infection with hepatitis A or B and, if neither was found, antibody to Epstein-Barr (EB) virus and cytomegalovirus. In 215 patients (58%) there was evidence of hepatitis A, in 98 (27%) hepatitis B, and in 5 both A and B. 2 patients with evidence of recent EB virus infection were excluded, leaving 48 (13%) attributed to non-A, non-B hepatitis. This illness was milder than hepatitis B as judged by duration of jaundice and peak serum bilirubin alanine-aminotransferase levels. The ratio of men to women was 1.4 to 1, but there was an excess of women in their twenties, most of whom were single. Only one had received blood, and none was a drug addict.

Immunoprophylaxis of viral hepatitis

Emergency physicians frequently encounter patients who have been or may have been exposed to viral hepatitis, and are often in a position to offer immunoprophylaxis. Needlestick exposure among hospital employees is endemic in any large hospital. Currently treatment of clinical hepatitis is only symptomatic; rational immunoprophylaxis is the only method available to influence the course of the disease. The basic types of viral hepatitis are reviewed, as are transmission of the disease, serologic tests, high risk groups, and immunoprophylactic agents. Treatment plans are outlined for different types of exposure, and an algorithm is included for management of needlestick exposure.

Viral hepatitis and the drug cult: a brief socio-epidemiological study in Sydney

Study of 141 individuals attending a Sydney drug referral centre revealed considerable psychosocial maladjustment in the group. Seventy-five per cent showed serological evidence of hepatitis B virus infection, past or present, as compared with 13% of control subjects. Antibody to hepatitis B core antigen was found to be twice as frequent as a serological marker of HBV infection, as antibody to hepatitis B surface antigen. Prevalence rates of antibody to hepatitis A virus were similar in the drug and control groups. Hepatitis possibly due to hepatitis non A non B virus infection, was found in 14% of those with clinical and biochemical hepatitis at the time of the study.

Hepatitis. A review of the disease and its significance to dentistry

The report is a review of the literature related to hepatitis B and its implications for dental practitioners. Hepatitis B represents a serious health risk among dentists and simple preventive measures can greatly reduce the risk of transmission or contraction of the disease. Certain positive findings in a healthy history should alert the dentist that he may be treating a carrier of hepatitis B. If so, the wearing of gloves, a mask and protective eyewear will almost totally protect one from contracting the disease. To guard against transmission of hepatitis B to other patients in the dental practice, all instruments should be sterilized and all environmental surfaces should be appropriately treated. A person with a confirmed exposure to hepatitis B should be inoculated with immune serum globulin.

Non-A, non-B hepatitis in patients receiving blood products

A group of patients all regularly receiving blood products for a congenital bleeding disorder were investigated for evidence of past infection with hepatitis A and B, and compared with a control group. There was a significantly higher percentage of the test group who had markers of infection with these viruses, and 15 patients had symptoms of hepatitis during the study. The greater number of the test group showing evidence of past hepatitis A infection can only really be explained by acquiring antibody from blood products, especially since none of our patients with hepatitis had hepatitis A and there is evidence that this is not an infection associated with blood products. We conclude that the majority of patients in our study showing symptoms of hepatitis had non-A, non-B hepatitis.

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.

Serological markers for hepatitis types A and B among U.S. Arym soldiers, Germany

Viral hepatitis rates among U.S. Army soldiers in Europe have been found to be two to three times higher than corresponding rates for soldiers stationed in the U.S. Sera from 89 per cent of a representative Army unit with 865 members and a known hepatitis problem were tested for HBsAg, anti-HBs, anti-HBc, and anti-HA. The prevalence of HB markers was 20 per cent, and hepatitis A antibody was present in 25 per cent. A six-month follow-up, conducted on 260 individuals initially negative for all four tests, revealed that 11 of these were now HB seropositive, whereas none had seroconverted to anti-HA positive. The HB virus was the principal agent responsible for hepatitis in the unit surveyed.

Hepatitis after the transfusion of frozen red cells and washed red cells

The large-scale use of frozen red cells and washed red cells in this transfusion service has not been effective in reducing post-transfusion hepatitis. Seventy-eight per cent of 31,125 transfusions, excluding platelets and plasma, were given in the form of frozen or washed red cells. These transfusions were associated with 56 cases of hepatitis. In 37 cases, the recipients had received only frozen or washed red cells (or both). Post-transfusion hepatitis was of the non-A, non-B type in 95% of cases. On average, commercial blood accounted for 30 per cent of the donor base during the first four years and was involved in 44 of the 56 cases. Elimination of commercial blood from the donor base resulted in a decrease in the incidence of hepatitis from 2.1 to 0.3 per 1000 transfusions.

Circulating immune complexes in non-A, non-B hepatitis. Possible masking of viral antigen

Serial serum samples from 22 patients with transfusion-associated non-A, non-B hepatitis and 2 chimpanzees with the experimentally induced disease were tested for circulating immune complexes by Raji-cell radioimmunoassay. 13 patients (59%) and 1 chimpanzee had circulating immune complexes immediately before, coincident with, or during the return to normal of raised aminotransferase activity. 7 of the 10 patients with chronic non-A, non-B hepatitis had detectable complexes at levels which waxed and waned in parallel with changes in serum aminotransferase activity. Immune complexes may contain and mask viral antigens, and their presence may explain the failure of conventional immunological techniques to detect virus antigens.

Non-A non-B hepatitis associated with chronic liver disease in a haemodialysis unit

To clarify the aetiology of an outbreak of HBsAg-negative acute hepatitis in the renal unit at Fulham Hospital in 1968--70, serological tests for antibody to hepatitis-A virus (anti-H.A.V.) were done retrospectively on serum samples obtained at the time of the outbreak. 7 patients had had two previous episodes of clinical HBsAg-negative hepatitis. Serum samples were available from 24 of the 29 infected patients, and these were paired in 12 instances. There was a slight increase in the titre of anti-H.A.V. in 1 patient, and a further 2 patients who subsequently developed chronic hepatitis showed a decrease in titre, but no changes in titre were detected in the remaining 21 cases. These findings do not provide evidence for the involvement of hepatitis-A virus in the outbreak of hepatitis and effectively exclude a role for this virus in the chrnoic liver disease which developed subsequently in 8 (28%) of the patients. This outbreak is therefore probably non-A non-B hepatitis, which has not been reported previously in Great Britain in a haemodialysis unit. The results confirm that this form of hepatitis may be related to a high frequency of persistent hepatic dysfunction.

Haemagglutination assay for HBsAg -- a new approach to reagent preparation

Human group O rhesus negative erythrocytes were spherocyted and fixed in glutaraldehyde, then coated initially with HBsAg and subsequently with anti-HBs. The resulting reagent was found to agglutinate in the presence of HBsAg positive serum, but not in HBsAg negative serum. The assay was evaluated for blood donor screening (39,962 donations) over a 6-month period, and was compared with Hepatest (RPHA) and AUSRIA-2 (RIA) for the study of two established HBsAg panels.

Prevalence of hepatitis A and B infections in multiply transfused thalassaemic patients

Evidence of hepatitis B virus (HBV) and hepatitis A virus (HAV) infections was south in 148 multiply transfused patients with thalassaemia and in healthy controls (2040 for HBV and 217 for HAV). The prevalence of the HBV surface antigen or antibody to it was significantly higher in patients than in controls and increased with the number of blood transfusions. In contrast, the prevalence of antibody to HAV was significantly lower in patients than in controls and decreased with the number of blood transfusions. These results support the view that blood transfusion does not play any appreciable part in transmitting HAV. Indeed, regular blood transfusion, where donors almost all have HAV antibody, seems to give protection against infection.

The epidemiological pattern of hepatitis A, B, and non-A, non-B in Sweden

In a clinical series of 148 patients with acute hepatitis, serological analysis of hepatitis A and hepatitis B markers revealed 16% of the cases as hepatitis type non-A, non-b. Hepatitis A was diagnosed in 27% of the patients with drug addicts as the predominating category, while serological evidence of hepatitis B infection was found in 57%, again with drug addicts in the majority. Drug addicts also predominated among the non-A, non-B cases, and possibly this category of patients is today the main reservoir not only of hepatitis B but also of hepatitis A and non-A, non-B.