Hepatitis B carriers in Sweden--effects of immigration

Long-term follow-up of HBsAg-positive patients in Germany

BACKGROUND

Little is known about the prognosis and complications of chronic hepatitis B in countries with low disease prevalence including Germany.

MATERIALS AND METHODS

This retrospective/prospective study analyzes the course of 608 HBsAg-positive patients between 2002 and 2012 in Germany. The follow-up duration was 5.2±2.9 years (mean±SD) and the age of the patients was 40.4±13.8 years. Of the total cohort, 59.9% were men; 34.9% had been born in Germany, 30.4% in Turkey, and 34.7% in other countries.

RESULTS

In 78.3% of women, diagnosis was made during pregnancy screening, which is the only reinforced screening procedure in Germany. During follow-up, 21 patients died, five had a LTX, and 20 developed a hepatocellular carcinoma. Of the total cohort, 15% developed at least one severe liver-associated complication. By multivariate analysis, prognosis was associated with high age and cirrhosis, but not with sex, HBV-DNA, alanine aminotransferase, and ethnic origin. Of the 608 patients, 211 (34.7%) had at least one antiviral therapy. Of the 178 patients who were treated with nucleot(s)ides at the last visit 88.8% had an HBV-DNA less than 20 IU/ml.

CONCLUSION

Today, in Germany, hepatitis B is a disease of migrants. The present data show that mandatory screening is effective and needs to include more high-risk groups. Mortality and complications including hepatocellular carcinoma are associated primarily with cirrhosis and age, but not with HBeAg status or viral load probably because modern therapies considerably reduce viral replication in almost all patients. The prognosis is exclusively determined by the risk for hepatocellular carcinoma.

Hepatitis B virus transmission in pre-adolescent schoolchildren in four multi-ethnic areas of England

The aim of this study was to estimate the amount of childhood hepatitis B virus transmission in children born in the UK, a very low-prevalence country, that is preventable only by universal hepatitis B immunization of infants. Oral fluid specimens were collected from schoolchildren aged 7-11 years in four inner city multi-ethnic areas and tested for the presence of antibody to hepatitis B core antigen (anti-HBc). Those found positive or indeterminate were followed up with testing on serum to confirm their hepatitis B status. The overall prevalence of anti-HBc in children was low [0.26%, 95% confidence interval (CI) 0.14-0.44]. The estimated average annual incidence of hepatitis B was estimated to be 29.26/100 000 children (95% CI 16.00-49.08). The total incidence that is preventable only by a universal infant immunization programme in the UK was estimated to be between 5.00 and 12.49/100 000. The study demonstrates that the extent of horizontal childhood hepatitis B virus transmission is low in children born in the UK and suggests that schools in the UK are an uncommon setting for the transmission of the virus. Targeted hepatitis B testing and immunization of migrants from intermediate- and high-prevalence countries is likely to be a more effective measure to reduce childhood transmission than a universal infant immunization programme.

Liver and gallbladder cancer in immigrants to Sweden

BACKGROUND

The changes of cancer incidence upon immigration can be used as an estimator of environmental influence on cancer risk. We studied site-specific liver and biliary cancers in first-generation immigrants to Sweden with an aim to search for aetiological clues and to find evidence for indigenous incidence rates.

MATERIAL AND METHODS

We used the nation-wide Swedish Family-Cancer Database to calculate standardised incidence ratios (SIRs) in immigrants compared to native Swedes.

RESULTS

A total of 1428 cancers were identified in immigrants whose median ages (years) at immigration were 27 for men and 26 for women and whose median diagnostic ages were 64 and 66, respectively. The highest SIRs of 6.7 for primary liver cancer were observed for men from East Asia and sub-Saharan Africa. Increased SIRs were recorded for male immigrants from previous Yugoslavia (1.78), Southern Europe (2.91), Turkey (2.15) and Asian Arab countries (2.89). For gallbladder cancer, only women from the Indian subcontinent (3.84) and Chile (2.34) had increased risk while some Northern European immigrants showed decreased risks.

CONCLUSIONS

Primary liver cancer was increased in immigrants from endemic regions of hepatitis B virus infection but also from large regions lacking cancer incidence data, North Africa, Asian Arab countries, Turkey and previous Yugoslavia; these are probably intermediary risk regions for this infection. The consideration of these regions as risk areas would justify active diagnostic and vaccination programs. The increase in gallbladder cancer in Chileans and Indians suggests that some persistent damage was inflicted before emigration, characterisation of which will be a challenge for aetiological studies.

Seroepidemiology of hepatitis B virus infection in pregnant women in Catalonia (Spain)

BACKGROUND

In recent years there has been a substantial reduction in hepatitis B incidence as a result of routine vaccination of preadolescents and the selective vaccination of high risk groups and newborns of HBsAg+ mothers.

OBJECTIVES

To determine the prevalence of hepatitis B virus infection markers and of serologic markers of hepatitis B vaccination in a representative sample of pregnant women in Catalonia.

STUDY DESIGN

A representative sample was obtained by random cluster sampling (hospitals with maternity units) stratified by provinces. Anti-HBc, anti-HBs and HBsAg were determined using an ELISA test (Behring, Marburg, Germany). The crude and adjusted odds ratios for the sociodemographic variables analyzed were also calculated.

RESULTS

The global prevalence of carriers of HBsAg+ was 0.1% (95% CI 0.0-0.3), that of hepatitis B infection (anti-HBc+) was 5% (95% CI 3.9-6.1) and that of serologic markers of vaccination (anti-HBs+ and anti-HBc-) was 16.4% (95% CI 14.5-18.2) The prevalence of infection increased with age from 3.0% (15-19 years age group) to 14.8% (40-44 years age group). The prevalence of anti-HBc+ was higher in women born in Asia (27.6%) and Africa (18.8%) than in those born in Spain (3.7%), Europe (3.3%) and America (4.6%), with the differences being statistically significant.

CONCLUSIONS

The results of this study confirm the change in the pattern of endemicity of hepatitis B infection in pregnant women in Catalonia after the introduction of vaccination programmes. They also confirm the increasingly important role played by immigration in the epidemiology of hepatitis B.

High impact of migration on the prevalence of chronic hepatitis B in the Netherlands

OBJECTIVES

A representative serosurveillance study (1995) resulted in an estimate of 0.2% for the HBsAg prevalence in the Netherlands. Some risk groups, especially migrants, were not well represented in the study, which probably led to an underestimation of the true HBsAg prevalence. The aim of this study was to calculate an adjusted HBsAg prevalence estimate for the total Dutch population including these risk groups.

METHODS

According to their country of origin first-generation migrants (FGM) were classified into groups with low, intermediate and high prevalence using data from the WHO and Statistics Netherlands. The number of chronic HBsAg carriers in different age and population groups was estimated based on studies about age-specific prevalence in different countries. The number of carriers in the indigenous population was estimated using the serosurveillance study. A combination of these estimates led to an estimate of the total prevalence rate in the Netherlands.

RESULTS

Nearly 10% of the Dutch population are FGM. Of these, about 18% were born in low-endemic, 71% in middle-endemic and 11% in high-endemic countries. The overall prevalence of HBsAg in FGM is estimated to be at 3.77%. Combining these results with the results of the serosurveillance study the HBsAg prevalence in the Dutch population is estimated to be between 0.32 and 0.51%, and when including injecting drug users and mentally handicapped persons the prevalence rates are 0.36 and 0.55%, respectively.

CONCLUSION

Our results show the high importance of targeting migrants and their close contacts adequately in screening programmes, vaccination and treatment for chronic hepatitis B.

Estimates and projections of hepatitis B-related hepatocellular carcinoma in Australia among people born in Asia-Pacific countries

BACKGROUND AND AIM

Australia has increasing immigration from hepatitis B virus (HBV) endemic countries of the Asia-Pacific region (APR). This study estimates immigration-related chronic HBV cases, chronic HBV prevalence, and HBV-related hepatocellular carcinoma (HCC) from 1960 to 2005 and projects HBV-related HCC to 2025 in Australia among people born in the APR.

METHODS

The populations of APR origin for the period 1960-2005 were derived from Australian census data. HBV prevalence from population-based sero surveys in the APR countries was used to estimate new chronic HBV cases (immigrant arrivals per year with chronic HBV). Age-specific incidence rates of HCC derived from a Taiwanese population-based study were used to estimate and project HBV-related HCC.

RESULTS

Chronic HBV cases among APR-born population increased rapidly from the late 1970s reaching a peak of 4182 in 1990. Chronic HBV prevalence increased to >53 000 in 2005. Estimates of HBV-related HCC increased linearly from one in 1960 to 140 in 2005, with a projected increase to 250 in 2025. Universal HBV vaccination programs in countries of origin had limited impact on projected HBV-related HCC to 2025.

CONCLUSION

The burden of chronic HBV including HBV-related HCC among APR-born Australians has increased over the past three decades and is projected to increase further during the next two decades.

Chronic disease mortality associated with infectious agents: a comparative cohort study of migrants from the Former Soviet Union in Israel and Germany

BACKGROUND

Prevalence of infectious diseases in migrant populations has been addressed in numerous studies. However, information is sparse on their mortality due to chronic diseases that are aetiologically associated with an infectious agent. This study investigates mortality related to infectious diseases with a specific focus on cancers of possibly infectious origin in voluntary migrants from the Former Soviet Union residing in Israel and in Germany.

METHODS

Both groups of migrants arrived from the Former Soviet Union in their destination countries between 1990 and 2001. Population-based data on migrants in Israel were obtained from the Israel Central Bureau of Statistics. Data for migrants in Germany were obtained from a representative sample of all migrants from the Former Soviet Union in Germany. Cause of death information was available until 2003 for the Israeli cohort and until 2005 for the German cohort. Standardized mortality ratios were calculated relative to the destination country for selected causes of death for which infectious agents may be causally involved. Multivariate Poisson regression was applied to assess differences in mortality by length of residence in the host country.

RESULTS

Both in Israel and in Germany these migrants have lower overall mortality than the population in their destination countries. However, they have significantly elevated mortality from viral hepatitis and from stomach and liver cancer when compared to the destination populations. Regression analysis shows that in Israel stomach cancer mortality is significantly higher among migrants at shorter durations of residence when compared to durations of more than nine years.

CONCLUSION

Higher mortality from cancers associated with infection and from viral hepatitis among migrants from the Former Soviet Union might result from higher prevalence of infections which were acquired in earlier years of life. The results highlight new challenges posed by diseases of infectious origin in migrants and call attention to the link between communicable and non-communicable diseases.

Should hepatitis B vaccination be introduced into childhood immunisation programmes in northern Europe?

Infection with hepatitis B causes between 500,000 and 1.2 million deaths per year worldwide, and is the leading cause of liver cancer. Over 12 years ago, WHO recommended that universal childhood hepatitis B vaccination be implemented globally. Despite this, Denmark, Finland, Iceland, Ireland, the Netherlands, Norway, Sweden, and the UK have yet to implement such a policy and instead currently adopt an "at-risk" strategy. Although all eight countries are classed as having low endemicity, factors such as increased travel and integration of immigrant communities are increasing the number of at-risk individuals in these countries. Considering the difficulty in identifying all at-risk individuals, and the lack of effectiveness of at-risk vaccination on reducing the overall incidence of hepatitis B, we recommend that these countries reassess their hepatitis B prevention strategies. Universal vaccination against hepatitis B is the only way to eliminate the major public-health impact of this disease.

Molecular epidemiology and variation of hepatitis B in recent immigrant families to Australia

Natural variation in hepatitis B virus (HBV) was studied in asymptomatic carriers originating from countries of high endemicity. HBV DNA was detected by dot blot and/or polymerase chain reaction (PCR) in 34 of the 184 members of 22 new immigrant families who agreed to be tested after one of their children had been found to have current or past hepatitis B in a school survey. PCR products from both the S and distal-X pre-C regions were sequenced. One vaccinated child had the classical "escape" mutation at amino acid position 126 in the S-gene and two other children and two adults had other substitutions at amino acid positions 133, 120, 165, and 159. Mutations were more frequent in the distal-X pre-C region and included two pre-C mutants and 13 other amino acid substitutions. The strains originating in the various countries were placed in almost identical groups by phylogenetic analysis using each amplicon, and determination of subtype by antigenic analysis gave the same result as sequencing. The S-data allowed recognition of three dominant strains within genotype B, while the distal-X pre-C data provided better discrimination between family groups. No change was found when the sequence of samples obtained for the study was compared with those collected from 14 of the children two years earlier. There was some evidence of horizontal spread in addition to vertical transmission. Reports of mutations of HBV in patients with severe or unusual clinical features should be interpreted with caution until the prevalence of the mutant in asymptomatic carriers has been determined.