Travelers' health problems and behavior: prospective study with post-travel follow-up.

BACKGROUND: The annual number of international tourist arrivals has recently exceeded one billion, yet surprisingly few studies have characterized travelers' behavior, illness, and risk factors in a prospective setting. Particularly scarce are surveys of data spanning travel, return, and follow-up of the same cohort. This study examines behavior and illness among travelers while abroad, after return home, and at follow-up. Patterns of behavior connected to type of travel and illness are characterized so as to identify risk factors and provide background data for pre-travel advice. METHODS: Volunteers to this prospective cohort study were recruited at visits to a travel clinic prior to departure. Data on the subjects' health and behavior were collected by questionnaires before and after journeys and over a three-week follow-up. In addition, the subjects were asked to fill in health diaries while traveling. RESULTS: The final study population consisted of 460 subjects, 79 % of whom reported illness during travel or on arrival: 69 % had travelers' diarrhea (TD), 17 % skin problems, 17 % fever, 12 % vomiting, 8 % respiratory tract infection, 4 % urinary tract infection, 2 % ear infection, 4 % gastrointestinal complaints other than TD or vomiting, and 4 % other symptoms. Of all subjects, 10 % consulted a doctor and 0.7 % were hospitalized; 18 % took antimicrobials, with TD as the most common indication (64 %). Ongoing symptoms were reported by 25 % of all travelers upon return home. During the three-week follow-up (return rate 51 %), 32 % of respondents developed new-onset symptoms, 20 % visited a doctor and 1.7 % were hospitalized. Factors predisposing to health problems were identified by multivariable analysis: certain regions (Southern Asia, South-Eastern Asia, and Eastern Africa), female gender, young age, and long travel duration. CONCLUSIONS: Despite proper preventive measures like vaccinations, malaria prophylaxis, and travel advice, the majority of our subjects fell ill during or after travel. As the symptoms mostly remained mild, health care services were seldom needed. Typical traveler profiles were identified, thereby providing a tool for pre-travel advice. The finding that one third reported new-onset illness during follow-up attests to the importance of advising clients on potential post-travel health problems already during pre-travel visits.

Antimicrobials increase travelers' risk of colonization by extended-spectrum betalactamase-producing Enterobacteriaceae.

BACKGROUND: More than 300 million travelers visit regions with poor hygiene annually. A significant percentage of them become colonized by resistant intestinal bacteria such as extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) and may transmit the strains to others and to medical care settings when they return home. Despite the threats to global healthcare caused by an upsurge in antimicrobial resistance, no effort has been centered on prevention of colonization while traveling. METHODS: Stool samples were collected from 430 Finns before and after traveling outside Scandinavia. All specimens were analyzed for ESBL- and carbapenemase-producing Enterobacteriaceae (CPE). Questionnaires were used to survey volunteers about use of antimicrobials as well as other potential risk factors. The results were subjected to multivariable analysis. RESULTS: Twenty-one percent (90/430) of the travelers became colonized by ESBL-PE and none by CPE. Geographic region, occurrence of travelers' diarrhea (TD), age, and use of antimicrobial (AB) for TD were identified as independent risk factors predisposing to contracting ESBL-PE. Eleven percent of those in subgroup TD-AB-, 21% in TD+AB-, and 37% in TD+AB+ acquired ESBL-PE. The risk proved to be highest in South Asia (46%); 23% became colonized in subgroup TD-AB-, 47% in TD+AB-, and 80% in TD+AB+. In Southeast Asia, the rates were 14%, 37%, and 69%, respectively. CONCLUSIONS: TD and antimicrobials for TD proved to be independent risk factors, with up to 80% of TD+AB+ travelers contracting ESBL-PE. In modern pre-travel counseling for those visiting high-risk regions, travelers should be advised against taking antibiotics for mild or moderate TD.

Stand-by antibiotics encourage unwarranted use of antibiotics for travelers' diarrhea: A prospective study.

BACKGROUND: As antibiotics predispose travelers to acquiring multidrug-resistant intestinal bacteria, they should no longer be considered a mainstay for treating travelers' diarrhea. It has been claimed that stand-by antibiotics are justified as a means to avoid visits to local healthcare providers which often lead to polypharmacy. METHOD: We revisited the traveler data of 316 prospectively recruited volunteers with travelers' diarrhea by retrieving from questionnaires and health diaries information on antibiotic use, stand-by antibiotic carriage, and visits with local healthcare. Multivariable analysis was applied to identify factors associated with antibiotic use. RESULTS: Among our 316 volunteers with travelers' diarrhea, however, carrying stand-by antibiotics seemed not to reduce the rate of healthcare-seeking; on the contrary, antibiotic use was more frequent among stand-by antibiotic carriers (34%) than non-carriers (11%). Antibiotics were equally taken for severe and incapacitating travelers' diarrhea, but compared to non-carriers, stand-by antibiotic carriers resorted to medication also for mild/moderate (38% vs. 4%) and non-incapacitating disease (29% vs. 5%). Antibiotic use was associated with stand-by antibiotic carriage (OR 7.2; 95%CI 2.8-18.8), vomiting (OR 3.5; 95%CI 1.3-9.5), incapacitating diarrhea (OR 3.6; 95%CI 1.3-9.8), age (OR 1.03; 95%CI 1.00-1.05), and healthcare visit for diarrhea (OR 465.3; 95%CI 22.5-9633.6). CONCLUSIONS: Carriage of stand-by antibiotics encouraged less cautious use of antibiotics. Recommendations involving prescription of antibiotics for all travelers require urgent revision.

Despite antibiotic treatment of travellers' diarrhoea, pathogens are found in stools from half of travellers at return.

BACKGROUND: Among visitors to the (sub)tropics, 20-50% contract travellers' diarrhoea (TD) and 5-30% take antibiotics. While shortening the duration of illness, antimicrobials predispose to acquisition of multi-drug resistant bacteria. Therefore, liberal use is no longer advocated. Although antibiotics kill pathogens, no data support the view that they could prevent post-infectious sequelae. We investigated how antibiotic use for TD abroad impacts the pathogen findings at return. MATERIALS AND METHODS: We revisited 456 travellers' clinical data and stool pathogens examined by qPCR for Salmonella, Yersinia, Campylobacter, Shigella, Vibrio cholerae and enteroaggregative (EAEC), enteropathogenic (EPEC), enterotoxigenic (ETEC), enterohaemorrhagic (EHEC) and enteroinvasive (EIEC) Escherichia coli. RESULTS: Among travellers with TD, antibiotic users had pathogen-positive samples less frequently than non-users (50% versus 83%). The difference was significant for EPEC (23% versus 47%) and EAEC (27% versus 54%), but not ETEC (17% versus 26%) or the other pathogens. Shigella/EIEC was found more often among antibiotic users than non-users (4% versus 1%). CONCLUSION: Despite antibiotic treatment of TD, half of the users still had stool pathogens at return, reflecting either antibiotic resistance of pathogens or recolonisation/reinfection while abroad. Treatment of TD with antibiotics during travel should not be interpreted to indicate eradication of pathogens.