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Abstract

  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Declaration of Interests
  8. References

Background European studies indicate that up to 67% of travelers traveling abroad participate in activities that put them at risk of exposure to hepatitis B. Australians are increasingly traveling to destinations where hepatitis B is highly endemic, such as Asia, and are likely to have similar levels of involvement in activities with an associated risk of hepatitis B exposure.

Method A series of annual telephone surveys of approximately 500 randomly selected Australian overseas travelers have been conducted under the auspice of the Travel Health Advisory Group over the years 2001 to 2003. The surveys examined the extent to which travelers seek pretravel health advice, what immunizations they receive and what risks they are exposed to during travel including the risk of hepatitis B and other blood-borne virus acquisition.

Results In the 2003 survey, 281 (56%) of the 503 people interviewed had visited at least one country with high or medium hepatitis B endemicity on their most recent overseas trip in the past two years. Approximately a third of travelers undertook one or more activities that were considered to be associated with increased risk of potential hepatitis B exposure. Less than half the travelers (46%) had been vaccinated against hepatitis B.

Conclusions The results have implications for the individual traveler, as well as to the broader community. Infected travelers can be an important source of hepatitis B into their own home communities. Improved advice and clear recommendations for hepatitis B vaccination are needed to avoid infection.

Hepatitis B remains highly endemic in many parts of the world and continues to pose a risk not only to nonimmune travelers to these regions but also to their close contacts on returning home. Although the risk of hepatitis B has been best documented in extended-stay travelers, short-stay travelers also are at risk.1,2 Between 1995 and 2000, 12% of the reported cases of hepatitis B in England and Wales (UK) were associated with overseas travel, most often to countries with high endemicity or medium endemicity (83% of cases where the destinations were known).3

As well as the region of travel, the behavior of the travelers while abroad is important in determining their individual risk of hepatitis B exposure. In the UK data and in other studies, the most frequently cited means of transmission were medical treatment (which is usually unexpected) and heterosexual sex.3,4 The holiday spirit often leads to less inhibited sexual behavior and higher levels of risk taking that may result in accident or injury requiring medical attention. A survey of young Australians traveling to Thailand found that 57% of single individuals indicated a possible or definite intention to have sex while abroad, of which, 82% reported that they would use condoms 100% of the time.5 However, despite good intention, a relaxed holiday mood often results in people having unprotected casual sex.6–9 In a small survey of medical students, only 56% of those who reported a new sexual partner on holiday had always used a condom.7

Zuckermann and Steffen estimated about 67% of European travelers had a potential risk of hepatitis B exposure due to their country of destination and activities in those destinations.10 Given that large numbers of Australian who travel to areas of high and medium hepatitis B endemicity (particularly in Asia),11 it is likely that they would have similar levels of risk; however, there are few local studies ascertaining this risk. To address this and other issues, such as the level of pretravel health advice and immunization received, a series of surveys among Australian travelers was carried out under the auspices of the Travel Health Advisory Group (THAG). This article presents collected information concerning the Australian traveler’s risk of hepatitis B exposure overseas. A companion article in this issue reports information about the level of pretravel advice as well as hepatitis A risk and vaccination among international travelers.12

Method

  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Declaration of Interests
  8. References

Over the period 2001 to 2003, a series of three annual telephone surveys was conducted in a random selection of urban Australians aged 18 years and over who had traveled overseas for business or pleasure within the previous 2 years. On each occasion, a market research company telephoned people from Australian mainland capital cities (Sydney, Melbourne, Brisbane, Perth, and Adelaide) using lists of telephone numbers generated at random from the telephone directory. Eligible respondents were identified, using screening questions regarding overseas travel in the past 2 years and their age, and then asked to participate in the survey. This process continued until approximately 500 people had been interviewed using a standard questionnaire. Additional details regarding the methodology are described in Zwar and Streeton.12

The survey covered demographic information, details of traveling history, pretravel advice received, vaccination status, and perceptions of risk from travel-related disease. Interviewees were asked about activities that may have exposed them to risk of hepatitis B and other blood-borne virus during their last overseas trip, using a checklist of potential risk situations, such as invasive medical procedures, attending to a bleeding person, and skin perforating cosmetic practices, etc.6,10,13–18 After being provided with a scripted explanation and details of ways in which hepatitis B can be transmitted, interviewees were asked to indicate their general sense or perception of their risk of contracting hepatitis B, first during their last overseas trip and second, while in Australia.

Analysis

Data are presented as percentages of the sample as a whole or of the subsets of interest within the sample. The chi-square test was used to assess the significance of differences between groups. The endemicity of countries visited by the interviewees was classified as high, medium, or low as defined by the US Centers for Disease Control and Prevention.19

Results

  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Declaration of Interests
  8. References

The data collected over the 3 years of the survey were consistent in terms of the demographics, destinations, duration of travel and of pretrip travel advice, and vaccination. The demographics for the samples over the 3 years are presented in a companion article in the issue.12 Over that period, there was little change in travelers’ knowledge or behavior while traveling. Because the more recent data are the most relevant and there were differences to the wording of the questions from year to year, which made the data not directly comparable, the results focus on information from the 2003 survey (Table 1).

Table 1.  Travelers’ demographics and details of last overseas trip in 2003 survey (n= 503)
Demographics and trip detailsAttributeNumber (%)
  • *

    As defined by the US Centers for Disease Control and Prevention, 2000. Destinations for the cohort of 503 were Asia (40%), northern Europe (34%), southern Europe (13%), North America (16%), Oceania including New Zealand (19%), Eastern Europe (3%), Africa (4%), Middle East (2%), South America (2%), and Central America (1%), with some having more than one destination.18

GenderMale186 (37)
Female317 (63)
Age (y)18–29114 (23)
30–49208 (41)
50 and older181 (36)
Endemicity* for hepatitis  B in country(s) visited on  last overseas tripHigh211 (42)
Medium70 (14)
Low222 (44)
Duration of travel on last  overseas trip (mo)Less than 1297 (59)
1–3136 (27)
3–640 (8)
More than 630 (6)

Survey Response Rate

In the search for eligible respondents, 9,634 telephone calls were made to contact 4,203 people. Screening questions excluded 83.8% of those contacted as ineligible for the study. Of the 679 eligible respondents, 503 (74%) completed the interview.

Traveler’s Risk

In the 2003 survey, 211 (42%) of respondents had visited at least one country with high hepatitis B endemicity during their most recent trip, and a further 70 (14%) had visited at least one country with medium hepatitis B endemicity. Most trips were of less than 4 weeks duration (59%). Younger and older travelers were equally likely to travel to high and/or medium hepatitis B endemicity countries; 63% of 18 to 29 year olds, 55% of 30 to 49 year olds, and 52% of those 50 years and older traveled to high/medium endemicity countries, p= 0.20 (χ2= 3.6, df= 2).

Overall, about a third of the travelers had been involved in activities or situations with potential for exposure to hepatitis B during their most recent trip overseas irrespective of the hepatitis B endemicity in their destinations (Table 2). A significant proportion of travelers had a new sexual contact (5%), and/or had medical (13%), or dental (2%) treatment while overseas. Younger people were more likely to have been exposed to at least one risky behavior or incident during their trip than older travelers; 59% of 18 to 29 year olds, 30% of 30 to 49 year olds, and 18% of those 50 years and older, p < 0.001 (χ2= 55.1, df= 2).

Table 2.  Participation in activities with risk of exposure to hepatitis B on last overseas trip, 2003 survey
Activity/incident with risk of hepatitis B exposure10,13–18Destination(s)
All (n= 503) n (%)High and medium endemicity (n= 281) n (%)
  • *

    Some individuals had more than one risk activity or incident.

Activities with risk of potential exposure
 Had any new sexual contacts with anyone who is not your regular partner23 (5)17 (6)
 Had new sexual contacts without condoms9 (2)7 (2)
 Had any injections15 (3)11 (4)
 Required a blood transfusion1 (0)0 (0)
 Had contact with others’ blood or gave first aid2 (0)2 (1)
 Required any dental procedures10 (2)5 (2)
 Had any piercing or tattoo7 (1)5 (2)
 Received any acupuncture1 (0)0 (0)
 Shared a razor/toothbrush with a newly met person4 (1)4 (1)
Activities leading to risk of potential exposure
 Rode a motorcycle or drove an off road vehicle53 (11)38 (14)
 Participated in any water sport other than swimming48 (10)33 (12)
 Participated in a contact sport such as football27 (5)17 (6)
 Received any sort of injuries31 (6)18 (6)
 Visited a doctor/nurse for any reason65 (13)40 (14)
Proportion of travelers with at least one risk factor162 (32)*106 (38)*

Hepatitis B Vaccination Status and Travel Advice

Overall, only 216 (43%) of those interviewed were vaccinated against hepatitis B either for this trip (n= 44) or on a previous occasion. Indeed, approximately half (46%) of interviewees who had been exposed to at least one risk factor for hepatitis B on their last trip were unvaccinated or unsure of their vaccination status for this infection. Travelers to high and/or medium hepatitis B endemicity countries were more likely to have been vaccinated against hepatitis B (52% of 281) than those visiting low hepatitis B endemicity countries (32% of 222), p < 0.001(χ2= 20.3, df= 1 Yates corrected); and younger travelers were more likely to be vaccinated than older travelers; 58% of 18 to 29 year olds, 51% of 30 to 49 year olds, and 24% of those 50 years and older, p < 0.001, (χ2= 42.3, df= 2).

As previously reported, only about a third of travelers visited a doctor or travel health clinic prior to their last overseas trip on average 36 (± 27) days before departure.11 Although younger people were slightly, though not significantly, more likely to see a doctor before travel (40% of those younger than 30 years compared to 32% of those aged 30 and older), overall only 11% of those consulting a doctor before travel received counseling about sexual health.

Perceptions of Hepatitis B

Understanding of hepatitis B as a travel-related infection and the knowledge of hepatitis B vaccine availability were generally poor. Although 45% of people correctly identified how hepatitis B was transmitted and another 22% had vague concept, only 19% of those interviewed specified hepatitis B as a travel-related infection, and only 25% were spontaneously (unprompted) aware of the availability of hepatitis B vaccines. However, in regards to the seriousness of hepatitis B, 79% rated hepatitis as very or extremely serious (compared to 71% for malaria and 77% for typhoid). In regards to their perceptions of risk, 35% of interviewees thought they were at risk of hepatitis B in Australia compared to only 12% while traveling overseas.

Discussion

  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Declaration of Interests
  8. References

Despite ongoing unease about terrorism, the number of Australians traveling overseas continues to increase.20 In this 2003 survey, 56% of Australian travelers had visited countries with high or medium endemicity for hepatitis B on their last overseas trip. In addition, about a third of those surveyed had encountered at least one situation that potentially exposed them to hepatitis B transmission, although in the majority of cases, this involved activities that could lead to risk of potential exposure, such as riding a motorcycle. A smaller proportion had a direct risk of exposure through contact with blood and body fluids. Overall, about half of the travelers to high and/or medium hepatitis B endemicity countries were vaccinated against hepatitis B, and only about half those potentially exposed to hepatitis B infection through a behavior or incident were vaccinated.

These findings have implications not only for the individual travelers but also for the broader community as infected travelers are a potential source of hepatitis B infection. In a large UK study of hepatitis B incidence and transmission, 12% of cases were considered travel related.3 Almost half the cases (45%) were associated with travel to a medium endemicity country and 38% to a high endemicity country. Among those cases associated with travel to medium endemic countries, transmission through medical treatment and heterosexual sex were each reported by about a third of individuals (36 and 34%, respectively), while 70% of those who visited a high endemic country reported transmission by heterosexual sex.3 In the current survey, 14% of travelers to high/medium endemicity countries reported receiving medical treatment and 2% dental treatment, while 6% reported a new sexual contact.

As reported in other studies, potential exposure to hepatitis B during overseas travel was often unwitting.10 Only 45% of interviewees correctly identified the means of hepatitis B transmission, and only 19% thought of it as an infection related to overseas travel. Indeed, more people perceived a risk of hepatitis B in Australia, 35%, compared to 12% perceiving a risk overseas. Mulhall and colleagues made a similar observation in young travelers to Thailand.5 In their survey, travelers did not perceive a higher personal risk of acquiring acquired immunodeficiency syndrome (AIDS) in Thailand compared to Australia, even though they were aware of the higher prevalence of the disease in Thailand.5 The lack of knowledge and perception of the risk indicates the need for greater education of overseas travelers about blood-borne and sexually transmitted infections, especially as there are no vaccines for human immunodeficiency virus and hepatitis C infections. Of particular concern is the low rate of sexual counseling (11%) reported by those who had sought pretrip travel advice from a general practitioner or a travel health clinic.

Young adults aged 18 to 29 years in the survey were more likely to have been vaccinated against hepatitis B than older individuals. This is most likely due to the national adolescent vaccination program for 10 to 16 year olds, which was introduced in Australia during 1998.21 Nevertheless, 34% of young adults indicated they were not vaccinated and another 8% were unsure of their vaccination status. It is important to note that the Australian Immunization Handbook recommends that all young adult travelers should be vaccinated against hepatitis B.22 The recommendation takes into consideration that in developed countries like Australia, hepatitis B is a disease of young adulthood, the time when risk behavior is most likely.23 This was also apparent in the survey, with younger travelers being more likely than older travelers to have participated in at least one risky behavior or activity for hepatitis B on their last overseas trip.

However, there are significant barriers to pretrip hepatitis B vaccination related first, to the relatively few people who seek medical advice before traveling, roughly a third of those in this survey, and second, the timing of these visits, on average 36 days before travel in this survey. This does not allow time for the standard 0, 1, 6 months hepatitis B vaccination schedule. However, the recent availability of an accelerated schedule of hepatitis B vaccination (0, 7, and 21 days with a booster at 12 months24) means that in the future more travelers can be adequately immunized before departing overseas. Additionally, there are now abundant data to support the flexibility of dosing with rapid schedules approved and a 2-dose regime available for adolescents.25

There may also be issues with prioritizing vaccination. Decisions about vaccination depend on each individual’s risk assessment. For extended-stay travelers to endemic countries, frequent travelers and younger travelers, hepatitis B should perhaps have a higher priority. Indeed for the unvaccinated Australian traveler, the pretrip consultation could be viewed as an opportunity for hepatitis B catch-up vaccination.22 The availability of a combine hepatitis A and B vaccine can often assist prioritization, and here also, there are several rapid schedules that can provide protection for travelers presenting 3 to 4 weeks before departure.26

As with all telephone surveys, the study results have a number of limitations including the potential for sampling bias, related to telephone ownership, response, and recall bias. Although the latter is more likely to sway the results toward a cautious and more conservative estimate of risk, since only the more significant events are likely to be recalled and the perhaps more numerous less obvious risk events forgotten. Also, there is an assumption that an individual reporting hepatitis B vaccination is adequately immunized, which is not necessarily the case, if the vaccination schedule was incomplete. Despite these limitations, telephone surveys are generally the most cost-effective means of answering questions about behavior across a community.

In conclusion, a substantial proportion of Australian travelers, including those traveling to countries with medium and/or high hepatitis B endemicity, undertake activities leading to potential for risk of hepatitis B and other blood-borne virus exposure. Improved pretrip advice and appropriate recommendations for hepatitis B vaccination are needed to avoid the risk of transmission. Given the reported safety, long-term efficacy, and relatively low cost, hepatitis B immunization should be promoted more widely among travelers. The rapid immunization schedules and the availability of combined hepatitis A and hepatitis B vaccine, both of which do not require further boosting after primary dosing in immunocompetent individuals, should facilitate this.27–29

Acknowledgments

  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Declaration of Interests
  8. References

This work was carried out under the auspices of the THAG, Sydney South, NSW. Funding from GlaxoSmithKline Australia Ltd supports THAG activities. Statistical assistance with data analysis was provided by Mr Stephen Linz, GlaxoSmithKline Australia. THAG member organizations are the Australian Federation of Travel Agents (Ms Marie Allom); MASTA—Minding Your Health Abroad (Dr Bernard Hudson); Royal Australian College of General Practitioners (Professor Nicholas Zwar); School of Public Health and Tropical Medicine, James Cook University (Associate Professor Peter Leggat), Rede-Health International (Dr Bob Kass), Qantas Airways (Ms Bronwyn Claxton), and Youth Hostels Association Australia (Mr Ben Fryer).

Declaration of Interests

  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Declaration of Interests
  8. References

The survey was carried out under the auspices of the THAG. GlaxoSmithKline provides financial support for various activities of THAG including the survey. Dr Catherine Streeton is an employee of GlaxoSmithKline. Prof Nicholas Zwar is a member of THAG and has acted as a consultant to GlaxoSmithKline in an unrelated field to travel medicine. He has received travel grants from GlaxoSmithKline and Pfizer.

References

  1. Top of page
  2. Abstract
  3. Method
  4. Results
  5. Discussion
  6. Acknowledgments
  7. Declaration of Interests
  8. References
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