Hepatitis A is considered as one of the

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1 Trends in Knowledge, Attitudes, and Practices of Travel Risk Groups Toward Prevention of Hepatitis A: Results From the Dutch Schiphol Airport Survey 2002 to Perry J.J. van Genderen, MD, PhD,, Pieter P.A.M. van Thiel, MD, PhD, Paul G.H. Mulder, MSc, PhD, and David Overbosch, MD, PhD, on behalf of the Dutch Schiphol Airport Study Group Harbor Hospital and Institute for Tropical Diseases, Rotterdam, The Netherlands; Travel Clinic Havenziekenhuis, Rotterdam, The Netherlands; Division of Infectious Diseases, Tropical Medicine and Aids and Center for Infection and Immunity Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Biostatistics, Erasmus University Hospital, Rotterdam, The Netherlands DOI: /j x Background. Previous studies investigating the travelers knowledge, attitudes, and practices (KAP) profile indicated an important educational need among those traveling to risk destinations. Initiatives to improve such education should target all groups of travelers, including business travelers, those visiting friends and relatives (VFR), and older adult travelers. Methods. In the years 2002 to 2009, a longitudinal questionnaire-based survey was conducted at the Dutch Schiphol Airport with the aim to study trends in KAP of travel risk groups toward prevention of hepatitis A. The risk groups last-minute travelers, solo travelers, business travelers, travelers VFR, and older adult travelers were specifically studied. Results. A total of 3,045 respondents were included in the survey. Travelers to destinations with a high risk for hepatitis A had significantly less accurate risk perceptions (knowledge) than travelers to low-to-intermediate-risk destinations. The relative risk for hepatitis A in travelers to high-risk destinations was probably mitigated by less intended risk-seeking behavior and by higher protection rates against hepatitis A as compared with travelers to low-to-intermediate-risk destinations. Logistic regression analyses showed that an age >60 years was the only significant determinant for improvement of their knowledge. Trend analyses showed a significant change over time in attitude toward more risk-avoiding behavior and toward higher protection rates against hepatitis A in travelers to high-risk destinations. The KAP profile of the risk groups travelers VFR (irrespective of hepatitis A risk of their destination) and solo as well as last-minute travelers to high-risk destinations substantially increased their relative risk for hepatitis A. Conclusions. The results of this longitudinal survey in Dutch travelers suggest an annual 5% increase in protection rates against hepatitis A coinciding with an annual 1% decrease in intended risk-seeking behavior. This improvement may reflect the continuous efforts of travel health advice providers to create awareness and to propagate safe and healthy travel. The KAP profile of travelers visiting friends and relatives (VFR) and solo as well as last-minute travelers to high-risk destinations substantially increased their relative risk for hepatitis A. These risk groups should be candidates for targeted interventions. Hepatitis A is considered as one of the most common vaccine-preventable travel-related diseases globally. 1 Despite access to efficient and safe vaccines, the immunization level in travelers to endemic areas is shown to be low in most countries 1 and hepatitis A is still a frequently reported disease Corresponding Author: Perry J.J. van Genderen, MD, PhD, Harbor Hospital and Institute for Tropical Diseases, Haringvliet 72, 3011 TG Rotterdam, The Netherlands. p.van.genderen@havenziekenhuis.nl among international travelers. 2 4 In addition, travel may also play an important role in unexpected outbreaks of hepatitis A in non-endemic countries like the Netherlands. 5 In fact, it has been shown that due to import of hepatitis A by immigrant children returning from family visits in Morocco and Turkey and secondary cases in the Netherlands among siblings and schoolmates caused a time-related increase in notifications of adults who became infected in the Netherlands. 6 In the years 2002 to 2003, the European Travel Health Advisory Board conducted a cross-sectional 2011 International Society of Travel Medicine, Journal of Travel Medicine 2012; Volume 19 (Issue 1): 35 43

2 36 van Genderen et al. pilot survey in several European airports including the Dutch Schiphol Airport to evaluate current travel health knowledge, attitudes, and practices (KAP) and to determine where travelers going to developing countries obtain travel health information, what information they receive, and what preventive travel health measures they adopt. 7,8 The results of that particular study demonstrated an important educational need among those traveling to risk destinations. Initiatives to improve such education should target all groups of travelers. In the Netherlands, a similar survey has been done each year between 2002 and 2009 (except for the year 2006), giving a unique opportunity to study trends in KAP of travelers toward prevention of hepatitis A. In this study, we report our findings regarding these trends with a special focus on the risk groups last-minute travelers, solo travelers, business travelers, travelers VFR, as well as older adult travelers. Methods Questionnaires and Survey The survey was conducted as previously described. 3 In brief, self-administered, anonymous questionnaires were randomly distributed at the departure gate of Schiphol Airport, Amsterdam, the Netherlands, while passengers were waiting to board. Intercontinental flights to destinations with an intermediate or high risk for hepatitis A, hepatitis B, or malaria were preferably selected. The survey was always done in the same period of the year, namely the months October or November. Travelers participated on a voluntary basis; no incentive was provided, except for a leaflet with information on hepatitis A, hepatitis B, and malaria. Trained interviewers were present to distribute the questionnaires, to answer questions if necessary, and to check the completeness of the responses collected. When possible, these interviewers copied the information from the travelers vaccination records. Travelers were allowed to participate if they were 18 years of age or older, and able to fully understand the language of the questionnaires. They also had to be resident in the Netherlands; thus, nationals of a developing country were only asked to participate if they were actually living in the Netherlands. These criteria were checked by the interviewers when distributing the forms. Afterwards, completed questionnaires from travelers who did not meet all the inclusion criteria were either excluded by the interviewers or rejected from the final analysis. Two kinds of questionnaires were distributed among the participants, depending on the precise destination. The malaria questionnaire (Q-mal) focused on malaria and its prevention and treatment and these questionnaires were distributed only to travelers with destinations in or close to malaria-endemic areas. The vaccine questionnaire (Q-vacc) targeted the vaccine-preventable travel-related diseases hepatitis A and B. Both questionnaires had a common part on personal characteristics (age, gender, nationality, residence, profession), on information regarding the travel (destination, duration, purpose, travel companions) and its preparation, and on the travelers perception of the risk of malaria, hepatitis A and B at their destination. However, as most malaria-endemic countries also carry a high risk for hepatitis A and B, the Q-mal questionnaire also contained several items dealing with the KAP toward prevention of hepatitis A and B. Definitions of Risk Groups Respondents with an age over 60 were arbitrarily classified as older adult travelers. Solo travelers were defined as those travelers who traveled alone. Business travelers were defined as those travelers who specifically stated that their main purpose for travel was business related. Last-minute travelers were defined as those travelers who planned their trip within 2 weeks from departure. Respondents who specifically stated that their main purpose for travel was to visit friends and relatives were considered VFRs. Determination of KAP Profile on Hepatitis A Knowledge of hepatitis A was determined by comparison of the risk for hepatitis A as perceived by the traveler with the actual risk for hepatitis A, as described. 8 To that end, all destinations (including those in malaria-endemic countries) were rated as low-, intermediate-, or high-risk destination for hepatitis A based on maps published by the Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA. 9 The accuracy (correct risk perception) was expressed as a percentage of maximal correctness, ranging from 0 to 100%. To determine the attitude (intended risk behavior) of participants toward hepatitis A, all participants were asked if they were planning to consume possibly contaminated food items such as tap water, ice cubes, raw shellfish, ice-cream, and salads. Each affirmative answer was scored with one point, whereas a negation was scored with 0 points. The final attitude score could range from 0 to 5; for convenience, the score was transformed to a 0 to 100% scale with the maximal risk score set at 100%. To have an indication of their practice (protection rate), travelers were considered to be protected against hepatitis A if they were either vaccinated for this trip, or fully vaccinated in the past (at least two doses of hepatitis A vaccine, or three doses of combined hepatitis A and B vaccine), or naturally immune; others were considered to be unprotected. Protection rate was expressed as a percentage of protected individuals and could range from 0 to 100%. To estimate the impact of KAP of the travel risk group of interest on relative risk for hepatitis A, a composite estimate was constructed by summing up the effects of the separate determinants. To that end, it was assumed that either a poor risk perception, intended risk-seeking behavior, or poor protection rates led to an equal increase in relative risk for hepatitis A.

3 Trends in KAP of Travel Risk Groups 37 Statistical Analysis Several statistical analyses were made between travelers to high- and to low-to-intermediate-risk destinations: on one hand the so-called between risk destinations analysis: eg, the comparison of VFRs traveling to high-risk destinations versus VFRs traveling to lowto-intermediate-risk destinations) and on the other hand the so-called within risk destination analyses: eg, the comparison of solo travelers to high-risk destinations versus the remaining (non-solo) travelers to high-risk destinations. To that end, differences in the pre-defined risk factor distributions between the two different risk destinations were tested using multiple logistic regression analyses, adjusted for subpopulation (14 subpopulations: two kinds of questionnaires by 7 interview years). Similar analyses were done for testing differences in risk between the two knowledge groups (accurate risk perception y/n) and between the two practice groups (protected y/n), allowing separate tests for low-to-intermediate- and high-risk destinations through entering the appropriate interaction terms into the models. The dependency of attitude (risk behavior score) on the risk factors was analyzed using multiple linear regression analyses, modeled similarly to the above mentioned logistic regression analyses. Those regression analyses also allow testing differences between the two risk destination groups in knowledge, attitude, and practice within specific risk groups. Finally, it was tested in appropriate multiple logistic and linear regression models if the strength of the effect of the predetermined risk factors on KAP showed a significant time trend over the years 2002 to Results Study Population Across all 7 years in the period from 2002 to 2009 (except year 2006) a total of 3,050 questionnaires were received, of which 3,045 fulfilled the entry criteria and were included in the analysis (Figure 1). Of the 3,045 respondents, 2,374 respondents traveled to destinations with a high risk for hepatitis A. The remaining 671 respondents traveled to a low-to-intermediaterisk destination. The general characteristics of all respondents, grouped by risk for hepatitis A in either a high-risk or a low-to-intermediate-risk destination, are shown in Table 1. Overall, 46.4% of responders were female and 53.6% were male. Almost 63% of the travelers to high-risk destinations and 38% of the travelers to low-to-intermediate-risk destinations were protected against hepatitis A. Travel Profile For 20.8% of the travelers since 2004 it was their first trip to a developing country (there was no firsttrip item in the questionnaires of 2002 and 2003). Overall, 63.9% indicated tourism as their purpose of travel. One in five to six responders were VFR, business Figure 1 Flowchart of the Dutch Schiphol Airport Survey. The yearly inclusions of respondents of the malaria questionnaires (Q-mal) and vaccination questionnaires (Qvacc) in the study are shown as well as reasons for exclusion. travelers accounted for 15.0%. Few responders traveled for missionary reasons or for voluntary missions (2.2%), for purpose of research or education (0.7%), or for other reasons (1.0%). Many travelers (41.6%) were accompanied by their partner or spouse; 869 persons (30.3%) were traveling alone, 6.9% with friends, 11.7% with children. Travelers to high-risk destinations planned to stay significantly longer at their destination than travelers to low-to-intermediate-risk destinations (p < 0.001) and obtained pre-travel health advice more frequently before departure (p < 0.001). Overall, 24.1% went abroad for 1 to 7 days, 40.2% for 8 to 14 days, 26.1% for 15 to 28 days, and 9.5% for more than 28 days. Egypt was the most common high-risk destination (N = 418; 17.6%), followed by Gambia (15.7%) and Mexico (7.6%), whereas among the low-to-intermediate-risk

4 38 van Genderen et al. Table 1 General characteristics of 3,045 respondents in relation to the hepatitis A risk profile of their destination High-risk destination Low-to-intermediate-risk destination p Value* N % N % 2, Sex n.s. Male 1, Female 1, Age >60 y Travel duration <0.001 <7 d d d >28 d Travel health preparation Pre-travel information <0.001 No Yes 1, Information source <0.001 Travel clinic/public health service Company doctor General practitioner/pharmacy Other Time frame booking departure <0.001 <7 d d d >28 d Purpose for travel <0.001 Tourist 1, Business VFR Missionary/volunteer Research Other Travel profile Solo traveler Travel with spouse Travel with children Travel with group Travel with friends Other Travel experience (intercontinental) in last 5 y n.s. No Yes 1, Most popular destinations Egypt Turkey Gambia Dominican Republic Mexico Malaysia Thailand Croatia China Cuba VFR = visiting friends and relatives. p Value for comparison of high-risk destinations versus low-to-intermediate-risk destinations. All data are given as a percentage of either the total number of respondents to high-risk destinations (ie, N = 2, 374) or as a percentage of the total number of respondents to destinations (ie, N = 671).

5 Trends in KAP of Travel Risk Groups 39 destinations Turkey (N = 428; 63.8%) was the most common destination, followed by the Dominican Republic (7.9%) and Malaysia (5.8%) (Table 1). Travel Health Preparations The majority of travelers (65.5%) had sought health information about their destination before departure. This was done more than 1 month before leaving by 47.5% of the responders; 25.1% started preparing 2 weeks to 1 month before departure, 15.7% did so 1 to 2 weeks in advance, and 11.6% did so less than 1 week before leaving. Of those who had not sought health information, the majority stated that they already knew what to do. The most common sources since 2004 for travel health advice to high-risk destinations were the travel clinic or public health service (66.4%) followed by general practitioner (GP) or family doctor in 21.3% of the respondents. For low-to-intermediate-risk destinations the travel clinic or public health service was consulted in 53.2% of the respondents, whereas the GP or family doctor was consulted in 27.8% of the cases. In the 2002 and 2003 questionnaires there was no item concerning source of advice. There were no significant trends over the years in the proportion of travelers to high-risk destinations seeking travel health advice (p = 0.315). In contrast, trend analyses in travelers to low-to-intermediate-risk destinations showed a decrease over the years in the proportion of travelers seeking travel health advice (p = ). Pre-defined Risk Groups The group of older adult travelers comprised 439 respondents. Of them, 365 (83.1%) traveled to a highrisk destination. The group of last-minute travelers comprised 545 respondents; 474 (87.0%) of them traveled to a high-risk destination. Of all respondents, 869 respondents traveled alone and were classified as solo travelers; 650 (74.8%) of them traveled to a high-risk destination. The group of business travelers consisted of 453 individuals of whom 330 (72.8%) traveled to destinations rated as a high risk for hepatitis A. The group of VFRs consisted of 521 respondents; 390 (74.9%) of them traveled to a high-risk destination (Table 1). Knowledge, Attitude, and Practice on Hepatitis A Analysis of Risk Groups Older Adult Travelers Older adult travelers to either high-risk (p = 0.076) or low-to-intermediate-risk destinations (p = 0.434) did not better prepare their vacation than younger-aged travelers to the same risk destination. Older adult travelers visited high-risk destinations more frequently (Table 1). The risk perception and protection rate of older adult travelers to either high-risk or low-tointermediate-risk destinations was comparable to that of younger travelers (Table 2). Older adult travelers, however, had less intended risk-seeking behavior than younger travelers, irrespective of the hepatitis A risk at the planned destination. As a consequence, as shown in Table 3, the composite risk estimate of KAP of older adult travelers suggested a slight reduction of relative risk for hepatitis A. Solo Travelers Solo travelers to either high- (p < 0.001) or lowrisk destinations (p < 0.001) had less preparation for their travel than non-solo travelers to the same risk destination. Solo travelers traveled more frequently to low-to-intermediate-risk destinations than to high-risk destinations (Table 1). Their risk perception was less than that of non-solo travelers, but this finding was only present for high-risk destinations (Table 2). More riskseeking behavior was seen in solo travelers compared to non-solo travelers. Also, solo travelers had significantly lower protection rates than non-solo travelers to highrisk destinations (Table 2). The composite risk estimate of the KAP of solo travelers suggested a substantial increase in relative risk for hepatitis A for solo travelers to high-risk destinations (Table 3). Business Travelers Business travelers to either high- (p < 0.001) or low-to-intermediate-risk destinations (p < 0.001) less frequently sought travel health advice than non-business travelers. Business travelers to high-risk destinations had more intended risk behavior than non-business travelers, but had comparable protection rates against hepatitis A and risk perception as non-business travelers, irrespective of the risk profile of the destination (Table 2). As a consequence, the KAP profile of business travelers to high-risk destinations slightly increased the relative risk for hepatitis A (Table 3). Last-Minute Travelers Last-minute travelers had comparable travel health preparation in comparison to regular travelers (highrisk destinations p = 0.199; low-to-intermediate-risk destinations p = 0.111). The risk perception of lastminute travelers to either high- or low-to-intermediaterisk destinations was significantly lower than that of regular travelers (Table 2). Last-minute travelers to high-risk destinations had more intended risk-taking behavior than regular travelers. Last-minute travelers to either high- or low-to-intermediate-risk destinations had significantly lower hepatitis A protection rates than regular travelers to the same risk destinations. As a consequence, the KAP profile of last-minute travelers to high-risk destinations was estimated to substantially increase the relative risk for hepatitis A, whereas the relative risk was moderately increased for last-minute travelers to low-to-intermediate-risk destinations (Table 3).

6 40 van Genderen et al. Table 2 Knowledge, attitude, and practice of travel risk groups to destinations with high and low-to-intermediate risk for hepatitis A Knowledge High-risk destinations Low-to-intermediate-risk destinations No. of cases Total number % high-risk destinations ) No. of cases Total number % destinations ) p Value (highvs destinations ) Overall 839 2, n.a n.a <0.001 Older adult traveler n.s n.s <0.001 Solo traveler n.s <0.001 Business traveler n.s n.s <0.001 Last-minute traveler 314 1, < < < VFR <0.001 Attitude n Mean SD high-risk destinations ) n Mean SD destinations ) p Value (high- vs destinations ) Overall 1, n.a n.a <0.001 Older adult traveler < < n.s. Solo traveler < n.s Business traveler n.s Last-minute traveler < n.s < VFR < No. of Practice cases Total number Mean high-risk destinations ) No. of cases Total number Mean destinations ) p Value (high- vs destinations ) Overall n.a n.a <0.001 Older adult traveler n.s n.s Solo traveler n.s <0.001 Business traveler n.s n.s <0.001 Last-minute traveler < < < VFR < < <0.001 n.a. = not applicable; n.s. = not significant; VFR = visiting friends and relatives. Last-minute = information sought: none or within 14 days before departure. Knowledge was defined as a percentage of maximal accurate risk perception (0 100% scale). Attitude was defined as a percentage of maximal risk behavior (0 100 scale). Practice was scored only in the vaccination questionnaires as a percentage of the maximal protection (0 100% scale). p Value of comparison of a given risk group versus the remainder of travelers to a high-risk destination. p Value of comparison of a given risk group versus the remainder of travelers to a low-to-moderate risk destination. p Value of comparison of a given risk group to a high-risk destination versus the same risk group to a low-to-intermediate-risk destination.

7 Trends in KAP of Travel Risk Groups 41 Table 3 Estimates of the impact of the knowledge, attitude, and practice (KAP) of travel risk groups on their relative risk of hepatitis A Risk group Knowledge Attitude Practice Impact on relative risk of hepatitis A Destinations with a known high risk of hepatitis A Older adult traveler No effect on risk Decrease in risk No effect on risk Slight decrease in risk Solo traveler Increase in risk Increase in risk Increase in risk Substantial increase in risk Business traveler No effect on risk Increase in risk No effect on risk Slight increase in risk Last-minute traveler Increase in risk Increase in risk Increase in risk Substantial increase in risk VFR Increase in risk Increase in risk Increase in risk Substantial increase in risk Destinations with a known low-to-intermediate risk of hepatitis A Older adult traveler No effect on risk Decrease in risk No effect on risk Slight decrease in risk Solo traveler No effect on risk No effect on risk No effect on risk No effect on risk Business traveler No effect on risk No effect on risk No effect on risk No effect on risk Last-minute traveler Increase in risk No effect on risk Increased in risk Moderate increase in risk VFR Increase in risk Increase in risk Increase in risk Substantial increase in risk VFR = visiting friends and relatives. Visiting Friends and Relatives (VFRs) VFRs sought travel health advice less frequently than non-vfr travelers (high-risk destinations p < 0.001; destinations p < 0.001). In this study, VFRs traveled more frequently to low-to-intermediate-risk destinations (Table 1). VFRs to both high- and lowto-intermediate-risk destinations had lower protection rates and less adequate risk perceptions than non- VFR travelers and had more intended risk-taking behavior than non-vfr travelers (Table 2). As a consequence, the KAP profile of VFRs substantially increased the relative risk for hepatitis A, irrespective of the actual hepatitis A risk of their destination (Table 3). Trends in Knowledge, Attitude, and Practice of Travelers Toward Hepatitis A Knowledge (Accurate Risk Perception) Logistic regression analyses showed that an age >60 years was the only significant determinant for improvement of risk perception. However, over the years there were no significant trends in travelers knowledge, defined as an accurate risk perception of hepatitis A, neither for the group as a whole nor for the pre-defined risk groups. Thus, there were no significant trends over the years in the knowledge of travelers to either low- or high-risk destinations. Attitude (Intended Risk Behavior) In contrast to travelers to low-to-intermediate-risk destinations, there was a significant trend in the attitude of travelers to high-risk destinations. The intended risk behavior to high-risk destinations decreased with 0.98% per year ( interval , p = 0.005). There were no significant trends in the attitude of either older adult travelers, solo travelers, business travelers, last-minute travelers, or VFRs to either high- or lowto-intermediate-risk destinations (data not shown). Practice (Protection Rate) In contrast to travelers to low-to-intermediate-risk destinations, there was a significant trend in the protection rate of travelers to high-risk destinations. The odds ratio of protection increased by 5.2% per year ( interval %, p = 0.027). However, there were no significant trends in the protection rate of the travel risk groups of interest (not shown). Discussion The results of the European Airport Survey demonstrated an important educational need among those traveling to risk destinations. 7 In line with our study, it was suggested that travel health advice providers should continue their efforts to make travelers comply with the recommended travel health advice, especially certain risk groups. The present study enabled us to provide indepth feedback on these efforts by analyzing the trends in KAP of Dutch travelers, including those belonging to a certain risk group, over an 8-year observation period. Although we did not observe a significant increase in the proportion of travelers to high-risk destinations seeking travel health advice over the years, some findings in our study are certainly noteworthy. In general, travelers to high-risk destinations had significantly less accurate risk perceptions than travelers to destinations. However, the risk of acquiring hepatitis A in travelers to high-risk destinations may have been reduced by less intended risk-seeking behavior and by higher protection rates against hepatitis A compared to travelers to lowrisk destinations. A plausible explanation for the higher protection rates against hepatitis A may be that travelers to high-risk destinations seek travel health advice more frequently than travelers to destinations. Furthermore, trend analyses clearly demonstrated that the attitude of travelers to high-risk destinations also significantly improved over time, although the observed reduction of intended risk behavior was small

8 42 van Genderen et al. (about 1% per year). This improvement may reflect the continuous efforts of travel health advice providers to propagate safe and healthy travel. Moreover, a significant increase in the overall protection rates against hepatitis A was noted over the years with an annual 5% increase in protection rate since the start of this questionnaire-based survey in Since hepatitis A vaccinations in the Netherlands are delivered by travel health advice providers, the annual increase in hepatitis A protection rates may be a reflection of an increasing awareness of Dutch travelers for the need for proper travel health advice. The attack rates of hepatitis A among Dutch travelers to developing regions have declined between 1995 and This decline correlated with improved hygienic standards at the travel destination. 10 Improvements in travelers risk perception, risk behavior, and protection may also have contributed, but were not assessed in that study. Our results show that the attitude toward risk-seeking behavior and protection rates have also improved over time, which might have added to the observed decline in hepatitis A attack rates among Dutch travelers. Previous studies also suggested that initiatives to improve travel health education should target all groups of travelers, including business travelers, those VFR, and the older adults. 7,8 Our questionnaire-based survey specifically focused on the impact of the composite KAP profile of five pre-defined risk groups, eg, the group of older adult travelers, the group of solo travelers, the group of business travelers, last-minute travelers, and those VFR, on their relative risk for hepatitis A. When focusing on older adult travelers, our data suggested that although they traveled more frequently to high-risk destinations the KAP of older adult travelers had no significant impact on their relative risk for hepatitis A. In fact, the risk profile may even be lower than anticipated as older adult travelers had more intended risk-avoiding behavior than their younger counterparts to the same risk destination. Although an age above 60 years was recognized as an important determinant for improving risk perception, the knowledge and protection rate of older adult travelers did not differ significantly from youngeraged travelers nor were there significant changes in knowledge and practice of older adult travelers over the years. Recent hepatitis A seroprevalence data from the Netherlands indicated that people born after the Second World War showed lower seroprevalence rates compared to people born before or during this war. 11 This decrease is probably causally related to increased hygienic standards hereafter but also indicates an increasing age of the susceptible population. In contrast, the KAP of solo travelers, in particular to high-risk destinations, increased their relative risk of hepatitis A. The risk perception of solo travelers was lower than non-solo travelers, they had more intended risk behavior and their protection rates were lower. However, the increased relative risk of solo travelers may have been reduced, considering solo travelers more frequently visited destinations with a low-tointermediate risk for hepatitis A. The composite risk estimate of the KAP of business travelers to high-risk destinations suggested only a slight increase in relative risk for hepatitis A, which was mainly due to more risk-seeking behavior, whereas business travelers to low-to-intermediate-risk destinations had a comparable risk profile as compared with non-business travelers. Interestingly, the risk estimate of the KAP profile of last-minute travelers to high-risk destinations suggested a substantially increase in relative risk for hepatitis A. The protection rates of last-minute travelers were significantly lower than that of regular travelers and they had more intended risk-seeking behavior. As suggested in other studies, 2,6 the KAP profile of VFRs resulted in a clear increase in relative risk for infectious diseases like hepatitis A. VFRs to high-risk destinations had significantly lower protection rates, had more intended risk-seeking behavior, and had the lowest risk perception of hepatitis A. Strategies to reach this group for proper travel health advice are definitely needed since they are among the travelers with the highest risk profile. 12 Interestingly, a previous study showed that in second-generation immigrants, born in the Netherlands, the seroprevalence did not differ from that of adults of Western origin. 13 Together with clear intended risk-taking behavior this group is certainly at risk for acquiring hepatitis A at a later age. Through addressing hepatitis A risk among those VFR, we would not only protect individuals but may also potentially disrupt the transmission cycle in communities abroad and back home. 2 Targeted routine hepatitis A vaccination of groups at risk could be an effective approach, as was shown with hepatitis A vaccination of children of Turkish and Moroccan origin in the Netherlands, which resulted in a decline of hepatitis A incidence in children of Turkish and Moroccan descent from 70.3 per 100,000 in 2000 to 13.5 per 100,000 inhabitants in 2005, respectively. 14 Limitations Questionnaire-based surveys may have some drawbacks which may limit the generalization of the current findings. For instance, this study was designed to study the KAP of travelers to destinations with a high or lower risk for hepatitis A, hepatitis B, and malaria and all destinations were selected to meet this requirement. The destinations were not randomly selected from all available risk destinations. Furthermore, the survey was always done in October and November months of each year, which may have introduced a selection bias since people who travel at this time of year may differ from people who travel during summer vacation. Moreover, one could argue that the traveler s KAP profile including those belonging to risk groups may be influenced by their prior travel experience. To specifically address this potential confounder, all questionnaires

9 Trends in KAP of Travel Risk Groups 43 since 2004 contained questions elaborating on this item. Although there were no significant differences in prior travel experience between travelers to high- or low-tointermediate-risk destinations, prior travel experience had in general terms significant effects on protection rate (higher hepatitis A protection rates in those travelers with prior travel experience, p = 0.003) and attitude (more intended risk-taking behavior in travelers with prior travel experience, p < 0.001) but not on the knowledge of travelers. As a result, these (opposite) effects may cancel each other out and thus minimize the impact of this potential confounder. Another limitation of this study may be the use of CDC maps in which high risk countries are separated from intermediate risk countries instead of the WHO maps, which combines intermediate-risk and high-risk countries. As a consequence, in our study, eg, Turkey was categorized as a low-to-intermediate-risk country, whereas it was an important provider of cases of imported hepatitis A, at least in the Dutch setting. 15 Lastly, not all respondents belonged mutually exclusively to one risk group; this may limit the effect attributed to a certain risk profile. However, to keep the analysis straightforward and clear, we did not correct for these effects. In conclusion, the results of this questionnaire-based survey suggest that protection rates of Dutch travelers against hepatitis A increase every year in concert with a slight annual reduction in intended risk-seeking behavior. Travelers VFR and solo as well as last-minute travelers to high-risk destinations were identified as the risk groups with the highest increase in relative risk for hepatitis A. These specific risk groups should be considered candidates for targeted interventions. Acknowledgments This study was done with financial and logistic support from GlaxoSmithKline. Mr Michiel Vervoort is acknowledged for construction of the figure. Ms Kimberley Spong is acknowledged for English textediting. Members of the Dutch Schiphol Airport Study Group are: P. J. J. v G., MD, PhD (Havenziekenhuis, Rotterdam); P. G. H. M., MSc, PhD (Erasmus University, Rotterdam); Christian Hoebe, MD, PhD (GGD, Maastricht); Sietse Felix, MD (KLM Health Services, Amsterdam); P. P. A. M. v T., MD, PhD (Academic Medical Center, Amsterdam), and D. O., MD, PhD (Travel Clinic Havenziekenhuis, Rotterdam). Declaration of Interests P. J. J. v G. has received speaker s fee and reimbursements from GlaxoSmithKline for attending symposia. D. O. has received speaker s fee and reimbursements for attending symposia from GlaxoSmithKline and Sanofi Pasteur MSD. Other authors state they have no conflicts of interest to declare. References 1. Jacobsen KH, Wiersma ST. Hepatitis A virus seroprevalence by age and world region, 1990 and Vaccine 2010; 28: Mutsch M, Spicher VM, Gut C, Steffen R. Hepatitis A virus infections in travelers, Clin Infect Dis 2006; 42: Askling HH, Rombo L, Andersson Y, et al. Hepatitis A risk in travelers. J Travel Med 2009; 16: Boggild AK, Castelli F, Gautret P, et al. Vaccine preventable diseases in returned international travelers: results from the GeoSentinel Surveillance Network. Vaccine 2010; 28: Petrignani M, Harms M, Verhoef L, et al. Update: a foodborne outbreak of hepatitis A in the Netherlands related to semi-dried tomatoes in oil, January February Euro Surveill 2010; 15:pii= van Gorkom J, Leentvaar-Kuijpers A, Kool JL, Coutinho RA. Annual epidemics of hepatitis A in four large cities related to holiday travel among immigrant children. Ned Tijdschr Geneeskd 1998; 142: Van Herck K, Zuckerman J, Castelli F, et al. for the European Travel Health Advisory Board. Travelers knowledge, attitudes, and practices on prevention of infectious diseases: results from a pilot study. J Travel Med 2003; 10: Van Herck K, Castelli F, Zuckerman J, et al. Knowledge, attitudes and practices in travel-related infectious diseases: the European Airport Survey. J Travel Med 2004; 11: Centers for Disease Control and Prevention. CDC health information for international travel. New York: Oxford University Press, Baaten GG, Sonder GJB, Schim van der Loeff MF, et al. Fecal-orally transmitted diseases among travelers are decreasing due to better hygienic standards at travel destination. J Travel Med 2010; 17: Verhoef L, Boot HJ, Koopmans M, et al. Changing risk profile of hepatitis A in the Netherlands: a comparison of seroprevalence in and Epidemiol Infect 2011; 13: Dijkshoorn H, Schilthuis HJ, van den Hoek JA, Verhoeff AP. Travel advice on the prevention of infectious diseases insufficiently obtained by indigenous and non-native inhabitants of Amsterdam, the Netherlands. Ned Tijdschr Geneeskd 2003; 147: Richardus JH, Vos D, Veldhuijzen IK, Groen J. Seroprevalence of hepatitis A virus antibodies in Turkish and Moroccan children in Rotterdam. J Med Virol 2004; 72: Suijkerbuijk AWM, Lindeboom R, van Steenbergen JE, et al. Effect of hepatitis A vaccination programs for migrant children on the incidence of hepatitis A in the Netherlands. Eur J Public Health 2009; 19: Van Der Eerden LJ, Bosman A, Van Duynhoven YT. Surveillance of hepatitis A in the Netherlands Ned Tijdschr Geneeskd 2004; 148: