The risk of acquiring hepatitis A and B among travelers in selected Eastern and Southern Europe and non-European Mediterranean countries: review and consensus statement on hepatitis A and B vaccination

Travelers' Attitudes, Behaviors, and Practices on the Prevention of Infectious Diseases: A Study for Non-European Destinations

BACKGROUND

The aim of this study was to improve our comprehension of the attitudes, behaviors, and practices related to the health risks of travel to non-European destinations.

METHODS

This cross-sectional study utilized an online questionnaire disseminated through social networks.

RESULTS

About 79% of the respondents reported that they informed themselves or would inform themselves about travel-related health risks before departure. The most used sources of information were the Internet (52%) and health professionals (42%). Older age groups were positively associated with seeking pretravel health information (OR = 2.44, CI 95%: 1.18-5.01, in the age group 25-34 years and OR = 14.6, CI 95%: 1.77-119.50, in subjects over 65 years). Travelers visiting friends and relatives (VFRs) were less likely to seek health information (OR = 0.49; CI 95%: 0.26-0.95). About 13.9% of participants had doubts about the practice of vaccination. Those who sought information on social media had a higher probability of refusing vaccination (OR = 3.24; CI 95%: 1.02-10.19).

CONCLUSIONS

The data demonstrate that VFRs and the younger population are less informed about travel risks compared with other travelers. This study also revealed the importance that digital information assumes for travelers. Therefore, decisive efforts should be made to ensure that travelers can find correct and reliable information on the Web, particularly on social media.

Adherence to hepatitis A travel health guidelines: A cross-sectional seroprevalence study in Dutch travelling families - The Dutch travel Vaccination Study (DiVeST)

BACKGROUND

This Dutch travel Vaccination Study (DiVeST) aimed to study adherence or compliance to Dutch travel health guidelines in travelling families and to identify risk groups to provide better advice and protection for international travellers.

METHODS

Between 2016 and 2018, family members who travelled to Eastern Europe or outside Europe during the preceding year were recruited via Dutch secondary schools. The vaccination status of the travellers was assessed using questionnaires and vaccination records and hepatitis A virus antibody concentrations in dried blood spot (DBS) eluates. Subgroups of travellers with lower adherence to guidelines were identified.

RESULTS

Of the 246 travellers that participated in this study, 155 (63%) travelled to destinations for which the HAV vaccination was recommended. Of these 155 travellers, 56 (36%) said they visited a pre-travel clinic, and 64 of them (41%) showed a valid HAV vaccination in their vaccination records. Of the 145 travellers with available DBS eluates, anti-HAV antibodies were detected in 98 (68%) of them.

CONCLUSIONS

We found that adherence to travel health guidelines, in terms of HAV vaccination, was suboptimal. According to our results, specific attention should be paid to children, persons visiting friends and relatives and those who travel relatively short distances.

Hepatitis A immunity and region-of-origin in a Swiss prison

Purpose - The environmental and demographic characteristics of closed institutions, particularly prisons, precipitate morbidity during hepatitis A virus (HAV) outbreaks. Given the high prevalence of chronic liver disease and other risk factors in the prison setting, the purpose of this paper is to examine HAV-immunity and its associated factors in this population. Design/methodology/approach - The cross-sectional study was conducted in 2009: a serology screening for HAV IgG was carried out among 116 inmates in Switzerland's largest pre-trial prison. Other participant characteristics were collected through a structured face-to-face questionnaire with a physician. Findings - In terms of significant demographics, Africa (53.5 percent) and the Balkans/Eastern Europe (36.2 percent) were the main regions of origin; a minority of inmates were from Western Europe (6.9 percent), Latin America (2.6 percent) or Asia (0.9 percent). The authors identified hepatitis A antibody-negative serology (lack of immunity) in five out of 116 prisoners (4.3 percent, 95 percent CI 1.4-9.7). Among participants of European origin alone, five out of 50 inmates were hepatitis A antibody-negative (10 percent, 95 percent CI 3.3-21.8), whereas the 66 inmates from other all continents were hepatitis A antibody-positive (immune) (p=0.026). Originality/value - In this prison population composed of mostly African migrants, hepatitis A immunity was high. This reaffirms that region of origin is highly associated with childhood immunity against HAV. HAV vaccination should take into account a patient's area of origin and his/her risk factors for systemic complications, if ever infected. This targeted strategy would offer herd immunity, and seek out the most vulnerable individuals who are potentially at risk of new exposure in this precarious setting.

Redefining priorities towards graded travel-related infectious disease research

Our knowledge of the health problems and infections encountered by international travellers has evolved considerably in the past decades. The growth of global networks such as the GeoSentinel Surveillance network, TropNet Europe, EuroTravNet and networks based in North America have provided valuable information on the frequency of a wide array of travel-related diseases and accidents, including details on the destination of travel and trends over time. The information gained from these network studies has provided important data for the practice of travel medicine and in some instances for the development of practice guidelines. However, network data due to a lack of denominators usually cannot serve as a basis for a GRADE approach to guideline development. Although epidemiological network studies will continue to serve an important role in travel medicine we encourage an additional strong focus towards translational scientific research questions and towards the broader use of novel techniques to obtain more accurate epidemiological analyses to address the many unanswered questions in our field.

Epidemiological Study of Hepatitis A Infection in Eastern Bulgaria

BACKGROUND

Hepatitis A virus (HAV) infection is an acute, self-limited liver disease transmitted usually through the faecal-oral route via person-to-person contact. Bulgaria has intermediate HAV endemicity with higher susceptibility among adults and recurrent outbreaks.

AIM

As HAV infection is strongly related to human movements and represents a significant risk to travelers and migrants, as well as to local population receiving these groups, we set out to analyze the epidemiological data on hepatitis A in five of the largest tourist border regions of Bulgaria located in its eastern part: Varna, Shumen, Dobrich, Burgas and Yambol.

MATERIALS AND METHODS

We reviewed retrospectively all reported cases of acute hepatitis A in the eastern regions of Bulgaria over a 7-year period between 2008 and 2014.

RESULTS

A total of 2879 newly infected patients were registered during the study period, the number varying widely: from 190 cases in 2014 to 923 in 2012. The average incidence of HAV was higher in the south-eastern regions than in the northeastern regions (55.30%000 vs 15.04%000 respectively, p < 0.0001). The most affected age group in all regions was the 5-9-year olds (p < 0.0001) and males were significantly more susceptible to HAV (p = 0.02).

CONCLUSION

Hepatitis A is still a major public health problem in Bulgaria; there is a significant difference in the incidence of the disease between the regions in the south-east and those in the north-east and between the different age groups and sexes.

Pre-travel advice, attitudes and hepatitis A and B vaccination rates among travellers from seven countries†

BACKGROUND

Knowledge about the travel-associated risks of hepatitis A and B, and the extent of pre-travel health-advice being sought may vary between countries.

METHODS

An online survey was undertaken to assess the awareness, advice-seeking behaviour, rates of vaccination against hepatitis A and B and adherence rates in Australia, Finland, Germany, Norway, Sweden, the UK and Canada between August and October 2014. Individuals aged 18-65 years were screened for eligibility based on: travel to hepatitis A and B endemic countries within the past 3 years, awareness of hepatitis A, and/or combined hepatitis A&B vaccines; awareness of their self-reported vaccination status and if vaccinated, vaccination within the last 3 years. Awareness and receipt of the vaccines, sources of advice, reasons for non-vaccination, adherence to recommended doses and the value of immunization reminders were analysed.

RESULTS

Of 27 386 screened travellers, 19 817 (72%) were aware of monovalent hepatitis A or combined A&B vaccines. Of these 13 857 (70%) had sought advice from a healthcare provider (HCP) regarding combined hepatitis A&B or monovalent hepatitis A vaccination, and 9328 (67%) were vaccinated. Of 5225 individuals eligible for the main survey (recently vaccinated = 3576; unvaccinated = 1649), 27% (841/3111) and 37% (174/465) of vaccinated travellers had adhered to the 3-dose combined hepatitis A&B or 2-dose monovalent hepatitis A vaccination schedules, respectively. Of travellers partially vaccinated against combined hepatitis A&B or hepatitis A, 84% and 61%, respectively, believed that they had received the recommended number of doses.

CONCLUSIONS

HCPs remain the main source of pre-travel health advice. The majority of travellers who received monovalent hepatitis A or combined hepatitis A&B vaccines did not complete the recommended course. These findings highlight the need for further training of HCPs and the provision of reminder services to improve traveller awareness and adherence to vaccination schedules.

Multistate foodborne hepatitis A outbreak among European tourists returning from Egypt--need for reinforced vaccination recommendations, November 2012 to April 2013

Binary file ES_Abstracts_Final_ECDC.txt matches

[Vaccinations for international travelers]

Vaccinations are a prominent part of health preparations before international travel. They can avoid or significantly reduce the risk of numerous infectious diseases. Until recently, vaccination against yellow fever was the only obligatory vaccination. However, according to updated international health regulations, other vaccinations and prophylactic measures may be required at entry from certain countries. For all routine vaccinations as recommended in Germany, necessary revaccination and catch-up of missed vaccinations should be administered before travel. At most destinations the risk of infection is higher than in Germany. Hepatitis A vaccine is generally recommended for travelers to areas of increased risk, polio vaccine for all destinations where eradication is not yet confirmed (Asia and Africa). The indications for other travel vaccines must take into consideration travel destination and itinerary, type and duration of travel, individual risk of exposure as well as the epidemiology of the disease to be prevented. Several vaccines of potential interest for travel medicine, e.g., new vaccines against malaria and dengue fever, are under development.

Ηepatitis A and enteric fever in Greece, 2004-2011: a cross-sectional analysis

BACKGROUND

In Greece the number of international travellers has increased significantly the past decade.

AIM

To study the impact of international travels on the epidemiology of hepatitis A and enteric fever in Greece.

METHODS

We studied cases of hepatitis A and enteric fever notified through the National Surveillance System from January 1, 2004 through December 31, 2011.

RESULTS

A total of 921 cases of hepatitis A and 106 cases of enteric fever were notified; of them, 88 (9.5%) and 46 (43.4%) were travel-associated, respectively. Travellers returning from Eastern Europe and the Middle East accounted for most imported cases of hepatitis A (37 (43.5%) and 14 (16.5%) cases, respectively). The Indian subcontinent was the prevalent area of acquisition of travel-associated enteric fever, followed by the Middle East (35 (83.3%) and 4 (9.5%) cases, respectively). Foreign-born travellers accounted for 43 (48.8%) and 39 (86.6%) cases of travel-associated hepatitis A and enteric fever, respectively. Children <15 years accounted for 65.1% of hepatitis A cases and 7.7% among foreign-born travellers. Greek Roma accounted for 270 (29.3%) of all hepatitis A cases notified.

CONCLUSIONS

International travels have a significant impact on the epidemiology of enteric fever in Greece, affecting mainly foreign travellers. Hepatitis A carries a significant burden of morbidity among Greek travellers and children of foreign nationality. There is a need to improve travel medicine services for travellers travelling to developing countries.

Multicentric evaluation of new commercial enzyme immunoassays for the detection of immunoglobulin M and total antibodies against hepatitis A virus

A multicentric clinical study was conducted on representative sera from 1,738 European and U.S. subjects for the evaluation of new anti-hepatitis A virus enzyme immunoassays from Bio-Rad Laboratories. Comparison with reference DiaSorin S.p.A. tests confirmed the good performance of Bio-Rad assays (99.85% and 99.47% overall agreement in detecting total antibodies and IgM, respectively).

Defining infections in international travellers through the GeoSentinel surveillance network

International travellers are often exposed to a wide range of infections, most of which are a reflection of common diseases in the destination country. The consequences of acquiring such infections are serious and can be associated with substantial morbidity and mortality. Attempting to define the range of infections and the risk factors that are associated with acquiring them during travel to different regions worldwide will provide an evidence base for the development and implementation of effective preventative interventions. This Science and Society article focuses on the valuable function served by the GeoSentinel surveillance network in defining the range of infections in travellers.

Vaccination strategies against hepatitis A in travelers older than 40 years: an economic evaluation

BACKGROUND

In recent years, the number of travelers aged >40 years who acquire hepatitis A while traveling has increased. Therefore, there is a need to review hepatitis A vaccination protocols in travelers. The aims of the study were to assess immunity levels to hepatitis A virus (HAV) in international travelers >40 years and to determine the least costly immunization strategy.

METHODS

A serological examination of HAV antibodies in 427 international travelers aged >40 years traveling endemic zones was carried out. The prevalence of antibodies in each age group was assessed. The costs of two preventive strategies, direct vaccination of all subjects (independent of the immune status) or screening and subsequent vaccination of susceptible subjects were compared. The critical value of prevalence (CVP) (the value at which the costs for the two strategies are equal) was calculated.

RESULTS

Total prevalence of HAV antibodies was 78.9% [95% confidence interval (CI): 74.8-82.5] and was 80.0% (95% CI: 73.8-85.2) in men and 77.9% (95% CI: 71.9-83.2) in women. There was a positive association with age. In the 40 to 49, 50 to 59, 60 to 69, and 70 to 95 years age groups, the prevalence rates were 62.6 (95% CI: 53.8-71.5), 76.8 (95% CI: 70.0-82.7), 91.7 (95% CI: 85.2-95.6), and 97.5% (95% CI: 87.4-99.6), respectively. The CVP was 58.4% using two doses of vaccine.

CONCLUSIONS

The CVP was lower than the prevalence rate found in our international travelers. Therefore, we recommend systematic screening for HAV antibodies before selective vaccination of international travelers aged >40 years traveling to hepatitis A endemic zones.

Hepatitis A risk in travelers

BACKGROUND

Traveling to highly endemic areas for hepatitis A is increasing while the immunization level in travelers has been shown to be low in the countries studied.

METHODS

In this population-based study, we have estimated the incidence rate of travel-related hepatitis A during 1997 to 2005 by use of the Swedish notification system of communicable diseases and an ongoing national database on travel patterns. We have also acquired airport-based immunization data from 2007.

RESULTS

During the study period, 636 cases of travel-related hepatitis A were notified. Traveling to East Africa was associated with the highest incidence rate (14.1 cases/100,000 person months), followed by the Middle East (5.8/100,000 person months), and India with neighboring countries (5.6/100,000 person months). Visiting Friends and Relatives (VFR) travelers represented 83, 91, and 70% of the cases to these three regions. By age-group, the highest incidence was found in children 0 to 14 years (3.1/100,000 travelers) where 88% of the cases were VFR travelers. Incidence rate in unprotected travelers to East Asia, North Africa, and the Middle East was 2, 12, and 18 cases/100,000 person months, respectively. In 2007, 79% of the travelers were immunized against hepatitis A.

CONCLUSIONS

We conclude that travelers, and especially children, who are VFR in endemic areas constitute a high-risk group for acquiring hepatitis A infection, while the risk for unprotected tourists to East Asia is low.

Seroepidemiology of hepatitis A among Greek children indicates that the virus is still prevalent: Implications for universal vaccination

A national cross-sectional seroprevalence survey was conducted in order to evaluate the current seroepidemiology of hepatitis A among 1,383 children, aged 0-14 years, residing in Greece. Stratification of the study population was conducted according to age and area of residence. Sera from study participants were tested for the presence of anti-HAV IgG antibodies. Immigrant children, as well as children residing in rural areas, had lower immunization rates. Among unvaccinated children, the seroprevalence rate of anti-HAV was 17.1%. Nationality was shown to have a marginally significant effect since non-immunized immigrant children had a higher seroprevalence rate (22.4% vs. 15.9%, OR = 1.52, P = 0.064). Significant differences between geographic areas for both vaccination coverage and natural immunity were observed. The study findings indicate that hepatitis A is prevalent in Greece and therefore universal infant hepatitis A immunization should be implemented.

Hepatitis A among Danish travellers 1980-2007

The authors present a descriptive study on hepatitis A among Danish travellers in the period 1980-2007 based on data from a large survey among 26,640 Danes regarding travel habits, as well as national surveillance and population data. There are five messages to be read from the results: (1) The incidence of hepatitis A is declining at most destinations worldwide. (2) Reported incidence rates tend to overestimate the risk for the average tourist because they include immigrants visiting friends and family in the country of origin. (3) The immunization strategy in Denmark (leaving it up to the individual traveller to seek advice and pay for the immunization) seems to work well for most Danish travellers as 75% travelled immune. (4) Danes travel very frequently to hepatitis A endemic areas and will spend on average 6 months in endemic areas from the age of 18 till 79. (5) 80% of all incident cases 2002-2006 were immigrants or children of immigrants. The immunization strategy is not effective in this group. In conclusion, the risk of acquiring hepatitis A abroad is low for the average ethnic Danish tourist, while it is high in immigrants and their children. Thus, special focus on this group of travellers is warranted.

Seroepidemiology of hepatitis B virus infection: analysis of mass screening in Hawaii

BACKGROUND

Although hepatitis B seroprevalence has been studied extensively in California and New York, detailed information for other high-risk areas in the United States is lacking. To study current prevalence and risk for hepatitis B virus (HBV) infection in Hawaii, we analyzed cross-sectional data from Hawaii residents screened between July 2003 and April 2006.

METHODS

We retrospectively reviewed the screening records of 3,989 participants recruited at health fairs and clinics. Prevalence and risk factors for HBV infection were estimated using univariate and multivariate logistic regression models.

RESULTS

Total prevalence of hepatitis B surface antigen (HBsAg) was 3.6%. Gender, age, and ethnicity were independently associated with HBsAg seropositivity. In a multivariate logistic regression model, males were at increased risk for HBsAg compared with females (odds ratio [OR] = 1.53, 95% confidence interval [CI]: 1.09-2.16) and persons aged 70 years or older were less likely to test positive than those younger than 30 (OR = 0.25, 95% CI: 0.11-0.61). In addition, multivariate ORs of HBsAg seropositivity were 3.24 (95% CI: 1.04-10.09), 4.13 (95% CI: 1.66-10.29), and 7.47 (95% CI: 2.52-22.11) for Vietnamese, Chinese, and Pacific Islanders, respectively, compared with Whites.

CONCLUSIONS

This study furthers current knowledge of HBV epidemiology in areas with large populations of high-risk immigrants and demonstrates the relevance of screening programs for hepatitis B.