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ORIGINAL ARTICLES

Travelers’ Preferences for the Treatment and Prevention of Acute Diarrhea Charles D. Ericsson, MD,* Nicolas A. Melgarejo, MD,* Tomas Jelinek, MD,† Anne McCarthy, MD,‡ and the International Society of Travel Medicine Clinical Research Group1 *Department of Medicine, Division of Infectious Diseases, University of Texas Medical School at Houston, Houston, TX, USA; † Berlin Center for Travel and Tropical Medicine, Berlin, Germany; ‡Ottawa Hospital, Ottawa, Canada DOI: 10.1111/j.1708-8305.2009.00317.x

Background. A survey was designed to assess travelers’ willingness to take antibiotic chemoprophylaxis against travelers’ diarrhea (TD) or to intervene with antibiotic or symptomatic treatments. Methods. A brief written questionnaire was administered to clients in North American (United States and Canadian) and European (UK and German) travel clinic waiting rooms to assess length, purpose, and destination of their upcoming trips; their perceived risk of developing TD at their destination; and their preferences for hypothetical treatment or chemoprophylaxis options, which included descriptions, but no mention of brand names, of a systemically absorbed antibiotic based on a fluoroquinolone, a nonabsorbed antibiotic based on rifaximin, and an over-the-counter antidiarrheal similar to loperamide. Results. The 209 UK and German travelers planned significantly longer travel than the 277 US and Canadian travelers (25 vs 15 d, p < 0.001) and correctly recognized high risk of TD more often than the North Americans (81% vs 61%, p < 0.001). More of the North Americans preferred any therapy options compared with the Europeans; only 14% of the North Americans preferred no treatment compared with 29% of the Europeans (p < 0.001). More of the North Americans and the Europeans preferred the nonabsorbed antibiotic than the systemically absorbed antibiotic, regardless of if combined with the antidiarrheal agent. Significantly more of the Europeans preferred not to take antibiotic chemoprophylaxis than North Americans (66% vs 37%, p < 0.001). Among the North Americans, significantly more travelers preferred chemoprophylaxis with the nonabsorbed than the systemic antibiotic (45% vs 33%, p = 0.003). Conclusions. Among the relatively small groups of travelers studied, the UK and German travelers were more cognizant of TD risk than US and Canadian travelers. The Europeans were less inclined to take chemoprophylaxis or treatment. Both groups preferred treatment or prophylaxis with the nonabsorbed antibiotic over the systemically absorbed antibiotic or the antidiarrheal agent.

D

iarrheal illness is the most common ailment affecting international travelers,1 with reported incidence of up to approximately 60% among individuals who traveled to developing regions.1,2 Infection with bacterial pathogens is the primary cause of travelers’ diarrhea (TD), accounting for approximately 80% of cases.3,4 The risk of developing TD depends primarily on destination 1

Fiona Genasi, Heather M. Gilmartin, John D. Hall, Suzanne Hall, Nyala Ndebele, Carol Singer, Alan Spira, and Jane Zuckerman. Abstract presented at 10th Conference of the International Society of Travel Medicine, May 20-24, 2007, Vancouver, British Columbia, Canada. Corresponding Author: Charles D. Ericsson, MD, Department of Medicine, Division of Infectious Diseases, University of Texas Medical School at Houston, 2.112 MSB, 6432 Fannin Street, Houston, TX 77030, USA. E-mail: charles.d.ericsson@ uth.tmc.edu © 2009 International Society of Travel Medicine, 1195-1982 Journal of Travel Medicine 2009; Volume 16 (Issue 3): 172–178

and origin of travel, with travelers from industrialized regions who visit developing or tropical regions having the highest risk.4,5 Travelers’ characteristics, such as age, use of proton pump inhibitors, and genetic factors, may also increase risk of diarrheal illness.4,5 Although TD is usually self-limiting and resolves within several days, symptoms may persist for weeks or months for some patients and may lead to chronic conditions, such as irritable bowel syndrome.3,4,6 To prevent diarrhea, most travelers are advised to avoid consuming certain foods and beverages.3,4 However, obtaining such advice before travel does not appear to reduce the risk of developing diarrhea.2,4,7,8 As many as 59% of travelers to high-risk regions have reported developing diarrheal illness despite having received pretravel health counseling2,7 and up to 79% of travelers admitted noncompliance with dietary recommendations.8,9 In contrast to TD education as a preventative measure, antibiotic chemoprophylaxis has been shown to be effective in

Travelers’ Preferences for Diarrheal Treatments and Prophylaxis randomized, placebo-controlled studies,10–13 but use of prophylaxis remains highly controversial and has not become routine practice.4,14 Prophylaxis with the fluoroquinolones ciprofloxacin or norfloxacin provided a 77% to 94% protection rate among travelers to high-risk regions (p < 0.0001 vs placebo).10,11 Likewise, the nonabsorbed (75%). Participants planning travel to developing regions who indicated >25% perceived TD risk were considered to appropriately recognize their risk of developing TD. The second section of the questionnaire assessed participants’ willingness to take specific oral TD agents, without specifying product names, by asking them to indicate on a 5-point Likert scale how likely they would be (ie, very unlikely, somewhat unlikely, uncertain, somewhat likely, or very likely) to take each of several options for diarrheal treatment and prophylaxis. Participants who indicated they were somewhat likely or very likely to take a therapeutic or prophylactic option were considered to prefer that option. The hypothetical medications described in the questionnaire included an OTC antidiarrheal agent based on loperamide, a systemic antibiotic (antibiotic A) based on a fluoroquinolone, and a nonabsorbed antibiotic (antibiotic B) based on rifaximin. The questionnaire included a brief, general introduction about TD prophylaxis and standard treatment, along with several assumptions. Participants were to assume that their doctor would make available to them any advice or prescriptions listed in the questionnaire table and that they were at moderate-tohigh risk of developing TD. For treatment of diarrhea, six options were described: the OTC antidiarrheal agent, the systemic antibiotic (antibiotic A), the nonabsorbed antibiotic (antibiotic B), a combination of the antidiarrheal agent plus antibiotic A, a combination of the antidiarrheal agent plus antibiotic B, and no treatment medication. Participants were to assume the following information about the TD medications described in the questionnaire. The OTC antidiarrheal agent had an excellent safety record; it would relieve symptoms quickly but would not cure diarrhea, so that symptoms might recur over several days and require repeated doses of OTC medication to control symptoms while the illness cured itself. No mention was made of the need for some patients to add an antibiotic if symptoms failed to adequately improve with the OTC medication. Antibiotic A was absorbed from the gastrointestinal tract into the bloodstream; it could cause mild-to-moderate, reversible adverse effects (eg, upset stomach, rash) in approximately 1% to 3% of patients but rarely caused serious adverse effects. Antibiotic A would cure diarrhea, so that after about 24 hours, symptoms would not recur. Antibiotic B was a new antibiotic that was not absorbed from the gastrointestinal tract into the bloodstream; it could J Travel Med 2009; 16: 172–178

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uncommonly cause mild stomach upset, which was its only recognized adverse effect. It also would cure diarrhea, so that after about 24 hours, symptoms would not recur. The OTC antidiarrheal agent with either antibiotic A or B would control symptoms quickly and cure the diarrhea, so that after 4 to 6 hours, symptoms would not recur. The dosing regimens for treatment with the OTC and antibiotics A and B were not specified. Three options for TD prophylaxis were described as follows: a single daily dose of either antibiotic A or antibiotic B or no prophylactic medication. Both antibiotics were described as being able to prevent about 80% of TD cases. Diarrhea that occurred despite prophylaxis would be treated as the client and doctor decided. Statistical analyses of this descriptive study of perception differences included chi-square testing to compare characteristics of the North American travelers with the European travelers and to compare their preferences for TD treatment or chemoprophylaxis. The study was powered to detect at least a 15% difference in preferences at a power of 0.8 with significance defined as p < 0.05. Because the study was not designed to explore the behavioral or other causes for preference differences, a multivariate analysis was not performed. This study was approved by the Committee for the Protection of Human Subjects at The University of Texas Health Science Center at Houston in Texas. All participating researchers were authorized by their own institutions to enroll humans in clinical studies. Results A total of 486 individuals completed questionnaires and were included in the analyses (Table 1); 235 (48%) were from the United States, 42 (9%) were from Canada, Table 1

97 (20%) were from the UK, and 112 (23%) were from Germany. Because no significant demographic differences between United States and Canadian or UK and German travelers were observed, data were pooled by continent of origin into North American and European groups. The percentage of participants planning travel for business was significantly higher in the North American group compared with the European group (17% vs 9%, respectively, p = 0.02; Table 1). The percentage of the European respondents planning leisure travel was slightly higher compared with the North American respondents (51% vs 48%, respectively), however, this difference was not significant (Table 1). Within the North American group, the median duration of leisure travel was similar for Canadian travelers compared with US travelers (16 vs 14 d), but Canadian travelers reported longer travel duration overall due to longer travel for business, visiting family and friends, or other reasons (p < 0.05 for each comparison). Overall, the European participants planned travel for longer periods compared with travelers from North America (25 vs 15 d, respectively, p < 0.001) for leisure (p < 0.001) and for other reasons (p < 0.001; Table 1). Of the travelers who were planning trips to developing regions, a significantly higher percentage of the Europeans correctly indicated that they were at high risk (>25%) for developing TD while at their destination compared with participants from North America traveling to similar destinations (81% vs 61%, p < 0.001). Among travelers from North America, 55% to 66% of participants favored one TD treatment or another, whereas 39% to 52% of travelers from Europe preferred one or another form of treatment. Significantly more travelers from North America preferred each medication option compared with the European travelers (Figure 1).

Participant demographics and travel characteristics based on origin of travel

Mean age (range), y Female, % Reason for travel, % Leisure Business Visit family/friends Other No response Planning travel to developing region, % Median duration of travel (range), d All Leisure Business Visit family/friends Other With duration (wk) of leisure travel, % ≤2 >2 and ≤4 >4 No response

North America* (n = 277)

Europe† (n = 209)

p Value

40 (15–82) 53

35 (15–79) 48

NS NS

48 17 5 20 10 95

51 9 9 24 7 76

NS 0.02 NS NS NS