Risks associated with hepatitis A and hepatitis B in patients with hepatitis C.

Individuals with hepatitis C virus (HCV) are at risk for acquiring hepatitis A virus (HAV) or hepatitis B virus (HBV) because of shared risk factors. A number of organizations recommend vaccination against HAV and HBV for patients with HCV. The rationale for vaccinating these patients is to prevent hepatic superinfections. Acute HAV superinfection causes more severe disease, acute hepatic failure, and higher fatality rates in patients with underlying chronic liver disease, specifically chronic HBV infection and chronic HCV infection. Available data, although limited, suggest that HBV coinfection with HAV and HCV causes more severe hepatic injury than infection with HAV or HCV alone. At standard doses, hepatitis A and hepatitis B vaccines are safe and immunogenic in patients with mild-to-moderate hepatitis C or chronic liver disease. Regardless of disease severity, vaccination should be routinely administered to patients upon diagnosis of HCV infection. Early vaccination is important because response to vaccination is reduced as liver disease progresses. Prevaccination and postvaccination serology testing is recommended in specific populations. A new combination hepatitis A and hepatitis B vaccine has been shown to be as safe and effective as monovalent hepatitis A and B vaccines and is currently under review by the United States Food and Drug Administration. A combination vaccine would offer ease of administration and convenience and could increase compliance in patients with hepatitis C or other chronic liver disease: two groups that should be more aggressively targeted by healthcare professionals.     

Incidence of HAV and HBV infections and vaccination rates in patients with autoimmune liver diseases

OBJECTIVES: Hepatitis A virus (HAV) or hepatitis B virus (HBV) superinfection is associated with an increased mortality in patients with chronic liver diseases (CLD). Despite official recommendations, it was reported that the vaccination rate against HAV is low in patients with chronic hepatitis C infection. To evaluate the situation in patients with autoimmune liver diseases, we conducted a retrospective cohort study. METHODS: Susceptibility to HAV and HBV infections, course of HAV and HBV infections, vaccination rates against HAV and HBV, and efficacy of hepatitis A/B vaccines were evaluated by antibody testing in 225 patients with autoimmune liver diseases during 1,677 person-years. RESULTS: Susceptibility to HAV/HBV infection was 51/86%. Incidence of HAV/HBV infection was 1.3/1.4 per 1,000 person-years. One HAV infection occurred, but the patient recovered spontaneously. Two patients were HBV-infected after receiving an anti-HBc-positive (antibody to hepatitis B core antigen) donor graft during orthotopic liver transplantation, and one of them developed chronic HBV infection. Vaccination rates were 11% (HBV) and 13% (HAV), respectively. Seventy-six percent of the vaccinated patients (HBV vaccine) developed anti-HBs (antibody to hepatitis surface antigen) >or=10 UI/L. Ten out of 13 vaccinated patients, showing a low or nonresponse to hepatitis B vaccine, had concomitant immunosuppressive therapy. Anti-HAV was detectable in all patients after administration of HAV vaccine. CONCLUSIONS: Patients with autoimmune liver diseases have a high susceptibility to HAV and HBV infections. Vaccination rates are low in this patient cohort and efficacy of hepatitis B vaccine is reduced due to immunosuppressive therapy. Improving adherence to vaccine recommendations is essential to prevent HAV and HBV infections in patients with autoimmune liver diseases.     

High incidence of viral hepatitis among American missionaries in Africa

Protestant missionaries (n = 360) serving in sub-Saharan Africa between 1967-1984 were studied to determine the risk of hepatitis A virus (HAV) and hepatitis B virus (HBV) infection. Personnel were serologically screened for antibody to both the hepatitis A virus (anti-HAV) and the surface antigen to the hepatitis B virus (anti-HBs) prior to departure, periodically during service abroad, and upon completion of their African tour. Rates of seroconversion were used as measures of the incidence of infection. Prior to service, 16% of the staff had anti-HAV and 3% had anti-HBs; post-service rates were 42% and 26%, respectively. Over 90% of the staff with greater than 20 years of service were seropositive for anti-HAV. For both viruses, the infection rate was highest during the first 1-2 years of service, when 28% of those susceptible to HAV and 11% of those susceptible to HBV became infected. Over the next decade, the median annual attack rate was 5.4% for HAV and 4.2% for HBV. Differences in the missionary HBV infection rate among the various African nations served tended to reflect differences in the magnitude of chronic HBV carriage among indigenous population groups. We conclude that missionaries to sub-Saharan Africa are at enhanced risk of both HAV and HBV infection, and that all should receive passive immunization with immune globulin and active immunization with hepatitis B vaccine.     

Induction or expansion of T-cell responses by a hepatitis B DNA vaccine administered to chronic HBV carriers

Despite the availability of effective hepatitis B vaccines for many years, over 370 million people remain persistently infected with hepatitis B virus (HBV). Viral persistence is thought to be related to poor HBV-specific T-cell responses. A phase I clinical trial was performed in chronic HBV carriers to investigate whether HBV DNA vaccination could restore T-cell responsiveness. Ten patients with chronic active hepatitis B nonresponder to approved treatments for HBV infection were given 4 intramuscular injections of 1 mg of a DNA vaccine encoding HBV envelope proteins. HBV-specific T-cell responses were assessed by proliferation, ELISpot assays, and tetramer staining. Secondary end points included safety and the monitoring of HBV viraemia and serological markers. Proliferative responses to hepatitis B surface antigen were detected in two patients after DNA injections. Few HBV-specific interferon gamma-secreting T cells were detectable before immunization, but the frequency of such responses was significantly increased by 3 DNA injections. Immunization was well tolerated. Serum HBV DNA levels decreased in 5 patients after 3 vaccine injections, and complete clearance was observed in 1 patient. In conclusion, this study provides evidence that HBV DNA vaccination is safe and immunologically effective. We demonstrate that DNA vaccination can specifically but transiently activate T-cell responses in some chronic HBV carriers who do not respond to current antiviral therapies.     

Response to Hepatitis A and B Vaccine Alone or in Combination in Patients with Chronic Hepatitis C Virus and Advanced Fibrosis

Patients with advanced fibrosis are at increased risk of severe outcomes if they develop acute infection with hepatitis A (HAV) or hepatitis B (HBV) viruses. There are no data on the efficacy of combined HAV/HBV vaccination in patients with advanced fibrosis. Our aim was to evaluate the response to the HAV and HBV vaccine alone or in combination for patients with chronic hepatitis C (HCV) and advanced fibrosis and to evaluate the impact of administering the vaccine while patients were receiving peginterferon for treatment of chronic HCV. In this prospective study of patients with advanced fibrosis (Ishak 3–6), those without serologic evidence of prior exposure were vaccinated with either Havrix^? HAV, Engerix^? HBV, or the TWINRIX^? HAV/HBV combination vaccine as appropriate, and response was defined as the development of anti-HAV or anti-HBV surface antibodies. Of the 162 eligible patients, the prevalence of prior exposure to HAV and HBV was 30 and 18%, respectively. Of the 84 patients vaccinated, 38% received Havrix, 14% Engerix, and 48% TWINRIX^?. The response to the HAV vaccine was 75% in those receiving Havrix^? compared to 78% receiving TWINRIX^?. In contrast, the response to HBV vaccination was 42% in patients receiving Engerix^? compared to 60% in those vaccinated with TWINRIX^? (difference 18.3%; OR 0.29; 95% CI: 0.57–7.79). The presence of diabetes was the only risk factor identified for reduced HBV response (P = 0.01). Responses to both HAV and HBV vaccines when administered alone or in combination were lower than expected in patients with HCV and advanced fibrosis, especially in those with diabetes. The observation that the decline in HBV vaccine response was somewhat lower when this was administered alone as opposed to the combination A/B vaccine suggests that the administration of a combination vaccine may enhance the vaccination response to HBV.     

Hepatitis B vaccine: prophylactic, therapeutic, and diagnostic dilemma

Hepatitis B virus (HBV) remains a serious public health problem worldwide, accounting for high morbidity and mortality rates as well as significant personal, societal, and economic costs. Hepatitis B is a preventable disease; a safe and effective vaccine has been available for 30 years. The World Health Organization aims to control HBV worldwide by integrating HB vaccination into infant, possibly adolescent, and at-risk adult routine immunization programs. In recent years, a drastic reduction in the mortality and morbidity of chronic HBV, including hepatocellular carcinoma, has occurred, particularly in hyperendemic areas. In addition, a therapeutic vaccine that enhances patient immune response has been considered as a possible alternative to antiviral agents. However, mutant HBV may infect individuals who are anti-HBs positive after immunization (vaccine-escape) and/or fail for detection of HBsAg (diagnostic-escape), which may lead to transmission through donated blood or organs. This review attempts to summarize the prophylactic, therapeutic, and diagnostic concerns on HBV vaccines.     

Efficacy of virosome hepatitis A vaccine in young children in Nicaragua: randomized placebo-controlled trial

Immunization of young children could control hepatitis A virus (HAV) infection, but the efficacy of hepatitis A vaccines in early childhood is unknown. In a randomized, double-blind trial of a single dose of a virosome-formulated, aluminum-free inactivated HAV vaccine in Nicaragua, 274 children (age range, 1.5-6 years) received vaccine or placebo injections; 239 children seronegative for hepatitis A were included in the primary efficacy analysis. HAV infection documented by immunoglobulin M antibodies was the primary end point. Among children seronegative for hepatitis A, infection was diagnosed in 4 children in the vaccine group and 22 children in the placebo group (protective efficacy, 84.6%; 95% confidence interval, 54.7%-96.1%). All infections in children in the vaccine group occurred within 6 weeks. After 6 weeks, protective efficacy was 100% (79.8%-100%). In children in the placebo group, the incidence of HAV infection was 17.6 and that of icteric illness was 1.6 cases/100 person-years. Adverse effects were rare in both children in the vaccine group and children in the placebo group. A single dose of a hepatitis A virosome vaccine is safe and protects young children against HAV infection.     

衣原体疫苗的研究策略与进展

衣原体(Chlamydia)是一种专性胞内寄生菌,衣原体的反复感染及其诱发的严重后遗症是人类健康的巨大威胁,因此,迫切需要开发安全有效的疫苗来预防和控制衣原体感染.尽管人类在衣原体免疫保护机制的研究和疫苗开发方面已经取得了一定的突破,但是结合疫苗安全性和免疫效果的全面考量,有效衣原体疫苗的成功出世仍然面临很多问题.本文...     

Hepatitis B: evolving epidemiology and implications for control.

Control and the possible elimination of transmission of HBV infection is possible with the appropriate use of hepatitis B vaccines. The prevention of chronic HBV infection has the potential of reducing the association burden of chronic liver disease and primary hepatocellular carcinoma. Worldwide, strategies for the effective use of hepatitis B vaccine have been developed and are being implemented in those areas where childhood transmission is the predominant source of chronic HBV infections. However, in the United States and other areas with "low" rates of HBV infection, current vaccination strategies have not been effective and have not fully taken into account the multifaceted epidemiology of HBV infection in those areas. Unfortunately, the majority of infections occur among adults who have been the most difficult to access, who acquire infection before they realize they are at risk, and where the changing epidemiology of HBV infections among the various risk groups only emphasizes the problems of vaccine delivery. In addition, the majority of persons receiving vaccine as a result of the current strategy to immunize adult high-risk groups have been persons who acquire HBV infection through occupational exposure, a group that accounted for no more than 5% of cases even before vaccine was introduced. The failure of the current immunization strategy to prevent a disease with significant health care and economic consequences is beginning to cause a reevaluation of this approach. A comprehensive approach to eliminating HBV transmission must address infections acquired during early childhood as well as those acquired by teenagers and adults.(ABSTRACT TRUNCATED AT 250 WORDS)     

The cost-effectiveness of two strategies for vaccinating US veterans with hepatitis C virus infection against hepatitis A and hepatitis B viruses

OBJECTIVES: Although hepatitis A and B vaccinations are recommended for patients with chronic hepatitis C virus (HCV), the ideal vaccination strategy has not been determined. Our objective was to model the cost-effectiveness of two strategies for vaccinating patients with HCV infection against hepatitis A (HAV) and hepatitis B (HBV) viruses. The strategies evaluated were: universal vaccination with the combined HAV and HBV vaccine, and selective vaccination based on immunity determined by blood testing. METHODS: A decision tree model was constructed to compare the cost-effectiveness of the two vaccination strategies from the New Mexico Veterans Affairs Health Care System (NMVAHCS) perspective. A retrospective review of all HCV patients (2517 subjects) at the NMVAHCS was performed to extract prevalence of immunity to HAV and HBV, and prevalence of decompensated liver disease. Literature review was performed to obtain other probabilities for the model. Only direct medical costs were considered; the effectiveness measure was the number of patients immune to both HAV and HBV. Sensitivity analyses were performed to test robustness of the results to changes in input variables. All costs were in 2004 US dollars. RESULTS: The selective strategy was less costly but less effective, with a cost-effectiveness ratio of 105 dollars per patient immune to HAV and HBV. The universal strategy was more effective but more expensive with a cost-effectiveness ratio of 112 dollars per patient immune to HAV and HBV. Compared with the selective strategy, universal strategy was associated with an incremental cost-effectiveness (ICE) ratio of 154 dollars per additional patient immune to HAV and HBV. The universal strategy would become more cost-effective if 1) the cost of combined vaccine was reduced to less than 30.75 dollars (9.7% reduction), 2) the cost of HBV vaccine increased to greater than 34.50 dollars (25% increase), 3) the cost of blood tests for immunity increased to more than 25.25 dollars (23% increase), or (4) the prevalence of anti-HBs decreased to less than 24%. CONCLUSIONS: The selective vaccination strategy for HAV and HBV in our sample of patients with HCV is more cost-effective. However, the universal strategy is more effective and its ICE is minimal, thus it may be worth the additional cost.     

Antibody responses to hepatitis A virus vaccine in HIV-infected children with evidence of immunologic reconstitution while receiving highly active antiretroviral therapy

BACKGROUND: Human immunodeficiency virus (HIV)-infected patients have weak responses to vaccines and may require revised immunization regimens. We investigated the safety and immunogenicity of 2 doses of hepatitis A virus (HAV) vaccine followed by a booster dose in HIV-infected children receiving stable highly active antiretroviral therapy. METHODS: A total of 235 children with CD4+ T cell percentages > or = 20% received 2 vaccine doses 24 weeks apart, and 117 received a third vaccine dose after 104 weeks. Anti-HAV antibody titers were measured at baseline and at 32, 104, and 112 weeks after the first vaccination. Subjects with antibody titers > or = 20 mIU/mL were defined as being seropositive. High and low antibody responses were defined as titers > or = 250 and <250 mIU/mL, respectively. RESULTS: Of 151 subjects who were HAV seronegative at baseline, 97% seroconverted after 2 vaccine doses, and 47% had low antibody responses. At 104 weeks, 90% of subjects had antibody titers > or = 20 mIU/mL, and those with low antibody responses were more likely to lose protective antibody titers. A third vaccine dose generated significantly higher antibody titers than those observed after the second vaccine dose. Undetectable HIV RNA at baseline was associated with higher anti-HAV antibody titers after the second vaccine dose. Antibody titers after the second and third vaccine doses were weakly correlated with CD4+ T cell percentages at the time when each vaccine dose was administered. In the 45 subjects who were HAV seropositive at baseline, responses to 2 and 3 vaccine doses were higher than those in subjects who were HAV seronegative at baseline, but the responses showed similar correlations. There were no serious adverse events associated with the vaccine. CONCLUSIONS: HIV-infected children with CD4+ T cell percentages > or = 20% responded better to the HAV vaccine if they had undetectable HIV RNA. The standard 2-dose immunization regimen generated low antibody titers with limited persistence. A third vaccine dose was safe and increased the antibody titers, suggesting that an increase in immunizations may be warranted in this population.     

Unsolved problems and future perspectives of hepatitis B virus vaccination

Hepatitis B virus(HBV) infection is still a serious worldwide problem, and vaccination is the most effective strategy for primary prevention of the infection. Although universal vaccination may be required for total eradication, several countries, including Japan, have not yet adopted universal vaccination programs. Some individuals are non-responders to HBV vaccine and several mechanisms responsible for their poor response have been proposed. To overcome non-response, third generation vaccines with pre-S proteins have been developed. These vaccines have shown better antiHBs responses and may also be effective in preventing infection by HBV with S mutant. Improvement of vaccine efficacy by intradermal administration, or coadministration with cytokines or adjuvants, may also be effective in non-responders. The necessity, timing and method of booster vaccination in responders with decreased anti-HBs responses, and effective vaccination against S-mutant HBV, are issues requiring resolution in the global prevention of HBV infection.     

Hepatitis a in Lebanon: a changing epidemiological pattern

In this multicenter study in Lebanon, hepatitis A virus (HAV) seroprevalence rates were surveyed by age, gender, and socioeconomic factors. Blood samples collected from 606 subjects aged 1 to 30 years were analyzed for anti-HAV IgG. Age was the most important factor influencing HAV seroprevalence. HAV seroprevalence rates in the current study were about 78% in the > or = 21 years age group, 28% in the 6-10 years age group, and 11% in the 1-5 years age group as compared with 97.7% in adults, 85% in children aged 6-12 years, and 40% in children aged 1 to 5 years in previous studies, demonstrating a shift in HAV seroprevalence from the younger to the higher age groups. In light of the severity of the disease in adults and availability of safe and effective vaccines against HAV infection, introduction of HAV vaccination into the national immunization schedule of Lebanon should be considered.     

Therapeutic vaccination in chronic hepatitis B: preclinical studies in the woodchuck model

Summary.  Interferon-α and nucleoside analogues are available for the treatment of chronic hepatitis B virus (HBV) infection but do not lead to a satisfactory result. New findings about the immunological control of HBV during acute infection suggest the pivotal role of T-cell mediated immune responses. Several preclinical and clinical trials were undertaken to explore the possibility of stimulating specific immune responses in chronically infected animals and patients by vaccination. However, vaccination with commercially available HBV vaccines in patients and immunization in woodchucks with core or surface proteins of woodchuck hepatitis virus (WHV) did not result in effective control of HBV and WHV infection, suggesting that new formulations of therapeutic vaccines are needed. Some new approaches combining antiviral treatments with nucleoside analogues, DNA vaccines and protein vaccines were tested in the woodchuck model. It could be shown that therapeutic vaccinations are able to stimulate specific B- and T-cell responses and to achieve transient suppression of viral replication. These results suggest the great potential of therapeutic vaccination in combination with antivirals to reach an effective and sustained control of HBV infection.     

Insights into induction of the immune response by the hepatitis B vaccine

After more than four decades of hepatitis B virus (HBV) vaccine implementation, its safety and efficacy in preventing HBV infection have been proven and several milestones have been achieved. Most countries have included HBV immunization schedules in their health policies and progress has been made regarding universalization of the first HBV vaccine dose at birth. All of these actions have significantly contributed to reducing both the incidence of HBV infection and its related complications. However, there are still many drawbacks to overcome. The main concerns are the deficient coverage rate of the dose at birth and the large adult population that has not been reached timely by universal immunization. Additionally, the current most widely used second-generation vaccines do not induce protective immunity in 5% to 10% of the population, particularly in people over 40-years-old, obese (body mass index > 25 kg/m²), heavy smokers, and patients undergoing dialysis or infection with human immunodeficiency virus. Recently developed and approved novel vaccine formulations using more potent adjuvants or multiple antigens have shown better performance, particularly in difficult settings. These advances re-launch the expectations of achieving the World Health Organization’s objective of completing hepatitis control by 2030.     

Patients with inflammatory bowel disease are at risk for vaccine-preventable illnesses

BACKGROUND: Patients with chronic, immune-mediated conditions such as inflammatory bowel disease (IBD) are often treated with long-term immunosuppressive therapies, potentially increasing their risk of developing an infection. Empiric data suggest that vaccines are underutilized in immunocompromised patients, despite published guidelines recommending their use. We aimed to assess exposure risk and immunization status among patients receiving care in an IBD specialty clinic. METHODS: Patients completed a self-administered, pretested, structured questionnaire during a routine visit for the management of IBD. Survey questions related to medical and immunization histories, and exposures to known risk factors for influenza, pneumococcus, viral hepatitis, and varicella. Additionally, in a subgroup of patients who agreed to donate a sample of blood, immune status to hepatitis A (HAV), hepatitis B (HBV), and varicella was determined. RESULTS: Two hundred four patients were asked to participate in the study; 169 completed surveys and comprised the study population. Mean age was 35 yr (range 13-75 yr). One hundred forty-six respondents (86%) reported current or prior use of immunosuppressive medications. Only 45% of respondents recalled tetanus immunization within the past 10 yr, 41 (28%) reported regularly receiving flu shots, and 13 (9%) reported having received pneumococcal vaccine. The most common reasons for nonimmunization with influenza included lack of awareness (49%) and concern for side effects (18%). Responses indicated that 75 (44%) patients were at risk for HBV but only 47 (28%) had been vaccinated against the infection; of patients with previous HBV vaccination, only three of nine (33%) had measurable antibodies against hepatitis B surface antigen. CONCLUSIONS: Immunization against selected vaccine-preventable illnesses was uncommon in patients with IBD, despite the presence of significant risk factors. Efforts to improve immunization status among patients with IBD and other chronic, immune-mediated conditions are needed.     

VHA et VHE, une épidémiologie en évolution, une prophylaxie à adapter

Hepatitis A virus (HAV) and hepatitis B virus (HBV) are two non-enveloped RNA viruses, which cause acute hepatitis with no progression to chronic liver disease and no chronic carriage. This is why, for their survival, these two viruses have a particularly efficient transmission mechanism: the faecal-oral route. Despite this similarity, there are significant differences between HAV and HEV with respect to their viral characteristics, their epidemiology and their treatment. HAV is a member of the Picornaviridae, while HEV belongs to the small Hepeviridae family. Although several genotypes have been identified for these two viruses, only one serotype is recognized for each. For HAV, humans are the only reservoir. The infection is associated with poor sanitation. Socioeconomic improvements and better hygiene standards have reduced the transmission of HAV in developed countries. The mean age of exposure has increased, resulting in large numbers of teenagers and adults becoming susceptible to the virus. Unlike HAV, HEV is zoonotic. The virus is found in the faeces of many animals although pigs seem to be the main reservoir. Hepatitis E occurs predominantly in developing countries, resulting in large water-born epidemics. Person-to-person transmission is less frequent. In developed countries, most HEV infections are thought to be imported. In the last few years, increasing numbers of sporadic cases have been described in indigenous patients, while the seroprevalence ranges from 1 to 5%. This suggests that HEV may be more prevalent than previously considered in industrialized countries. Immunization with inactivated HAV vaccine results in highly effective, rapid and long-lasting immunity. The changing epidemiology of HAV infections in many countries should lead to a review of vaccination strategies. Several vaccines against HEV are currently undergoing evaluation in clinical trials.     

Hepatitis B virus epidemiology, disease burden, treatment, and current and emerging prevention and control measures

Hepatitis B virus (HBV) infection is a serious global health problem, with 2 billion people infected worldwide, and 350 million suffering from chronic HBV infection. The 10th leading cause of death worldwide, HBV infections result in 500 000 to 1.2 million deaths per year caused by chronic hepatitis, cirrhosis, and hepatocellular carcinoma; the last accounts for 320 000 deaths per year. In Western countries, the disease is relatively rare and acquired primarily in adulthood, whereas in Asia and most of Africa, chronic HBV infection is common and usually acquired perinatally or in childhood. More efficacious treatments, mass immunization programs, and safe injection techniques are essential for eliminating HBV infection and reducing global HBV-related morbidity and mortality. Safe and effective vaccines against HBV infection have been available since 1982. The implementation of mass immunization programs, which have been recommended by the World Health Organization since 1991, have dramatically decreased the incidence of HBV infection among infants, children, and adolescents in many countries. However, not all countries have adopted these recommendations and there remains a large number of persons that were infected with HBV prior to the implementation of immunization programs. Antiviral treatment is the only way to reduce morbidity and mortality from chronic HBV infection. Conventional interferon alfa and lamivudine have been the primary treatments to date. Conventional interferon alfa produces a durable response in a moderate proportion of patients but has undesirable side-effects and must be administered subcutaneously three times per week. Lamivudine also produces a response in a modest proportion of patients and causes few side-effects. However, prolonged treatment is often necessary to prevent relapse on cessation of therapy, and continuous treatment can lead to the development of lamivudine resistance. Promising emerging new treatments include adefovir, entecavir and peginterferon alfa-2a (40 kDa).     

Identification of acute vaccine-preventable hepatitis in individuals with chronic hepatitis in British Columbia between 1991 and 2007

BACKGROUND:

In British Columbia (BC), hepatitis A virus (HAV) and hepatitis B virus (HBV) vaccines are provincially funded for persons with chronic hepatitis infections.

PURPOSE:

To assess the effectiveness of BC public health follow-up of HBV and hepatitis C virus (HCV) cases and immunization policy by determining the number of vaccine-preventable acute hepatitis infections reported following a chronic HBV or HCV diagnosis, by examining demographic characteristics and by observing temporal trends.

METHODS:

All newly identified cases of HAV, HBV and HCV between 1991 and October 2007 were extracted from the BC integrated Public Health Information System and linked to ascertain cases of hepatitis suprainfection.

RESULTS:

Between 1991 and October 2007, 30 BC residents with chronic HBV and 104 with HCV were subsequently diagnosed with HAV. Acute HBV was identified in 162 persons previously diagnosed with HCV. Significantly more men than women developed hepatitis suprainfection (P<0.0001), but women were of a younger age when they were diagnosed with HAV (P=0.02) and acute HBV (P=0.0002). HAV suprainfection cases among those with HCV peaked in 1998 at 33 cases and declined to zero cases in 2007. In comparison, HBV suprainfection among individuals with chronic HCV peaked in 1996 at 26 cases and declined to two cases in 2007.

DISCUSSION:

Cases of HAV and acute HBV have declined among HCV-infected individuals. However, despite the availability of publicly funded vaccines for high-risk groups, a substantial number of acute HBV infections post-HCV identification are still identified, indicating that follow-up and vaccination coverage should be improved in these populations.     

Asian perspectives on viral hepatitis A

Abstract Recent decades have witnessed a marked decline in the prevalence of hepatitis A virus (HAV) infection in Asian populations, especially in children. This is attributable to general improvements in socio-economic status and hygiene, which have, in turn, made a large population of young adults susceptible to the disease. The HAV infection rarely results in death and mortality is age-dependent. According to previous reports, it may be more severe in persons with underlying chronic liver disease (CLD). Because most parts of Asia are areas of endemic hepatitis B and C virus infection, where chronic hepatitis B and C are the most important causes of CLD, it is therefore imperative for patients with CLD to be protected against HAV infection. Several studies have been conducted into the success of immunization against HAV in different risk groups. Given the increasing potential for HAV epidemics and the success and safety of the HAV vaccines, mass immunization against the infection seems possible and rational in Asia.