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.     

Vaccination against hepatitis b in patients with chronic liver disease

The prevalence of chronic liver disease is increasing, while at the same time, many at-risk populations are witnessing a resurgence of hepatitis B virus (HBV) infection. Thus, more patients are likely to have multiple causes of liver disease, as risk factors often overlap. Such patients may develop either acute viral hepatitis superimposed on pre-existing chronic liver disease or chronic infection with two hepatitis viruses. Patients with chronic HBV and hepatitis C virus coinfection have more severe laboratory abnormalities, more hepatic fibrosis, and greater frequency of cirrhosis, in addition to more complications of cirrhosis and a higher incidence of hepatocellular carcinoma. Acute hepatitis B superimposed on chronic hepatitis C may result in fulminant hepatitis, although this outcome is not as well proven as the increased morbidity of chronic hepatitis B and C coinfection. Both acute and chronic coinfection with HBV can be prevented. Vaccines for hepatitis B are safe in patients with chronic liver disease of a variety of causes and are effective, particularly if used early. Early vaccination against hepatitis B, as well as hepatitis A, should be part of the routine management of chronic liver disease.     

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.     

Current issues in the management of paediatric viral hepatitis

Viral hepatitis poses important problems for children. In preschoolers, hepatitis A virus (HAV) infection frequently causes acute liver failure. Vaccinating toddlers against HAV in countries with high endemicity is expected to decrease mortality. HAV vaccine demonstrates efficacy (comparable to immunoglobulin) as post‐exposure prophylaxis. A recently developed vaccine against hepatitis E virus (HEV) may benefit fetal health, because pregnant women are most prone to acute liver failure as a result of HEV. Hepatitis B vaccine continues to demonstrate value and versatility for preventing serious liver disease. With chronic infection, undetectable levels of serum HBV DNA complement e‐seroconversion as the preferred outcome measure; suppressed viral load correlates with long‐term complications better than HBeAg status. Among Taiwanese children, low pretreatment HBV DNA (<2 × 10⁸ copies/ml) strongly predicted response to interferon‐α. Future paediatric studies must incorporate HBV DNA levels. The rationale for routine treatment of immunotolerant hepatitis B during childhood remains uncertain. Any treatment of chronic hepatitis B in childhood requires consideration of the risks and benefits. Childhood hepatitis C virus (HCV) infection results mainly from mother‐to‐infant transmission. Babies of HCV‐infected women should be tested for serum HCV RNA at 1 month of age. If negative, confirmatory anti‐HCV antibody testing may be performed between 12 and 15 months of age. Children with chronic hepatitis C may develop progressive fibrosis/cirrhosis, particularly in the setting of obesity and insulin resistance. Treatment of children chronically infected with genotype 2 or 3 is highly successful: combination therapy of pegylated interferon‐α and ribavirin is well tolerated and superior to pegylated interferon‐α alone.     

A virological perspective on the need for vaccination

Superinfecton of chronic carriers of hepatitis B virus (HBV) or hepatitis C virus (HCV) with hepatitis A virus (HAV) is often associated with more severe liver disease than infection with HAV alone. Superinfection commonly causes markers of HBV and HCV replication to fall to significantly lower levels. The pathogenesis of acute liver damage characteristic of viral hepatitis is thought to be mediated by host cytotoxic T-lymphocytes (CTLs) directed against virus-infected hepatocytes. It has been proposed that the more aggressive liver disease observed in individuals infected with HAV in addition to chronic HBV/HCV is a result of the induction of interferon (IFN)-alpha during acute HAV infection. This accounts for the antiviral effect on the active markers of HBV/HCV replication, and the enhanced CTL response against HBV/HCV-infected hepatocytes. Alternatively, HAV may indirectly stimulate the T helper 1 (Th1)-type cytokine responses, such as interleukin (IL)-2, IFN-gamma and tumour necrosis factor (TNF)-alpha, which directly promote the antiviral CTL response. Clearance of HBV infection, and possible HAV and HCV, is associated with a specific CTL response, while viral persistence in chronic HBV and HCV infection has been attributed to an imbalance in the Th1-Th2 arms of the immune response. Vaccination against hepatitis A should be considered for patients with chronic HBV/HCV infection, to minimize the risk of exacerbating underlying liver disease.     

Susceptibility to hepatitis A in patients with chronic liver disease due to hepatitis C virus infection: missed opportunities for vaccination

Hepatitis A virus (HAV) superinfection is associated with a high risk of liver failure and death in patients with underlying chronic liver disease. Although HAV vaccination is recommended for all patients with chronic hepatitis C virus (HCV) infection, little is known about adherence to these recommendations in clinical practice. The aims of this study were to determine the frequency of HAV testing and vaccination among patients with chronic HCV infection. We conducted a retrospective cohort study of 1,193 patients diagnosed with chronic HCV infection over a 1-year period. During 1,646 person-years of follow-up, patients were seen by their primary care provider a median of 10.0 times (interquartile range, 4.0-20.0). HAV antibody testing was performed in 640 subjects (53.6%), and 317 (49.5%) of those tested were susceptible (HAV antibody negative). Only 94 of the 1,193 patients (7.9%) received the HAV vaccine, including 26.8% of the 317 susceptible patients, 0.9% of the 323 patients who were already immune to HAV, and 1.1% of the 553 subjects who were never tested. Among the 94 vaccinated patients, 45 received only one dose of the vaccine. Three of the unvaccinated patients developed acute HAV infection during follow-up, and 1 of them died of acute liver failure. In conclusion, despite published recommendations to vaccinate against HAV in patients with chronic HCV infection, we found that HAV testing and vaccination rates were low in clinical practice. Public health programs to increase awareness about HAV vaccination in patients with chronic liver disease are needed.     

Epidemiology, natural history, and treatment of hepatitis B virus and hepatitis C virus coinfection

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are important global public health problems. Coinfection with HBV and HCV is not uncommon due to the shared route of parenteral transmission. The interaction between HBV and HCV in coinfected individuals is complex, and viral interference has been well described. Patients who are coinfected with HBV and HCV have faster rates of fibrosis progression, more severe liver disease, and are at markedly increased risk of developing hepatocellular carcinoma as compared to those with HBV or HCV monoinfection. Therefore, treatment of HBV-HCV coinfection is important, but it is a challenging and evolving field. Hepatitis A virus (HAV) superinfection is associated with a high risk of liver failure and death in patients with underlying chronic liver disease, and all individuals with HBV-HCV coinfection should receive the HAV vaccine.     

Meeting vaccination quality measures for hepatitis A and B virus in patients with chronic hepatitis C infection

Coinfection with hepatitis A virus (HAV) or hepatitis B virus (HBV) in patients with chronic hepatitis C virus (HCV) is associated with increased morbidity and mortality. The Center for Medicare and Medicaid Services has identified HAV and HBV vaccination as a priority area for quality measurement in HCV. It is unclear to what extent patients with HCV meet these recommendations. We used national data from the Department of Veterans Affairs HCV Clinical Case Registry to evaluate the prevalence and predictors of meeting the quality measure (QM) of receiving vaccination or documented immunity to HAV and HBV in patients with chronic HCV. We identified 88,456 patients who had overall vaccination rates of 21.9% and 20.7% for HBV and HAV, respectively. The QM rates were 57.0% and 45.5% for HBV and HAV, respectively. Patients who were nonwhite or who had elevated alanine aminotransferase levels, cirrhosis, or human immunodeficiency virus were more likely to meet the HBV QM. Factors related to HCV care were also determinants of meeting the HBV QM. These factors included receiving a specialist consult, genotype testing, or HCV treatment. Patients who were older, had psychosis, and had a higher comorbidity score were less likely to meet the HBV QM. With a few exceptions, similar variables were related to meeting the HAV QM. The incidence of superinfection with acute HBV and HAV was low, but it was significantly lower in patients who received vaccination than in those who did not. CONCLUSION: Quality measure rates for HAV and HBV are suboptimal for patients with chronic HCV. In addition, several patient-related factors and receiving HCV-related care are associated with a higher likelihood of meeting QMs.     

Consensus statement on the role of hepatitis A vaccination in patients with chronic liver disease

Hepatitis A virus (HAV) is a ubiquitous, easily transmitted virus that can cause severe hepatitis, particularly in the adult population. Improvements in sanitation and hygiene in the developing world have led to a decline in immunity against HAV. A growing number of adults are now susceptible to infection, with those who have not been vaccinated against hepatitis B virus (HBV) being at risk of dual infection and potentially more severe illness. The symposium, "The role of hepatitis vaccination in patients with chronic liver disease", provided the opportunity to develop a consensus statement. It was concluded that patients with non-viral chronic liver disease (CLD) and certain groups with HBV infection can develop more severe disease in the event of HAV infection. It was identified that patients with CLD should be targeted for hepatitis A vaccination as soon as CLD is diagnosed.     

Chronic hepatitis B reactivation following infliximab therapy in Crohn's disease patients: need for primary prophylaxis

BACKGROUND: There is little information about the effect of infliximab on the clinical course of liver disease in Crohn's disease patients with concomitant hepatitis B virus (HBV) infection. Theoretically, immunosuppression induced by infliximab will facilitate viral replication which could be followed by a flare or exacerbation of disease when therapy is discontinued. There are no specific recommendations on surveillance and treatment of HBV before infliximab infusion. Two cases of severe hepatic failure related to infliximab infusions have been described in patients with rheumatic diseases. PATIENTS AND METHODS: Hepatitis markers (C and B) and liver function tests were prospectively determined to 80 Crohn's disease patients requiring infliximab infusion in three hospitals in Spain. RESULTS: Three Crohn's disease patients with chronic HBV infection were identified. Two of the three patients with chronic HBV infection suffered severe reactivation of chronic hepatitis B after withdrawal of infliximab therapy and one died. A third patient, who was treated with lamivudine at the time of infliximab therapy, had no clinical or biochemical worsening of liver disease during or after therapy. From the remaining 80 patients, six received the hepatitis B vaccine. Three patients had antibodies to both hepatitis B surface antigen (anti-HBs) and hepatitis B core protein (anti-HBc) with normal aminotransferase levels, and one patient had positive anti-hepatitis C virus (HCV) antibodies, negative HCV RNA, and normal aminotransferase levels. Except for the patients with chronic HBV infection, no significant changes in hepatic function were detected. CONCLUSIONS: Patients with Crohn's disease who are candidates for infliximab therapy should be tested for hepatitis B serological markers before treatment and considered for prophylaxis of reactivation using antiviral therapy if positive.     

Does antiviral therapy for hepatitis B and C prevent hepatocellular carcinoma?

Approximately 75% to 80% of hepatocellular carcinomas (HCC) worldwide are attributed to chronic hepatitis B virus (HBV) and chronic hepatitis C virus (HCV) infection. Thus, effective prevention of HBV and HCV infection and progression from acute HBV and HCV infection to chronic hepatitis, cirrhosis and HCC might prevent as many as 450,000 deaths from HCC each year. The most effective approach to preventing HCC is to prevent HBV and HCV infection through vaccination. Indeed HBV vaccine is the first vaccine demonstrated to prevent cancers. However, a vaccine for HCV is not available and for persons who are chronically infected with HBV or HCV, antiviral therapy is the only option for preventing HCC. Direct evidence supporting a benefit of antiviral therapy on the prevention of HCC has been shown in a few randomized controlled trials. There is abundant evidence that antiviral therapy, in patients with long-term virological response, can improve liver histology, providing indirect support that antiviral therapy may prevent HCC by slowing progression of liver disease and possibly even reversing liver damage. Nevertheless, the risk of HCC remains in patients with chronic HBV or chronic HCV infection if treatment is initiated after cirrhosis is established. These data indicate that treatment might be of greater benefit if instituted earlier in the course of chronic hepatitis B or C. Safer, more effective, and more affordable antiviral therapies are needed for both hepatitis B and hepatitis C so more patients can benefit from treatment and more HCCs can be prevented.     

Multiple viral hepatitis in injection drug users and associated risk factors

BACKGROUND: While infections due to hepatitis B virus (HBV) and hepatitis C virus (HCV) have been well-studied in injection drug users (IDUs), hepatitis A virus (HAV) infection and coinfection with multiple hepatitis viruses have received less attention. METHODS: Hepatitis serology as well as sociodemographic and drug-related parameters were explored in patients (n = 1512) admitted for opiate detoxification. RESULTS: Antibodies to HAV were positive in 57.7%, to HBV in 53.0%, and to HCV in 75.0% of the sample. Lack of any hepatic marker was reported in 11.2%; one marker was positive in 24.7%; two markers were positive in 31.2%; and all markers were positive in 32.9%. In patients with one positive marker, 58.8% had had exposure to HCV, and 27% had exposure to HAV. In patients with two positive markers, 46.7% were HAV/HCV and 41.8% HBV/HCV antibody positive. Presence of HBV and HCV antibodies was associated with older age, longer duration of (i.v.) heroin use, and a higher number of rehabilitation treatment episodes (anova), current coconsumption of cocaine was associated with presence of antibodies to either HAV, HBV, and HCV. CONCLUSIONS: Coinfection with hepatic viruses is highly relevant in IDUs, although HAV does not necessarily share the same risk factors relevant for HBV or HCV transmission. The need for outreach vaccination programs is emphasized for HAV and HBV in the target population. Primary prevention should be implemented before initiation or at early stages of a drug career. Epidemiology and transmission of HAV in IDUs requires further research.     

Is Hepatitis A More Severe in Patients with Chronic Hepatitis B and Other Chronic Liver Diseases?

There are several published case series of acute hepatitis A, with coverage ranging from epidemics to case reports, that provide information regarding the clinical course and outcome of hepatitis A in patients with underlying chronic hepatitis B virus (HBV) infection (1–12). Only a few reports have addressed the outcome of hepatitis A in patients with other chronic liver diseases (2, 13). Some, but not all, of these reports suggest that hepatitis A superimposed on chronic hepatitis B or other chronic liver diseases is associated with higher peak laboratory abnormalities, more severe disease, including fulminant hepatic failure, and a higher case fatality rate. In addition, analysis of HBsAg titer and serum markers of HBV replication, including HBeAg, HBV DNA, and DNA polymerase, reveals suppression of HBV replication. With the availability of hepatitis A virus (HAV) vaccine in many countries and its imminent approval for use in the United States, the issue of whether or not patients with chronic liver diseases, including chronic HBV infection, should be a target group for vaccination to prevent hepatitis A warrants consideration. The purpose of this review is to analyze the published literature addressing the clinical course and outcome of acute hepatitis A in patients with chronic HBV infection and other chronic liver diseases to determine if hepatitis A is more severe in these patients.     

The cost-effectiveness of hepatitis A vaccination in patients with chronic hepatitis C

Infection with hepatitis A virus (HAV) occasionally leads to acute liver failure and has a higher fatality rate in patients with chronic hepatitis C virus (HCV). Vaccination of patients with HCV against HAV is effective and well tolerated. This study examines the cost-effectiveness of HAV vaccination in North American patients with chronic HCV. A decision analysis model was constructed to compare 3 HAV vaccination strategies in adult patients with chronic HCV over a period of 5 years: (1) vaccinate no patients (treat none); (2) vaccinate only susceptible (anti-HAV negative) patients (selective); or (3) vaccinate all patients without prior testing of immune status (universal). Probabilities and direct costs were estimated from hospital data and the literature. The cost per patient for the 3 vaccination strategies were: treat none, $2.00; selective, $56.00; and universal, $82.00. For every 1,000,000 patients with HCV vaccinated over a 5-year period, the selective strategy prevented 128 symptomatic cases of HAV, 3 liver transplantations, and 3 deaths owing directly to HAV compared with the treat none strategy. In addition, the selective strategy costs an additional $427,000 per patient with HAV prevented, and $23 million per HAV-related death averted, compared with the treat none strategy. The results were most sensitive to the incidence of HAV infection; vaccination increased costs if the annual rate of infection was less than 0.56% (baseline, 0.01%). Vaccination of North American patients with chronic HCV against HAV infection is not a cost-effective therapy.     

Prevalence of hepatitis A virus and hepatitis B virus immunity in patients with polymerase chain reaction-confirmed hepatitis C: implications for vaccination strategy

OBJECTIVES: Administration of vaccine for hepatitis A virus (HAV) and hepatitis B virus (HBV) is recommended for patients with chronic hepatitis C (CHC) because of the potential for increased severity of acute hepatitis superimposed on existing liver disease. The aim of this study is to determine the prevalence of antibodies directed against HAV and HBV in patients with CHC, analyze demographic and risk factors associated with this prevalence, and develop a cost-effective vaccination strategy. METHODS: We reviewed records from 1092 CHC patients. Demographics and information regarding risk factors were obtained by history and questionnaire administered to all patients. The costs of vaccination and antibody testing were determined, based on standard laboratory and clinic charges at our institution. HAV and HBV markers were correlated to race, age, and risk factors. RESULTS: Of the total population studied (n = 1092), 72% were African-Americans, 27% white, and 1% others. Of 671 CHC patients tested for anti-HAV IgG, 252 (38%) were positive. Of 743 CHC patients tested for HBV antibodies (anti-hepatitis B core IgG or anti-hepatitis B surface), 494 (67%) were positive. African-Americans are more likely to have antibodies to HAV and HBV (67% and 75%, respectively) compared to whites (27% and 20%). The prevalence of anti-HAV was 76% in patients >60 yr, 34% in the 40- to 60-yr-old age group, and 21% in patients <40 yr. The highest prevalence of HBV antibodies was found in patients between the ages of 40-60 yr. No HCV risk factors were associated with increased HAV risk. In CHC patients with HBV antibodies, however, illicit injection drug use was the predominant risk factor. CONCLUSIONS: The prevalence of anti-HAV in patients with CHC was found to be similar to that of the general population in the United States (33% according to recent Centers for Disease Control data), consistent with the hypothesis that the two infections do not share risk factors. Because the prevalence of HAV immunity is low in CHC patients <40 yr, empiric HAV vaccination is cost effective. If two doses of vaccine are to be given, however, antibody testing of all HCV patients is indicated. In the subset of patients >60 yr of age or who are African-American, where the prevalence of HAV exposure is considerably higher, it would be cost effective to check the antibody ($36.00), before vaccination ($97.00). The prevalence of HBV antibodies, however, is significantly increased in patients with CHC compared with the general population (5.3% per the Centers for Disease Control), likely as a result of exposure to similar parenteral risk factors. HBV antibody testing ($26.00 per test) should, therefore, be undertaken in all CHC patients who are hepatitis B surface antigen negative, as this approach is cost-effective compared to empiric HBV vaccination ($438.00 for a three injection course).     

Acute hepatitis A and acquired immunity to hepatitis A virus in hepatitis B virus (HBV) carriers and in HBV- or hepatitis C virus-related chronic liver diseases in Thailand

A number of studies have suggested that the clinical course of hepatitis A virus (HAV) infection is more severe in patients with chronic liver disease (CLD). A study was undertaken to determine the impact of acute HAV in asymptomatic hepatitis B surface antigen (HBsAg) carriers (n = 20) and patients with hepatitis B virus (HBV)-(n = 8) or hepatitis C virus (HCV)-related (n = 4) CLD. Disease progression was compared with that in 100 patients with isolated HAV infection. No patient with HAV infection alone developed complications, and all recovered fully. Fulminant or submassive hepatitis occurred in 55% of HBsAg carriers and 33% of patients with HBV- or HCV-related CLD. The mortality rate in HBsAg carriers (25%) was not significantly different from that in the patients with CLD (33%). The seroprevalence of anti-HAV immunoglobulin G in 820 individuals was also determined. Approximately 50% of the individuals had acquired HAV infection between the ages of 21 and 30 years. It was demonstrated that HAV infection may have a more severe clinical course in patients with underlying CLD, particularly among older individuals. Vaccination for such patients should be considered.     

Induced immunity against hepatitis B virus

Prevention of hepatitis B virus (HBV) infection with its consequent development of HBV chronic liver disease and hepatocellular carcinoma is a global mandatory goal. Fortunately, safe and effective HBV vaccines are currently available. Universal hepatitis B surface antigen HBV vaccination coverage is almost done. Growing knowledge based upon monitoring and surveillance of HBV vaccination programs has accumulated and the policy of booster vaccination has been evaluated. This review article provides an overview of the natural history of HBV infection, immune responses and the future of HBV infection. It also summarizes the updated sources, types and uses of HBV vaccines, whether in the preclinical phase or in the post-field vaccination.     

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.     

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.     

Susceptibility to hepatitis A virus infection among chronic liver disease patients and healthy blood donors in Thailand

Due to improvements in socio-economic and sanitation conditions, Thailand has undergone a change from hyperendemicity to intermediate endemicity for hepatitis A virus infection, leaving a large part of the adult population without immunity. At the same time, the country is still highly endemic for hepatitis B and especially in the northeast, hepatitis C virus infection both of which when acquired during infancy or early childhood exhibit a strong tendency to turn towards chronic liver disease, although in particular with hepatitis B virus the asymptomatic carrier state is also rather common. As no cross-immunity exists between any of these viruses, double or triple infections do occur, a situation where previously acquired immunity to HAV becomes crucial as double infections have been shown to take a more severe or even fatal course. In the present study, we investigated 820 HBV- and/or HCV-related chronic liver disease (CLD) patients and 195 blood donors, both groups divided by 10-year age intervals, for the prevalence of anti-HAV. The results showed the same age dependence of immunity for all groups tested as can be expected for an area of intermediate endemicity, in that approximately 50% of those between 21 and 30 years of age had acquired anti-HAV. These findings indicate the immune response to HAV infection not to be altered by chronic infection with either HBV or HCV. Hence, vaccination against HAV should be considered, particularly in anti-HAV-negative patients with CLD.