Vaccination against hepatitis B: the Italian strategy

Risk of parenterally transmitted hepatitis following exposure to invasive procedures in Italy: SEIEVA surveillance 2000-2021

BACKGROUND & AIMS

Surgical interventions and invasive diagnostic/therapeutic procedures are known routes of transmission of viral hepatitis. Using data from the Italian surveillance system for acute viral hepatitis (SEIEVA), the aim of this study was to investigate the association between specific types of invasive procedures and the risk of acute HBV and HCV infections.

METHODS

Data from SEIEVA (period 2000-2021) were used. The association between acute HBV and HCV infection and potential risk factors, i.e. surgical interventions and diagnostic/therapeutic procedures (given according to the ICD-9-CM classification), was investigated in comparison to age-matched hepatitis A cases, used as controls, by conditional multiple logistic regression analysis.

RESULTS

A total of 8,176 cases with acute HBV, 2,179 with acute HCV, and the respective age-matched controls with acute HAV infection were selected for the main analysis. Most of the procedures evaluated were associated with the risk of acquiring HBV or HCV. The strongest associations for HBV infection were: gynaecological surgery (odds ratio [OR] 5.19; 95% CI 1.12-24.05), otorhinolaryngological surgery (OR 3.78; 95% CI 1.76-8.09), and cardiac/thoracic surgery (OR 3.52; 95% CI 1.34-9.23); while for HCV infection, they were: neurosurgery (OR 11.88; 95% CI 2.40-58.85), otorhinolaryngological surgery (OR 11.54; 95% CI 2.55-52.24), and vascular surgery (OR 9.52; 95% CI 3.25-27.87). Hepatitis C was also strongly associated with ophthalmological surgery (OR 8.32; 95% CI 2.24-30.92). Biopsy and/or endoscopic procedures were significantly associated with both HCV (OR 3.84; 95% CI 2.47-5.95) and, to a lesser extent, HBV infection (OR 1.48; 95% CI 1.16-1.90).

CONCLUSIONS

Despite the progress made in recent years, invasive procedures still represent a significant risk factor for acquiring parenterally transmitted hepatitis viruses, thus explaining the still numerous and unexpected cases diagnosed among the elderly population in Italy. Our results underline the importance of observing universal precautions to control the iatrogenic transmission of hepatitis viruses.

IMPACT AND IMPLICATIONS

Cases of parenterally transmitted acute viral hepatitis in the elderly population, that are difficult to explain based on the most widely recognised risk factors, continue to be diagnosed in Italy. Based on the Italian SEIEVA surveillance of acute viral hepatitis data, this study highlights an increased risk of acquiring hepatitis B and C following exposure to invasive procedures, which might explain the observed cases in elderly individuals. Furthermore, this finding emphasises the need to observe universal precautions strictly, in healthcare settings, including in the case of minor surgical procedures.

Clinical features and comorbidity pattern of HCV infected migrants compared to native patients in care in Italy: A real-life evaluation of the PITER cohort

BACKGROUND

Direct-acting antivirals are highly effective for the treatment of hepatitis C virus (HCV) infection, regardless race/ethnicity. We aimed to evaluate demographic, virological and clinical data of HCV-infected migrants vs. natives consecutively enrolled in the PITER cohort.

METHODS

Migrants were defined by country of birth and nationality that was different from Italy. Mann-Whitney U test, Chi-squared test and multiple logistic regression were used.

RESULTS

Of 10,669 enrolled patients, 301 (2.8%) were migrants: median age 47 vs. 62 years, (p < 0.001), females 56.5% vs. 45.3%, (p < 0.001), HBsAg positivity 3.8% vs. 1.4%, (p < 0.05). Genotype 1b was prevalent in both groups, whereas genotype 4 was more prevalent in migrants (p < 0.05). Liver disease severity and sustained virologic response (SVR) were similar. A higher prevalence of comorbidities was reported for natives compared to migrants (p < 0.05). Liver disease progression cofactors (HBsAg, HIV coinfection, alcohol abuse, potential metabolic syndrome) were present in 39.1% and 47.1% (p > 0.05) of migrants and natives who eradicated HCV, respectively.

CONCLUSION

Compared to natives, HCV-infected migrants in care have different demographics, HCV genotypes, viral coinfections and comorbidities and similar disease severity, SVR and cofactors for disease progression after HCV eradication. A periodic clinical assessment after HCV eradication in Italians and migrants with cofactors for disease progression is warranted.

The hepatitis D virus in Italy. A vanishing infection, not yet a vanished disease

Introduction

Hepatitis D Virus (HDV) infection is vanishing in Italy. It is therefore believed that hepatitis D is no longer a medical problem in the domestic population of the country but remains of concern only in migrants from HDV-endemic areas.

Objectives

To report the clinical features and the medical impact of the residual domestic HDV infections in Italy.

Methods

From 2010 to 2019, one hundred ninety-three first-time patients with chronic HDV liver disease attended gastroenterology units in Torino and San Giovanni Rotondo (Apulia); 121 were native Italians and 72 were immigrants born abroad. For this study, we considered the 121 native Italians in order to determine their clinical features and the impact of HDV disease in liver transplant programs.

Results

At the last observation the median age of the 121 native Italians was 58 years. At the end of the follow-up, the median liver stiffness was 12.0 kPa (95% CI 11.2-17.4), 86 patients (71.1%) had a diagnosis of cirrhosis; 80 patients (66.1%) remained HDV viremic. The ratio of HDV to total HBsAg transplants varied from 38.5% (139/361) in 2000-2009 to 50.2% (130/259) in 2010-2019, indicating a disproportionate role of hepatitis D in liver transplants compared to the minor prevalence of HDV infections in the current scenario of HBsAg-positive liver disorders in Italy.

Conclusion

Though HDV is vanishing in Italy, a legacy of ageing native-Italian patients with advanced HDV liver disease still represents an important medical issue and maintains an impact on liver transplantation.

Usefulness of a Hepatitis B Surface Antigen-Based Model for the Prediction of Functional Cure in Patients with Chronic Hepatitis B Virus Infection Treated with Nucleos(t)ide Analogues: A Real-World Study

In patients with chronic hepatitis B (CHB) under long-term treatment with nucleso(t)ide analogues (NAs), the loss of hepatitis B surface antigen (HBsAg) is a rare event. A growing body of evidence supports the use of quantitative HBsAg for the prediction of functional cure, although these results are mainly derived from studies performed on Asian patients with hepatitis B e antigen (HBeAg)-positive CHB. Here, we investigated the clinical role of quantitative HBsAg in a real-life cohort of CHB patients under treatment with NAs in a tertiary care center from North-West Italy. A total of 101 CHB patients (HBeAg-negative, n = 86) undergoing NAs treatment were retrospectively enrolled. HBsAg was measured at baseline (T0), 6 months (T1), 12 months (T2) and at the last follow-up (FU). Median FU was 5.5 (3.2–8.3) years; at the end of FU, 11 patients lost the HBsAg (annual incidence rate = 1.8%). Baseline HBsAg levels were significantly different between patients with no HBsAg loss and those achieving a functional cure (3.46, 2.91–3.97 vs. 1.11, 0.45–1.98 Log IU/mL, p < 0.001). Similarly, the HBsAg decline (Δ) from T0 to T2 was significantly different between the two groups of patients (0.05, −0.04–0.13, vs. 0.38, 0.11–0.80 Log IU/mL, p = 0.002). By stratified cross-validation analysis, the combination of baseline HBsAg and ΔHBsAg T0–T2 showed an excellent accuracy for the prediction of HBsAg loss (C statistic = 0.966). These results corroborate the usefulness of quantitative HBsAg in Caucasian CHB patients treated with antivirals for the prediction of HBsAg seroclearance.

Are men who have sex with men in Europe protected from hepatitis B?

Hepatitis B vaccination is recommended for men who have sex with men (MSM) in many countries, but information on vaccine coverage is scarce. We studied hepatitis B vaccination programmes and coverage among MSM in Europe to guide prevention. From a large (N = 174 209) pan-European MSM survey (EMIS-2010), we used data on self-reported hepatitis B vaccination, age, education, settlement size and disclosure of the same-sex sexual orientation ('outness'). We excluded participants with a history of hepatitis B. In multilevel (participants, countries) logistic regression models, we calculated adjusted odds ratios (aOR) with 95% confidence intervals (95% CI). We analysed data of 163 987 MSM in 38 European countries: 38.3% were 'out' to all or almost all, 56.4% reported vaccination against hepatitis B and 65.5% lived in countries with free recommended hepatitis B vaccination for MSM. In the final model the odds for being vaccinated increased with outness ('out to all or almost all': aOR 1.76, 95% CI 1.70-1.83 vs. 'out to no one') and with living in countries, where hepatitis B vaccination was recommended and free-of-charge for MSM (aOR 2.21, 95% CI 1.47-3.32 vs. 'no or unclear recommendation'). To increase hepatitis B vaccination coverage among MSM, implementation of MSM-specific recommendations and improvement of the societal climate for MSM is needed.

Immunization against Hepatitis B Surface Antigen (HBsAg) in a Cohort of Nursing Students Two Decades after Vaccination: Surprising Feedback

Health-care students can be exposed to biological risks during university training. The persistence of long-term immunogenicity against hepatitis B virus (HBV) was analyzed in a cohort of nursing students two decades after primary vaccination. A total of 520 students were enrolled at the University of Palermo and were evaluated for levels of anti-HBsAg antibodies. The students were examined during the first year of their Degree Course and were checked two years later. All students with anti-HBsAg <10 mIU/mL during their first or third year were boosted within one month. The proportion of students that were vaccinated during adolescence showing anti-HBsAg ≥10 mIU/mL was higher than that observed in students who were vaccinated during infancy (69% versus 31.7%; p-value < 0.001). Receiving HBV vaccination at adolescence was significantly associated with a fourfold increased possibility of having anti-HBsAg titers ≥10 mIU/mL (adj-OR = 4.21, 95% CI: 2.43–7.30). Among the students who were checked at the third year and boosted after the first year (n = 279), those who were vaccinated during infancy showed a higher percentage of antibody titers <10 mIU/mL (20.3% versus 8.7% among vaccinated during adolescence; p < 0.01). This study confirms that HBV vaccination at adolescence might determine a higher long-term persistence of anti-HBsAg titers ≥10 mIU/mL and that anti-HBV booster could increase levels of anti-HBsAg over a relatively short period, especially in subjects who were vaccinated during infancy.

Prevalence, incidence and residual risk of transfusion-transmitted hepatitis B virus infection in Italy from 2009 to 2018

BACKGROUND

In Italy, the use of nucleic acid testing for hepatitis B virus (HBV) in donor screening has allowed the detection of infections in the window phase, as well as the presence of occult infections which could potentially be transmitted. The aim of this study was to analyse the trends of epidemiological data focused on HBV infection in blood donors and to estimate the residual risk of transmitting HBV from both the window phase and occult infection over a 10-year period in Italy.

MATERIALS AND METHODS

Data were obtained from the Italian Haemovigilance System which includes the results of screening tests for transfusion transmissible infections. During the period of this survey (2009-2018), the molecular methods used for HBV screening were transcription-mediated amplification and polymerase chain reaction tests. Prevalence and incidence were calculated. The residual risk was estimated by applying the incidence-window period model for acute cases and a more recently reported model for estimating the risk due to occult infections.

RESULTS

A total of 17,424,535 blood donors and 30,842,794 donations were tested for HBV. Altogether, 6,250 donors tested positive for HBV markers: 4,782 (175.6×10⁵) were first time donors and 1,468 (10.0×10⁵) were repeat donors. The prevalence of HBV markers in first time donors was 275.9×10⁵ in 2009, declining to 143.6×10⁵ in 2018. The incidence of new infections was 3.37×10⁵ in 2009 and 2.17×10⁵ in 2018. The overall residual risk for HBV amounted to 1 in 2,566,854 donations calculated as the sum of risks of both acute infections in the window period (1 in 5,835,306 donations) and occult infections (1 in 4,582,270 blood units).

DISCUSSION

In Italy, the residual risk of transfusing a blood unit infected with HBV, both from window phase and occult infections, is currently very low, amounting to levels that can be considered tolerable.

Low prevalence of hepatitis B and hepatitis C virus serum markers in a cohort of pregnant women from Southern Italy

BACKGROUND

Mother-to-child transmission is still considered a major factor in the spread of hepatitis viruses. Nevertheless, epidemiological data on hepatitis B virus (HBV) and hepatitis C virus (HCV) in reproductive-age women are limited even in areas like the South of Italy where both viruses had been widespread.

AIM

The aim of this study was to investigate the prevalence of HBV and HCV serum markers in a large cohort of pregnant women from Southern Italy.

METHODS

Data concerning 7558 pregnant women consecutively admitted to an Obstetric Division of a Sicilian University Hospital over a six-year period (January 2010-December 2015) were retrospectively collected from clinical notes.

RESULTS

Positivity for both HBV s-antigen (HBsAg) and antibodies to HCV (anti- HCV) was very low (0.5% and 0.2%, respectively). HBsAg prevalence was significantly higher in non-Italian than in Italian women (p<0.001). On the contrary, all the anti-HCV positive cases were of Italian origin. Age was not significantly different between positive and negative women.

CONCLUSION

These results confirm the dramatic decline of HBV and HCV prevalence that recently occurred in Southern Italy, and highlight the importance and cost-effectiveness of systematic HBV and HCV screening in childbearing age women in order to properly apply the available preventive measures and definitively eliminate the risk of vertical transmission for both viruses.

Persistence of immunity 18-19 years after vaccination against hepatitis B in 2 cohorts of vaccinees primed as infants or as adolescents in Italy

This study was aimed at assessing the anti-HBs persistence and immune memory 18-19 y after vaccination against hepatitis B in healthy individuals primed as infants or adolescents. We enrolled 405 teenagers (Group A) vaccinated as infants, and 409 young adults (Group B) vaccinated as adolescents. All vaccinees were tested for anti-HBs and anti-HBc antibodies; those found anti-HBc positive were further tested for HBsAg and HBV DNA. Eight individuals belonging to Group B were positive for anti-HBc alone, and were excluded from analysis. Individuals with anti-HBs concentration ≥ 10 mIU/ml were considered protected while those with anti-HBs concentration <10 mIU/ml were offered a booster dose and re-tested 2 weeks later. Overall, 67.9% individuals showed anti-HBs concentrations ≥ 10 mIU/ml (48.9% in Group A vs 87.0% in Group B, p < 0.001). The antibody geometric mean concentration (GMC) was higher in Group B than in Group A (102.5 mIU/ml vs 6.9 mIU/ml; p < 0.001). When boosted, 94.2% of vaccinees with anti-HBs <10 mIU/ml belonging to Group A and 94.7% to Group B showed an anamnestic response. Post-booster GMCs were similar in both groups (477.9 mIU/ml for Group A vs 710.0 mIU/ml for Group B, p = n.s.). Strong immunological memory persists for at least 18-19 y after immunization of infants or adolescents with a primary course of vaccination. Thus, booster doses are not needed at this time, but additional follow up is required to assess the long-life longevity of protection.

Hepatitis B virus infection in undocumented immigrants and refugees in Southern Italy: demographic, virological, and clinical features

Background

The data on hepatitis b virus (HBV) infection in immigrants population are scanty. The porpoise of this study was to define the demographic, virological, and clinical characteristics of subjects infected with HBV chronic infection in a cohort of immigrants living in Naples, Italy.

Methods

A screening for HBV infection was offered to 1,331 immigrants, of whom 1,212 (91%) (831 undocumented immigrants and 381 refugees) accepted and were screened for hepatitis B surface antigen (HBsAg) and anti-hepatitis B core antibody (HBc). Those found to be HBsAg positive were further investigated at third-level infectious disease units.

Results

Of the 1,212 immigrants screened, 116 (9.6%) were HBsAg positive, 490 (40.4%) were HBsAg negative/anti-HBc positive, and 606 (50%) were seronegative for both. Moreover, 21 (1.7%) were anti-human immunodeficiency virus positive and 45 (3.7%) were anti-hepatitis C virus positive. The logistic regression analysis showed that male sex (OR: 1.79; 95%CI: 1.28–2.51), Sub-Saharan African origin (OR: 6.18; 95%CI: 3.37–11.36), low level of schooling (OR: 0.96; 95%CI: 0.94–0.99), and minor parenteral risks for acquiring HBV infection (acupuncture, tattoo, piercing, or tribal practices, OR: 1.54; 95%CI: 1.1–2.16) were independently associated with ongoing or past HBV infection. Of the 116 HBsAg-positive immigrants, 90 (77.6%) completed their diagnostic itinerary at a third-level infectious disease unit: 29 (32.2%) were asymptomatic non-viremic HBsAg carriers, 43 (47.8%) were asymptomatic viremic carriers, 14 (15.6%) had chronic hepatitis, and four (4.4%) had liver cirrhosis, with superimposed hepatocellular carcinoma in two.

Conclusions

The data illustrate the demographic, clinical and virological characteristics of HBV infection in immigrants in Italy and indicate the need for Italian healthcare authorities to enhance their support for providing screening, HBV vaccination, treatment, and educational programs for this populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-016-0228-4) contains supplementary material, which is available to authorized users.

Hepatitis B virus, hepatitis C virus and human immunodeficiency virus infection in undocumented migrants and refugees in southern Italy, January 2012 to June 2013

Screening of undocumented migrants or refugees for hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections has been offered free of charge and free from bureaucratic procedures since 2012 at four primary-level clinical centres in Naples and Caserta, Italy. Of 926 undocumented migrants and refugees visiting one of the primary-level clinical centres from January 2012 to June 2013, 882 (95%) were screened for hepatitis B surface antigen (HBsAg), total hepatitis B core antibody (anti-HBc) and antibodies against HCV and HIV. Of the 882 individuals enrolled, 78 (9%) were HBsAg positive, 35 (4%) anti-HCV positive and 11 (1%) anti-HIV positive (single infections); seven (1%) had more than one infection (three were HBsAg positive). Of the 801 HBsAg-negative patients, 373 (47%) were anti-HBc positive. The HBsAg-positivity rate was high (14%; 62/444) in individuals from sub-Saharan Africa and intermediate in those from eastern Europe (6%; 12/198), northern Africa (2%; 2/80) and Bangladesh, India, Pakistan and Sri Lanka (the 'India-Pakistan area') (3%; 4/126). Anti-HCV was detected in 9/126 (7%) individuals originating from the India-Pakistan area, in 12/198 (6%) from eastern Europe, in 17/444 (4%) from sub-Saharan and in 2/80 (2%) from northern Africa. The HBV, HCV and HIV infections in the undocumented migrants and refugees screened serve as a reminder to the Italian healthcare authorities to carry out extensive screening and educational programmes for these populations.

Acute Hepatitis B After the Implementation of Universal Vaccination in Italy: Results From 22 Years of Surveillance (1993-2014)

BACKGROUND

Hepatitis B vaccination has proven to be very safe and highly effective. This study assessed the proportion of successfully vaccinated individuals among cases with acute hepatitis B, the proportion of preventable cases if individuals were vaccinated as recommended, and the reasons for failures.

METHODS

We analyzed data reported to the Italian Surveillance System for Acute Viral Hepatitis from 1993 to 2014.

RESULTS

A total of 362 of 11 311 (3.2%) cases with acute hepatitis B were vaccinated. Of the 277 cases for whom immunization data were available, 50 (18%) received a complete vaccination course according to the correct schedule and before exposure to hepatitis B virus. Molecular characterization of 17 of these cases showed that 6 were infected with S-gene mutants. Among the 10 949 unvaccinated cases, 213 (1.9%) escaped mandatory vaccination and 2821 (25.8%) were not vaccinated despite being at increased risk of infection. Among the latter, the most common risk factors were cohabitation with hepatitis B surface antigen (HBsAg) carriers, intravenous drug use, and homosexual/bisexual practices. Thirty-seven percent of the unvaccinated households with HBsAg carriers were aware of their risk. Lack of trust in the vaccination, negative attitude, and inaccurate beliefs followed by lack of or poor communication and low perceived severity of the disease were the most frequent reasons for vaccine hesitancy.

CONCLUSIONS

Development of acute disease in successfully vaccinated individuals is a rare event. Further efforts are needed to enhance the vaccine coverage rate in individuals at increased risk of infection.

The long-term immunogenicity of recombinant hepatitis B virus (HBV) vaccine: contribution of universal HBV vaccination in Italy

Background

Universal hepatitis B virus (HBV) vaccination of newborn babies was introduced in Italy in 1991 and was extended to 12-years-old children for the first 12 years of application so as to cover in a dozen years the Italian population aged 0-24 years. The aim of this study was to identify factors associated with long-term immunogenicity against HBV 17 years after primary vaccination in students attending medical schools in Naples, Italy.

Methods

1,704 students attending the school of medicine, schools of the healthcare professions, or postgraduate medical schools of the Second University of Naples, Italy, from September 2012 to December 2013 were enrolled in this study. Of these, 588 had been vaccinated against HBV in infancy and 1,116 when 12 years old. Multivariate logistic regression analysis was used to identify factors associated with the level of long-term immunogenicity.

Results

All vaccinated subjects were HBsAg/anti-HBc negative: 270 (15.8%) had an anti-HBs titer between 1 and 9 IU/L, 987 (57.9%) between 10 and 400 IU/L, and 447 (26.3%) over 400 IU/L. When compared with the latter two subgroups, those with anti-HBs titers lower than 10 IU/L were younger (24 ± 5.2 years vs. 26 ± 4.9 years, p < 0.000), more frequently students attending a healthcare school (59% vs. 47%, p < 0.001), and more frequently had been vaccinated in infancy (50% vs. 31.5%, p < 0.0001). Multivariate logistic regression identified age at vaccination as the only factor independently associated with an anti-HBs titer <10 IU/L (OR: 2.43; C.I. 95%: 1.57–3.76, p = 0.001).

Conclusions

Universal HBV vaccination in Italy has been more effective in generating a prolonged protective response in subjects vaccinated at adolescence than in infancy. Students with a low anti-HBs titer should be considered for a booster dose because most will be exposed to the risk of acquiring HBV for decades.

Prevention of hepatocellular carcinoma: beyond hepatitis B vaccination

Chronic hepatitis B (CHB) infection is the major cause of hepatocellular carcinoma (HCC), accounting for approximately 50% of the underlying etiologies. We reviewed the primary, secondary, and tertiary measures for the prevention of hepatitis B virus (HBV)-related HCC. The most effective method for preventing HBV-related HCC is vaccination. Universal hepatitis B vaccination has been shown to reduce the rates of HBV infection and HCC significantly. Once chronic HBV infection is established, antiviral treatment using interferon or nucleos(t)ide analogs is used to prevent disease progression to cirrhosis, HCC, or both. Studies have found viral replication indicated by HBV DNA level to be a strong risk factor for development of HCC. Additionally, periodic surveillance using ultrasonography and serum α-fetoprotein for earlier detection of HCC is also important so that curative treatments with survival benefit can be possible. Finally, adjuvant antiviral treatment using interferon or nucleos(t)ide analogs is used to prevent tumor recurrence after curative resection. Adjuvant interferon treatment prevented early recurrence, not late recurrence, probably due to its antiangiogenetic and antiproliferative effects. Adjuvant nucleos(t)ide analogs demonstrated promising results for preventing late recurrence, probably due to effective suppression of viral replication. Further investigations are required to establish the optimal preventive plans for HBV-related HCC.

Epidemiology of acute and chronic hepatitis B and delta over the last 5 decades in Italy

The spread of hepatitis B virus (HBV) infection has gradually decreased in Italy in the last 5 decades as shown by the steady reduction in the incidence rates of acute hepatitis B, from 10/100000 inhabitants in 1984 to 0.85/100000 in 2012, and by the reduced prevalence of hepatitis B surface antigen (HBsAg)-positive cases among chronic hepatitis patients with different etiologies, from 60% in 1975 to about 10% in 2001. The prevalence of HBsAg chronic carriers in the general population also decreased from nearly 3% in the 1980s to 1% in 2010. Linked to HBV by its characteristics of defective virus, the hepatitis delta virus (HDV) has shown a similar epidemiological impact on the Italian population over time. The incidence of acute HDV infection decreased from 3.2/100000 inhabitants in 1987 to 0.8/100000 in 2010 and the prevalence of HDV infection in HBsAg chronic carriers decreased from 24% in 1990 to 8.5% in 2006. Before the beneficial effects of HBV mass vaccination introduced in 1991, the decreased endemicity of HBV and HDV infection in Italy paralleled the improvement in screening blood donations, the higher standard of living and impressive reduction in the birth rate associated with a marked reduction in the family size. A further contribution to the decline in HBV and HDV infections most probably came from the media campaigns to prevent the spread of human immunodeficiency virus infection by focusing the attention of the general population on the same routes of transmission of viral infections such as unsafe sexual intercourse and parenteral exposures of different kinds.

Hepatitis B immunity in teenagers vaccinated as infants: an Italian 17-year follow-up study

We assessed the persistence of hepatitis B surface antigen antibody (anti-HBs) and immune memory in a cohort of 571 teenagers vaccinated against hepatitis B as infants, 17 years earlier. Vaccinees were followed-up in 2003 and in 2010 (i.e. 10 years and 17 years after primary vaccination, respectively). When tested in 2003, 199 vaccinees (group A) had anti-HBs <10 mIU/mL and were boosted, 372 (group B) were not boosted because they had anti-HBs ≥10 mIU/mL (n = 344) or refused booster (n = 28) despite anti-HBs <10 mIU/mL. In 2010, 72.9% (416/571) of participants had anti-HBs ≥10 mIU/mL (67.3% in group A vs. 75.8% in group B; p 0.03). The geometric mean concentrations (GMCs) were similar in both groups. Between 2003 and 2010, anti-HBs concentrations in previously boosted individuals markedly declined with GMC dropping from 486 to 27.7 mIU/mL (p <0.001). Fifteen vaccinees showed a marked increase of antibody, possibly due to natural booster. In 2010, 96 individuals (37 of group A and 59 of group B) with anti-HBs <10 mIU/mL were boosted; all vaccinees of the former group and all but two of the latter had an anamnestic response. Post-booster GMC was higher in group B (895.6 vs. 492.2 mIU/mL; p 0.039). This finding shows that the immune memory for HBsAg persists beyond the time at which anti-HBs disappears, conferring long-term protection.

Sero-epidemiology of hepatitis B markers in the population of Tuscany, Central Italy, 20 years after the implementation of universal vaccination

Italy was one of the first industrialized countries to introduce a program of universal vaccination against hepatitis B in 1991. Twenty years later we verified the impact of universal immunisation on the epidemiology of hepatitis B infection by analyzing the prevalence of specific viral markers (anti-HBs, anti-HBc and HBsAg). The ELISA tests were performed on residual blood samples collected by 0.05% of the resident population aged 1-50 years in Tuscany (Italy). About 63% of subjects aged < 30 years were anti-HBs positive compared to about 25% in older subjects, without differences between genders. About 22% of subjects over 40 years were anti-HBc-positive compared to 5% in the younger age groups. The number of HBsAg-positive subjects was almost 10 fold higher in the unvaccinated age groups than in the cohorts involved in the universal vaccination program. The results of our study show the persisting high anti-HBs reactivity in vaccinated cohorts, while HBV markers related to natural exposure or persistent infection remain remarkably higher in older age groups. This sero-epidemiological study supports with prevalence data the downward incidence trend of acute hepatitis B highlighted by epidemiological surveillance systems, and corroborates the forecast for elimination of hepatitis B in Italy in a few decades.

Viral hepatitis: global goals for vaccination

In countries where hepatitis A is highly endemic, exposure to hepatitis A virus (HAV) is almost universal before the age of 10 years, and large-scale immunization efforts are not required. In contrast, in areas of intermediate endemicity or in transition from high to intermediate endemicity, where transmission occurs primarily from person to person in the general community (often with periodic outbreaks), control of hepatitis A may be achieved through widespread vaccination programmes. Hepatitis B virus (HBV) is one of the world's most widespread infectious agents and the cause of millions of infections each year. Between 500,000 and 700,000 people die each year from chronic infection-related cirrhosis, hepatocellular carcinoma (HCC) or from acute hepatitis B. Hepatitis B vaccine provides protection against infection and its complications including liver cirrhosis and HCC. It is therefore, the first vaccine against a cancer, the first vaccine protecting from a sexually transmitted infection, and the first vaccine against a chronic disease ever licensed. Control and significant reduction in incidence of new HBV infections as well as hepatocellular carcinoma has repeatedly been reported in countries in East Asia (i.e. Taiwan) and Africa (i.e. The Gambia). Two experimental vaccines against hepatitis E have been developed; one of them has been recently licensed but is not yet widely available. Attempts to develop a hepatitis C vaccine were so far unsuccessful.

Twenty years of universal vaccination against hepatitis B in Italy: achievements and challenges

Viral hepatitis B is a vaccine-preventable disease. Vaccination has proved to be safe and highly effective in reducing the incidence, the carrier rate and HBV-related mortality on a global scale. In Italy, universal vaccination against hepatitis B started in 1991 in infants as well as in adolescents, providing an outstanding record of safety and effectiveness. Within a few years, over 95% coverage was consistently reported. Today, some 17 million people are immune against hepatitis B and their immunity has been shown to be long-lasting. At present, no booster is required in healthy vaccinated people to sustain protection. Surveillance data from Italy have shown a clear overall decline in hepatitis B among successfully vaccinated individuals. Furthermore, a generation of children and young people (at present cohorts ranging from 0 to 32 years) is emerging with practically no markers of HBV infection. Italy’s vaccination programme has resulted in substantial progress towards the prevention and control of hepatitis B. The vaccination programme must continue. Maintaining mandatory vaccination of infants and increasing HBV vaccination coverage in high-risk groups, including households of HBsAg carriers as well as immigrants, remain a priority for the future.

Epidemiology of hepatitis D virus (HDV) infection in an urban area of northern Italy

OBJECTIVES

The introduction of vaccination against hepatitis B initially reduced the number of HBV (hepatitis B virus) and HDV (hepatitis delta virus) infections, but the decreasing trend of HDV infection seems to have stopped. The aim of this study was to assess the prevalence of HDV infection in the general population living in the catchment area of Legnano Hospital in northern Italy.

METHODS

Of the 22,758 subjects tested in 2007-2008, the 488 who were HBsAg (hepatitis B surface antigen)-positive [including 107 (21.9%) of non-Italian origin] were subsequently tested for anti-HDV antibodies.

RESULTS

Of the 488 subjects who tested positive for HBsAg, 24 (4.9%) were anti-HDV positive, all aged between 30 and 60 years. The difference in prevalence between males (7.1%) and females (1.9%) was statistically significant (p < 0.05), but not that between Italian (5.0%) and non-Italian patients (4.7%). The differences in anti-HDV seropositivity between the patients with acute (0%) and chronic infections (6.3%), and between the incident (2.5%) and prevalent cases (7.4%), were not statistically significant, but there was a significant difference (p < 0.01) between those with asymptomatic (2.1%) and clinically symptomatic infections (10.3%). Intravenous drug abuse was the main source of infection.

CONCLUSIONS

In the catchment area of our hospital, the prevalence of HDV infection does not seem to be due to patients of non-Italian origin, but to Italian patients who are not vaccinated against HBV and who survived the HDV epidemic of the 1970s and 1980s. Nevertheless, the increase in the number of immigrants from non-EU countries in recent years is soon likely to lead to a change in the epidemiology of HDV.

Lack of association of RAD51 genetic variations with hepatitis B virus clearance and occurrence of hepatocellular carcinoma in a Korean population

The RecA homolog, E. coli (S. cerevisiae) (RAD51) may modulate hepatitis B virus (HBV) infection by maintaining genome integrity and mediating homologous DNA repairs. In this study, 16 sequence variations were detected by resequencing all exons, the exon-intron boundary, and promoter regions of the human RAD51 gene in DNA samples of 24 unrelated individuals. To investigate the association of common variations in the RAD51 locus with HBV infection and hepatocellular carcinoma (HCC) occurrence, six common polymorphisms were genotyped in a total of 1,103 Korean HBV cohort, composed of 433 spontaneously recovered patients as controls and 670 chronic carriers of HBV, who were stratified further into 327 cirrhosis/chronic hepatitis patients and 343 patients with HCC infected with HBV. Logistic analyses revealed no significant association of RAD51 polymorphisms and haplotypes with HBV clearance and HCC occurrence (P > 0.05). Furthermore, with age of infection as an important factor in disease progression to HCC, results from the Cox proportional hazards analysis showed no significant associations between any of the tested RAD51 variants and the age of onset of HCC (P > 0.05), suggesting that genetic polymorphisms of RAD51 may not play an important role in clearance of HBV and disease progression to HCC. Although studies in other populations are needed to confirm these findings, this preliminary data may contribute to the current knowledge on the pathogenesis of hepatitis.

The worldwide impact of vaccination on the control and protection of viral hepatitis B

Viral hepatitis B is a leading cause of acute and chronic liver disease worldwide, including cirrhosis and hepatocellular carcinoma. Vaccination is the most effective measure for controlling and preventing hepatitis B and its severe long-term sequelae. According to the World Health Organization (WHO), by the end of 2008 177 countries had introduced hepatitis B vaccination into their national routine neonatal, infant and/or adolescent immunisation programmes, and Italy was one of the first countries to implement a universal strategy of hepatitis B vaccination. The implementation of such vaccination programmes has globally resulted in a marked decrease in disease burden, in the carrier rate and in hepatitis B-related morbidity and mortality. Despite this success, work remains to be done to fully achieve the WHO goal of control of hepatitis B and HBV-related diseases on a global scale.

Long-term antibody persistence and immune memory to hepatitis B virus in adult celiac patients vaccinated as adolescents

Aim of this study was to investigate the anti-HBs antibody persistence and immune memory to hepatitis B virus in adult celiacs vaccinated as adolescents and the effect of a booster administration in non-protected individuals. Eleven years after primary vaccination, the proportion of vaccinees with titres ≥ 10 mIU/ml and antibody geometric mean concentrations (GMCs) were lower among celiac patients than among controls (68.6% vs 91.7%, p<0.01; GMCs 29.38 mIU/ml vs 250.6 mIU/ml, p<0.001). Participants with anti-HBs below 10 mIU/ml received a booster dose and were retested 2 weeks later to assess the anamnestic response. Post-booster anti-HBs levels were still <10 mIU/ml in 71.4% celiacs and 25% controls (p<0.01). Our findings indicate that the prevalence of seroprotective levels of anti-HBs detected eleven years after primary immunization as well as the frequency of response to a booster dose of vaccine are lower in celiac patients compared to healthy controls.

Chronic viral hepatitis as a public health issue in the world

This article will focus on the impact caused by chronic viral hepatitis B and C globally and will discuss public health measures that have to be implemented in order to prevent and control these diseases. Chronic viral hepatitis is a major global public health problem, an important cause of morbidity and mortality from sequelae which include chronic hepatitis, cirrhosis and primary liver cancer. Being a 'silent' disease, the contribution of chronic hepatitis to global morbidity and mortality is generally underestimated. Hepatitis B and C prevention and control should seek to reduce both the incidence of new infections and the risk of chronic liver disease. A comprehensive public health prevention programme should include the prevention and detection of HBV and HCV infections, the diagnosis and control of viral hepatitis related chronic liver disease, conducting surveillance and monitoring the effectiveness of prevention activities, and setting up a research agenda.

The global impact of vaccination against hepatitis B: a historical overview

Hepatitis B virus (HBV) infection is a world wide public health problem of major concern. HBV infection may lead to chronic liver disease, including cirrhosis and hepatocellular carcinoma (HCC). Vaccination is the most effective measure to control and prevent hepatitis B and its long-term serious sequelae on global scale, both in terms of cost-effectiveness and benefit-cost ratios. According to the WHO recommendations, universal vaccination has been currently implemented in 168 countries world wide with an outstanding record of safety and efficacy. The effective implementation of such programmes of vaccination has resulted in a substantial decrease in disease burden, in the carrier rate and in hepatitis B-related morbidity and mortality. A future challenge is to overcome the social and economic hurdles which still hamper the introduction of hepatitis B vaccination on a global scale.

Impact of hepatitis B vaccination in a highly endemic area of south Italy and long-term duration of anti-HBs antibody in two cohorts of vaccinated individuals

The aims of this study were to evaluate the impact of hepatitis B vaccination on the changing pattern of HBV infection in a former hyperendemic area (Afragola, South Italy), and to assess the long-term persistence of anti-HBs in two cohorts of individuals vaccinated as infants 18 and 23 years ago. Our data shows a significant decline in the prevalence of hepatitis B virus (HBV) markers in the general population from 1978 to 2006 (HBsAg: 13.4% versus 0.91%; anti-HBc: 66.9% versus 7.6%; p<0.001). Data from two cohorts of vaccinees provides further evidence regarding the long-term persistence of vaccine-induced anti-HBs. Data here reported indicates that the implementation of vaccination had a great impact in the control and prevention of hepatitis B in Italy.

Long-term immunogenicity of hepatitis B vaccination in a cohort of Italian healthy adolescents

In 1992, 620 adolescents were vaccinated against hepatitis B. Anti-HBs concentrations were measured in 480 (77.4%) adolescents 1 month after completion of the primary course of vaccination. To assess the persistence of anti-HBs, 347 and 228 of such vaccinees were retested for anti-HBs in 1999 and for anti-HBs and anti-HBc in 2003. More than 10 years after vaccination, individuals with anti-HBs >or=10 mIU/ml were considered protected while those with antibody <10 mIU/ml were given a booster dose and retested 2 weeks later. Check performed in 2003 showed that 208/228 (91.2%) vaccinees retained protective concentrations of anti-HBs. All vaccinees were anti-HBc negative. 11 of the 12 (91.7%) individuals who were given a booster dose of vaccine showed a vigorous anamnestic response while the remaining one showed a weak response (10.6 mIU/ml). These data suggests that hepatitis B vaccination can confer long-term immunity and that immunological memory can outlast the loss of antibody. Hence, the use of routine booster doses of vaccine does not appear necessary to maintain long-term protection in successfully vaccinated immunocompetent individuals.

Changing patterns of hepatitis B infection in Italy and NAT testing for improving the safety of blood supply

In Italy, as in most industrialized countries, the burden of hepatitis B has progressively declined in recent decades as a consequence of general improvements in hygiene and standard of living, the introduction of several public health measures, refinement in blood screening and the implementation of specific vaccination programmes. Universal hepatitis B vaccination for all infants and adolescents as well as individuals at increased risk has resulted in considerable progress towards prevention and control of HBV infection. The residual risk of transmitting blood-borne viruses through transfusion is currently very low. Nucleic acid testing can shorten the window period and, consequently, further reduce the risk of viral transmission. Blood donor screening for HCV by NAT was initiated in Italy in 2001 and became mandatory in June 2002. NAT for HIV is currently mandatory in four regions, not mandatory but almost universally performed in another thirteen regions, and not yet introduced in the remaining four regions. NAT for HBV is currently mandatory in four regions and under evaluation in the remaining. NAT for HBV may be a useful tool in detecting acute viral infections in the window phase as well as the occult infections. Its efficacy in improving the safety of blood supply is expected to be higher in countries with intermediate/high endemicity, where anti-HBc antibody screening cannot be routinely performed. There is agreement that, at present, the implementation of HBV DNA testing will not allow for discontinuation of screening for HBsAg.

Long-term immunogenicity of hepatitis B vaccination and policy for booster: an Italian multicentre study

BACKGROUND

Universal anti-hepatitis-B vaccination of infants and adolescents was implemented in Italy in 1991. We undertook a multicentre study in previously vaccinated individuals to assess the duration of immunity and need for booster, over 10 years after vaccination.

METHODS

In 1212 children and 446 Italian Air Force recruits vaccinated as infants and adolescents, respectively, we measured the concentrations of antibodies to hepatitis-B surface antigen (anti-HBs) and the presence of antibodies to hepatitis-B core antigen (anti-HBc) at enrollment; postimmunisation values were not available. Individuals positive for anti-HBc were tested for hepatitis B surface antigen (HBsAg) and hepatitis B viral DNA. Individuals with anti-HBs concentrations at 10 IU/L or more were regarded as protected; those with antibody less than 10 IU/L were given a booster dose and retested 2 weeks later. Individuals showing postbooster anti-HBs concentrations of less than 10 IU/L were offered two additional vaccine doses and retested 1 month after the third dose.

FINDINGS

Protective anti-HBs concentrations were retained in 779 (64%, 95% CI 61.6-67) children and 398 (89%, 86.4-92.1) recruits. We recorded antibody amounts of less than 10 IU/L in 433 children (36%, 33-38.4) and 48 (11%, 7.9-13.6) recruits. One child and four recruits were positive for anti-HBc, but negative for HBsAg and hepatitis B viral DNA. Antibody concentrations were higher in recruits than in children (geometric mean titre 234.8 IU/L vs 32.1 IU/L, p=0.0001). 332 (97%) of 342 children and 46 (96%) of 48 recruits who received a booster showed an anamnestic response, whereas ten (3%) children and two (4%) recruits remained negative for anti-HBs or had antibody concentrations of less than 10 IU/L. Prebooster and postbooster antibody titres were strongly correlated with each other in both groups. All individuals given two additional vaccine doses (eight children and two recruits) showed anti-HBs amounts of more than 10 IU/L at 1 month after vaccination.

INTERPRETATION

Strong immunological memory persists more than 10 years after immunisation of infants and adolescents with a primary course of vaccination. Booster doses of vaccine do not seem necessary to ensure long-term protection.

Hepatitis B in Italy: where we are ten years after the introduction of mass vaccination

In Italy, a program of vaccination against hepatitis B targeted at the immunisation of persons at high risk began in 1983. In 1991, vaccination became mandatory for all newborns and adolescents. Since then, the vaccine has been given to more than 10 million children, with an outstanding record of safety and efficacy. The coverage rate is globally around 94%, with differences between the Northern and Southern regions, with the latter having the lower acceptance rate. According to the National Surveillance System (SEIEVA), the incidence of acute hepatitis B per 10(5) inhabitants declined from 5.4 in 1990 to 2 in 2000. The reduction was even greater among 15-24-year-old individuals, where the incidence rate per 10(5) decreased from 17.3 to 2 in the same period. In parallel with the decline of hepatitis B, hepatitis delta has also declined significantly. Catch-up immunisation of unvaccinated adolescents, as well as an effort to improve the vaccination coverage rate in high-risk groups, are required to ameliorate the efficacy of the vaccination campaign. Routine administration of booster doses of vaccine is not considered necessary to sustain immunity in immunocompetent persons.

Update on hepatitis B vaccination in Italy 10 years after its implementation

Since the beginning of the Italian program of immunization against hepatitis B, vaccine has been given to more than 9 million children, with an outstanding record of safety and efficacy. The coverage rate is globally around 94%, with differences between Northern and Southern regions, the latter having the lower acceptance rate. According to the National Surveillance System (SEIEVA), the incidence of acute hepatitis B per10(5) inhabitants declined from 5.4 in 1990 to 2.9 in 1998. The reduction was even greater among 15-24-year-old individuals, where the incidence rate per 10(5) decreased from 17.3 to 4.2 in the same period. In parallel with the decline of hepatitis B, Delta hepatitis has also dropped significantly. We expect that by the year 2003 (12 years after the beginning of the program) this vaccination strategy will have led to the protection of all Italians aged 0-24 years, who are those at the higher risk for acquiring hepatitis B virus (HBV) and for developing the chronic carrier state.

Hepatitis B vaccine: current issues

OBJECTIVE

To review two main issues concerning the hepatitis B vaccine: (1) the management of unresponsive subjects and (2) the need for routine booster doses.

DATA SOURCES

Pertinent literature identified via MEDLINE (1980-1996) search as well as references cited in published articles.

DATA SYNTHESIS

The optimal procedure for management of subjects unresponsive to hepatitis B vaccine has not been well established. Most unresponsive subjects are not absolute nonresponders, since most of them can develop protective concentrations of antibodies to hepatitis B surface antigen (anti-HBsAg) after hepatitis B revaccination, consisting of a fourth or a fifth dose or a new complete course of immunization. In subjects who do not respond to the hepatitis B vaccine after four or more injections, the benefits of the combination of cytokines (e.g., interferon-alfa, interleukin-2 [aldesleukin]) and vaccine have not been clearly shown. There are two main opinions regarding the need for routine booster doses. Experts from the US, claiming long-term protection from immunologic memory, suggest delaying booster doses for at least a decade after vaccination in subjects with normal immune status. Furthermore, postvaccination antibody testing should be restricted only to high-risk subjects. Once a vaccinated subject has responded satisfactorily, further antibody tests are unnecessary. Only hemodialysis patients should be tested annually for adequate antibody concentrations and the booster dose administered when concentrations decline to less than 10 IU/L. Experts from Europe suggest that vaccine-induced antibody responses should be assessed in all subjects and booster doses administered at intervals, with the theory being that protection correlates with the presence of antibody. However, indications about appropriate timing for booster doses and target titers of anti-HBsAg remain controversial.

CONCLUSIONS

It is possible to obtain seroconversion in nonresponders by using variations in vaccination strategies (i.e., > 3 doses, double amounts of HBsAg). Adjuvants such as interferon-alfa or aldesleukin are of limited use. The opinions of American experts regarding routine booster doses, as expressed by the statement of the Immunization Practices Advisory Committee, seem to be well defined and helpful to clinicians trying to resolve controversies for individual patients. The opinions of the European experts are not unanimous and are sometimes impractical. A consensus conference is needed.

Strategy for vaccination against hepatitis B in areas with high endemicity: focus on Korea

Hepatitis B vaccination strategies may vary from country to country depending on hepatitis B virus (HBV) endemicity, predominant modes of infection, age of infection, and health care resources. In areas with high endemicity like Korea, transmission of virus from carrier mothers to infants during the perinatal period, and from other horizontal sources to infants and children, account for most cases of HBV infection. The consequences of HBV infection at an early age are serious, as more than 70% remain chronic carriers of the virus. These chronic carriers are the principal source of infection for other susceptible people, and are themselves at high risk of developing other serious diseases, such as chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Theoretically, therefore, routine infant immunisation supplemented with prenatal screening of pregnant women for HBsAg or HBeAg and mass immunisation of children is the appropriate strategy for control of hepatitis B in these countries. To prevent primary liver cancer associated with HBV infection, however, immunisation of adults at high risk would also be prudent. Mandatory vaccination of all neonates is recommended in highly endemic areas, together with hepatitis B immune globulin in babies born to HBsAg carrier mothers.

Implementation in Italy of a universal vaccination programme against hepatitis B

Italy was the first industrialized country to introduce mass vaccination against hepatitis B. Following the collection of epidemiological data on age-specific incidence rates of infection, a law was issued in 1991 which established mandatory immunization of neonates and 12-year-old adolescents. This strategy will lead to the protection of all subjects aged 0-24 years within 12 years and to the elimination of circulation of hepatitis B virus (HBV) in a few decades. The first data on compliance with vaccination, both in infants and in adolescents, indicate the success of the programme, which was helped by good vaccination delivery services and awareness of the risks of hepatitis B both by physicians and the public. A multi-centre study on protective antibody level and kinetics over time is in progress. Preliminary results show an excellent response to vaccination. High-risk strategies will continue by actively offering HBV vaccination free of charge to all those exposed to infection via occupation or life-style. The Italian policy of universal vaccination against HBV can therefore be regarded as a model for the introduction of mass immunization into other countries.

Cloning and growth-regulated expression of the gene encoding the hepatitis B virus middle surface antigen in Yarrowia lipolytica

Expression of the gene encoding the hepatitis B virus middle surface antigen (pre-HBsAg) in the yeast Yarrowia lipolytica has been studied. The preS2-HBsAg gene was expressed from the alkaline extracellular protease-encoding gene (XPR2) promoter. In the fusion construct, the membrane-spanning 'a' domain of preS2-HBsAg has been replaced by the leader peptide and the proI region of the alkaline protease, thus eliminating the epitope responsible for the immune escape mechanism. Expression has been found to be growth-stage dependent with the highest protein accumulation during the stationary phase, accounting for around 2.35% of the total soluble intracellular proteins. The produced protein was assembled into Dane particles and was immunogenic in mice. The expression vector was found to be stable for at least 100 generations under non-selective conditions.