Risk of hepatitis B for travelers: is vaccination for all travelers really necessary?

Clinicoepidemiological characteristics of viral hepatitis in migrants and travellers of the +Redivi network

BACKGROUND

Continuous growth of mobile populations has influenced the global epidemiology of infectious diseases, including chronic and acute viral hepatitis.

METHOD

A prospective observational multicentre study was performed in a Spanish network of imported infections. Viral hepatitis cases from January 2009 to September 2017 were included.

RESULTS

Of 14,546 records, 723 (4.97%) had imported viral hepatitis, including 48 (6.64%) acute cases and 675 (93.36%) chronic cases. Of the 48 acute cases, 31 were travellers and immigrants returning from visiting friends or relatives (VFR), while 19 (61%) were acute Hepatitis A or Hepatitis B. Only 18.2% of VFR immigrants and 35% of travellers received pre-travel advice. Acute hepatitis was more frequent in VFR immigrants (AOR 2.59, CI95% 1.20-5.60) and travellers (AOR 2.83, CI95% 1.46-5.50) than immigrants. Of the 675 Chronic cases, 570 were immigrants, and 439 (77%) had chronic Hepatitis B. Chronic hepatitis was more frequent in immigrants (AOR 20.22, CI95% 11.64-35.13) and VFR immigrants (AOR 11.12, CI95% 6.20-19.94) than travellers.

CONCLUSIONS

Chronic viral hepatitis was typical of immigrants, acute viral hepatitis was common among travellers, and VFR immigrants had mixed risk. Improving pre-travel consultation and screening of immigrants may contribute to preventing new cases of viral hepatitis and avoiding community transmission.

Hepatitis B vaccination coverage among adults aged ≥18 years traveling to a country of high or intermediate endemicity, United States, 2015

BACKGROUND

Persons from the United States who travel to developing countries are at substantial risk for hepatitis B virus (HBV) infection. Hepatitis B vaccine has been recommended for adults at increased risk for infection, including travelers to high or intermediate hepatitis B endemic countries.

PURPOSE

To assess hepatitis B vaccination coverage among adults ≥18 years traveling to a country of high or intermediate endemicity from the United States.

METHODS

Data from the 2015 National Health Interview Survey (NHIS) were analyzed to determine hepatitis B vaccination coverage (≥1 dose) and series completion (≥3 doses) among persons aged ≥18 years who reported traveling to a country of high or intermediate hepatitis B endemicity. Multivariable logistic regression and predictive marginal analyses were conducted to identify factors independently associated with hepatitis B vaccination.

RESULTS

In 2015, hepatitis B vaccination coverage (≥1 dose) among adults aged ≥18 years who reported traveling to high or intermediate hepatitis B endemic countries was 38.6%, significantly higher compared with 25.9% among non-travelers. Series completion (≥3 doses) was 31.7% and 21.2%, respectively (P < 0.05). On multivariable analysis among all respondents, travel status was significantly associated with hepatitis B vaccination coverage and series completion. Other characteristics independently associated with vaccination (≥1 dose, and ≥3 doses) among travelers included age, race/ethnicity, educational level, duration of US residence, number of physician contacts in the past year, status of ever being tested for HIV, and healthcare personnel status.

CONCLUSIONS

Although travel to a country of high or intermediate hepatitis B endemicity was associated with higher likelihood of hepatitis B vaccination, hepatitis B vaccination coverage was low among adult travelers to these areas. Healthcare providers should ask their patients about travel plans and recommend and offer travel related vaccinations to their patients or refer them to alternate sites for vaccination.

Hepatitis B vaccination coverage among adults aged ≥ 18 years traveling to a country of high or intermediate endemicity, United States, 2015

BACKGROUND

Persons from the United States who travel to developing countries are at substantial risk for hepatitis B virus (HBV) infection. Hepatitis B vaccine has been recommended for adults at increased risk for infection, including travelers to high or intermediate hepatitis B endemic countries.

PURPOSE

To assess hepatitis B vaccination coverage among adults ≥ 18 years traveling to a country of high or intermediate endemicity from the United States.

METHODS

Data from the 2015 National Health Interview Survey (NHIS) were analyzed to determine hepatitis B vaccination coverage (≥1 dose) and series completion (≥3 doses) among persons aged ≥ 18 years who reported traveling to a country of high or intermediate hepatitis B endemicity. Multivariable logistic regression and predictive marginal analyses were conducted to identify factors independently associated with hepatitis B vaccination.

RESULTS

In 2015, hepatitis B vaccination coverage (≥1 dose) among adults aged ≥ 18 years who reported traveling to high or intermediate hepatitis B endemic countries was 38.6%, significantly higher compared with 25.9% among non-travelers. Series completion (≥3 doses) was 31.7% and 21.2%, respectively (P < 0.05). On multivariable analysis among all respondents, travel status was significantly associated with hepatitis B vaccination coverage and series completion. Other characteristics independently associated with vaccination (≥1 dose, and ≥ 3 doses) among travelers included age, race/ethnicity, educational level, duration of U.S. residence, number of physician contacts in the past year, status of ever being tested for HIV, and healthcare personnel status.

CONCLUSIONS

Although travel to a country of high or intermediate hepatitis B endemicity was associated with higher likelihood of hepatitis B vaccination, hepatitis B vaccination coverage was low among adult travelers to these areas. Healthcare providers should ask their patients about travel plans and recommend and offer travel related vaccinations to their patients or refer them to alternate sites for vaccination.

Vaccine-preventable travel health risks: what is the evidence--what are the gaps?

BACKGROUND

Existing travel health guidelines are based on a variety of data with underpinning evidence ranging from high-quality randomized controlled trials to best estimates from expert opinion. For strategic guidance and to set overall priorities, data about average risk are useful. The World Health Organization (WHO) plans to base future editions of "International Travel and Health" on its new "Handbook for Guideline Development."

METHODS

Based on a systematic search in PubMed, the existing evidence and quality of data on vaccine-preventable disease (VPD) risks in travelers was examined and essentials of vaccine efficacy were briefly reviewed. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework was used to evaluate the quality of the data.

RESULTS

Moderate-quality data to determine the risk of VPD exist on those that are frequently imported, whereas in most others the level of confidence with existing data is low or very low.

CONCLUSIONS

In order for the WHO to produce graded risk statements in the updated version of "International Travel and Health," major investment of time plus additional high-quality, generalizable risk data are needed.

Risk factors and pre-travel healthcare of international travellers attending a Dutch travel clinic: a cross-sectional analysis

BACKGROUND

The number of international travellers is currently estimated to exceed one billion annually. To address travel related health risks and facilitate risk reduction strategies, detailed knowledge of travellers' characteristics is important.

METHOD

In this cross-sectional study, data of a 20% sample of travellers visiting the Academic Medical Center (AMC) travel clinic Amsterdam from July 2011 to July 2012 was collected. Itineraries and protection versus exposure rates of preventable infectious diseases were mapped and reported according to STROBE guidelines.

RESULTS

1749 travellers were included. South-Eastern Asia, South-America and West-Africa were most frequently visited. 26.2% of the population had pre-existing medical conditions (often cardiovascular). Young and VFR travellers had a longer median travel time (28 and 30 days) compared to the overall population (21 days). Young adult travellers were relatively often vaccinated against hepatitis B (43.9% vs. 20.5%, p < .001) and rabies (16.6% vs. 4.3%, p < .001). VFRs were less often vaccinated against hepatitis B (11.6% vs. 30.6%, p < .001) and rabies (1.3% vs. 9.0%, p .012) compared to non-VFR travellers.

CONCLUSIONS

Pre-travel guidelines were well adhered to. Young adult travellers had high-risk itineraries but were adequately protected. Improvement of hepatitis B and rabies protection would be desirable, specifically for VFRs.

Acute hepatitis in israeli travelers

BACKGROUND

Acute hepatitis is a well-described cause of morbidity and sporadic mortality in travelers. Data regarding the epidemiology of hepatitis in travelers are lacking. The aim of this study is to describe the epidemiology of acute viral hepatitis among travelers returning from tropical countries, with particular attention to enterically transmitted hepatitis.

METHODS

This study is a prospective observational study of ill-returned travelers who presented at two travel medicine clinics in Israel between the years 1997 and 2012. Data of patients with acute hepatitis were summarized. Only travelers were included, immigrants and foreign workers were excluded.

RESULTS

Among 4,970 Israeli travelers who were seen during this period, 49 (1%) were diagnosed with acute hepatitis. Among them, hepatitis E virus (HEV) was the etiology in 19 (39%) cases and hepatitis A virus (HAV) was the etiology in 13 (27%) cases, demonstrating that 65% of all cases were due to enterically transmitted hepatitis. Acquiring acute hepatitis B (two cases) or acute hepatitis C (one case) was uncommon (6.1%). In 27% of the cases, no diagnosis was determined. Fifty-five percent of cases were imported from the Indian subcontinent, with a predominance of HEV infection (84%). A significant male predominance was seen in all groups regardless of etiology. Pre-travel consultation was documented in only 7% of those with vaccine preventable hepatitis (hepatitis A & B) compared to 89% in those with hepatitis E.

CONCLUSIONS

Enterically transmitted hepatitis is the main causes of viral hepatitis among travelers. HEV is an emerging disease and has become the most common hepatitis among Israeli travelers. Although an efficacious vaccine has been developed, no licensed HEV vaccine is yet available. Although hepatitis A vaccine is highly efficacious, safe, and easily available, there is a stable number of HAV cases.

Hepatitis B and C infection in international travelers

BACKGROUND

Hepatitis B and C virus (HBV and HCV) cause significant morbidity and mortality worldwide. With the rise in international travel over the last three decades, many travelers are at risk of HBV and HCV infection.

METHODS

This review focuses on the epidemiology of HBV and HCV in international travelers, the modes of transmission, and the prevention of infection in travelers.

RESULTS

The risk of HBV and HCV infection varies widely and depends on the prevalence of the destination country, the duration of travel, and the activities undertaken while abroad. Travelers commonly undertake high-risk activities that place them at risk of both HBV and HCV infection. Poor uptake of preventative health measures and poor adherence to health recommendations are also common. The monthly incidence of HBV infection for long-term travelers to endemic countries ranges from 25 to 420 per 100,000 travelers. HBV infection can be prevented through timely vaccination of travelers. HBV vaccination is safe and efficacious with protective levels of antibodies achieved in >90% of recipients. Information regarding the risk of HCV acquisition is scarce and until recently was limited to case reports following medical interventions.

CONCLUSIONS

This review demonstrates international travelers are at risk of HBV and HCV infection and provides evidence-based information enabling health practitioners to provide more appropriate pre-travel advice. HBV vaccination should be considered in all travelers to countries with a moderate to high HBV prevalence (HBsAg ≥ 2%) and the risk and benefits discussed with the individuals in consultation with the health practitioner. There is no duration of travel without risk of HBV infection. However, it is apparent that those travelers with a longer duration of travel are at greatest risk of HBV infection (ie, expatriates). Travelers should also receive advice regarding the modes of transmission and the activities that place them at risk of both HBV and HCV infection.

Incidence of acute hepatitis B in different ethnic groups in a low-endemic country, 1992-2009: increased risk in second generation migrants

BACKGROUND

The Netherlands is a low-incidence country for acute hepatitis B (HBV) infection (1.2/100,000 in 2010), where it is typically acquired in adulthood through injecting drug use or homosexual exposure. Recently, the number of heterosexually acquired acute infections in the Netherlands has increased. Ethnicity may be a risk factor. We describe trends in the incidence of acute HBV among heterosexual adults in ethnic groups in Amsterdam from 1992 to 2009 and discuss future control of HBV in the Netherlands.

METHODS

We studied all cases of acute HBV acquired in heterosexuals aged ≥15 years in the Amsterdam region (1992-2009, n=238) by ethnic group. Incidence rates were estimated as the average number of cases per 100,000 per year. Using Poisson regression, we calculated univariable and multivariable incidence rate ratios (IRR) by ethnic group over calendar year, by age and gender.

RESULTS

The incidence in first generation migrants from HBV-endemic countries (FGM) was 4.1/100,000 showing no trend over time. Since 1999, incidence in Dutch-born cases in Amsterdam has increased by 13% annually from 0.2/100,000 in 1999 to 2.1/100,000 in 2009 (annual IRR 1.13, 95% CI:1.0-1.22). From 2004 to 2009, the incidence in native Dutch/Western in Amsterdam was 1.6/100,000 (reference for IRR), in FGM was 4.3/100,000 (IRR of 2.7, 95% CI:1.8-4.2) and in Dutch-born second generation migrants (SGM) was 3.7/100,000 (IRR:2.4, 95% CI:1.2-4.7).

CONCLUSION

Incidence of acute hepatitis B in Amsterdam in FGM and SGM is higher than in the native Dutch population. Low-endemic countries with migrant populations from HBV-endemic areas should consider offering screening and vaccination to both FGM and SGM.

Predictors for the uptake of recommended vaccinations in Mecca travelers who visited the Public Health Service Amsterdam for mandatory meningitis vaccination

BACKGROUND

Hajj, the pilgrimage to Mecca, is one of the obligatory religious duties of Islam. The travel clinic of the Public Health Service (PHS) Amsterdam administers vaccinations, including the required meningitis ACYW135 vaccine, and provides travelers with individual recommendations for all their travels.

METHODS

We extracted all data from the PHS database pertaining to Muslims who visited the clinic before travel to Mecca. From 2001 to 2009, the characteristics are described and trends are analyzed retrospectively. Acceptance of dTP vaccine was used as a proxy for acceptance of recommended vaccinations. For the years 2007 to 2009, predictive factors for the acceptance of advised vaccinations are analyzed.

RESULTS

From 2001 to 2009, significantly more women and people older than 50 years of age traveled to Mecca. Since 2007, only 527 of 2,156 (24%) of those who were advised to take vaccines accepted the recommendation. Independent factors for acceptance were being female, of younger age, and being less healthy. Specifically, Mecca travelers with heart disorders and with liver or gastrointestinal disorders accepted recommended vaccinations more often than those without.

CONCLUSIONS

Only a quarter of Mecca travelers who visit the travel clinic for their mandatory meningitis vaccination also take other, recommended, vaccinations. To improve the acceptance rate, Islamic organizations that inform Mecca travelers in preparation for their travel should be supplied with up-to-date advice, not only about the requirements but also about recommended vaccinations and health precautions.