Risk Behavior for Travelers' Diarrhea Among Finnish Travelers

Revisiting travellers' diarrhoea justifying antibiotic treatment: prospective study

BACKGROUND

As antimicrobials increase the risk of acquiring multidrug-resistant (MDR) bacteria, unnecessary antibiotics should be avoided for travellers' diarrhoea (TD). Antibiotics are recommended in TD accompanied by fever or incapacitation (TD justifying use of antibiotics, TDjuAB). Seeking tools for reducing antibiotic use, we explored factors predisposing to TDjuAB and scrutinized antibiotic treatment among those with TDjuAB [TDjuAB(+) subgroup] and those with diarrhoea not justifying antibiotics [TDjuAB(-) subgroup].

METHODS

We conducted a study among 370 prospectively recruited visitors to the tropics. Stool samples and questionnaires were collected before and after travel. Enteric pathogens were analysed by qPCR for enteropathogenic (EPEC), enteroaggregative (EAEC), enterotoxigenic (ETEC), enterohaemorrhagic (EHEC) and enteroinvasive (EIEC) E. coli/Shigella, Campylobacter, Salmonella, Yersinia and Vibrio cholerae, and for ETEC's toxins LT (heat-labile), STh (human heat-stable) and STp (porcine heat-stable). TD was defined by the WHO criteria and TDjuAB as diarrhoea accompanied by fever, and/or disrupting or preventing daily activities. Multivariable analysis was applied-separately for travel-related factors and pathogens-to identify risk factors for TDjuAB(+).

RESULTS

Among the 370 travellers, TD was contracted by 253 (68%), categorized as TDjuAB(+) in 93/253 (37%) and TDjuAB(-) in 160/253 (63%) of the cases. Antibiotics were used for TD by 41% in TDjuAB(+) and by 7% in the TDjuAB(-) group. Relative risk ratios (RRR)s are presented for both the TDjuAB(+) and the TDjuAB(-) groups. TDjuAB(+) was associated with long travel duration and young age. Among the 298 subjects not having taken antibiotics, increased RRRs were found e.g. for findings of Campylobacter coli/jejuni and ETEC's STh toxin.

CONCLUSIONS

The first to analyse risk factors for TDjuAB, our study presents RRRs for demographic and behavioural factors and for various pathogens. Only less than half of those in the TDjuAB(+) group took antibiotics, which demonstrates that most cases meeting the current criteria recover without antimicrobial treatment.

Doxycycline Malaria Prophylaxis Impact on Risk of Travelers' Diarrhea among International Travelers

International travelers are frequently at risk for travelers' diarrhea (TD) and malaria. Doxycycline was one of the earliest antibiotics shown to have efficacy in TD prevention. With increasing resistance and recommendations against antibiotic chemoprophylaxis, doxycycline fell out of use. We evaluated TD incidence and risk factors in a prospective cohort of travelers, specifically in regard to malaria prophylaxis. Travelers' diarrhea was defined as ≥ 3 loose stools in 24 hours or two loose stools in 24 hours associated with other gastrointestinal symptoms. The Poisson regression model with robust error variance was used to estimate the RR of TD. Three thousand two hundred twenty-seven trips were enrolled: 62.1% of participants were male, with a median age of 39 years (interquartile range [IQR] 27,59) and a median travel duration of 19 days (IQR 12,49); 17.4% developed TD; 32% traveled to Africa, 40% to Asia, and 27% to the Caribbean and Latin America; and 20% took doxycycline for malaria chemoprophylaxis, 50% took other antimalarials, and 30% took none. Decreased RR of TD was associated with doxycycline (RR 0.62 [0.47-0.82], P < 0.01) and military travel (RR 0.57 [0.47-0.70], P < 0.01). Increased risk of TD was associated with female gender (RR 1.28 [1.09-1.50], P < 0.01), hotel accommodations (RR 1.30 [1.10-1.53], P < 0.01), travel to tropical South America (RR 1.34 [1.09-1.64], P < 0.01), and duration of travel (RR 1.00 [1.00-1.01], P < 0.01). The use of doxycycline for malaria prophylaxis is associated with lower TD risk, suggesting increasing bacterial enteropathogen susceptibility similar to previous observations. Doxycycline selection for antimalarial chemoprophylaxis may provide additional traveler benefit in infection prevention.

An assessment of household water quality among Peace Corps volunteers in Guatemala

Background

Gastrointestinal (GI) illness is the most commonly reported health concern among Peace Corps Volunteers (PCVs) serving in Guatemala. This project identified water types and treatment and storage practices used by PCVs and measured select water quality parameters in their household water.

Methods

A survey about water types and practices was conducted of PCVs in Guatemala. The water type most frequently consumed in the household ("primary drinking water") and other water types present in the household ("secondary water") were tested for free chlorine residual (FCR) and for the presence of Escherichia coli and total coliforms. A negative binomial regression model was used to analyze data on incidence of self-reported GI illness.

Results

Tambo (commercially purified water in a 5-gal bottle) was the water type most frequently (64%) reported as primary drinking water in 39 PCV households. Most (74%) PCVs reported drinking water other than primary drinking water ≥1 day per week; the incidence rate of GI illness per PCV per month was significantly lower among PCVs who reported never consuming water other than primary drinking water compared to those who did (0.4 and 1.6 GI illnesses per PCV per month, respectively) (p < 0.05). E. coli was not detected in any primary drinking water sample, but was detected in 35% of secondary water samples. Total coliforms were detected in more than two-thirds of primary drinking water and secondary water samples. Nearly all water samples had an FCR of < 0.2 mg/L.

Conclusions

Consuming primary drinking water exclusively likely contributes to reducing the rate of GI illness among PCVs. However, most PCVs reported drinking multiple water types, which may include contaminated secondary water types in the household. All water intended for consumption, including secondary sources within and outside the household, should be properly treated and safely stored.

Travellers' diarrhoea: Impact of TD definition and control group design on study results

BACKGROUND

Travellers' diarrhoea (TD) is a common health problem among visitors to the (sub)tropics. Much research deals with aetiology, prevention, and post-infection sequalae, yet the data may not allow comparisons due to incompatible definitions of TD and No TD control groups.

METHOD

The impact of defining TD and No TD control groups was explored by revisiting our recent data. We set up two TD groups: classical TD i.e. ≥3 loose or liquid stools/day and WHO TD (diarrhoea as defined by the WHO) i.e. any diarrhoea, and four No TD groups by TD definition and timing (no classical/WHO TD during travel, no ongoing classical/WHO TD).

RESULTS

TD was recorded for 37% versus 65% of subjects when using classical versus WHO definitions, respectively; the proportions of the various pathogens proved similar. The strictest criterion for the No TD control group (no WHO TD during travel) yielded pathogens among 61% and the least strict (no ongoing classical TD) among 73% of the travellers; the differences were greatest for enteroaggregative Escherichia coli and Campylobacter.

CONCLUSIONS

Definition of TD and control group design substantially impact on TD study results. The WHO definition yields more cases, but the pathogen selection is similar by both definitions. Design of the No TD control group was found critical: only those remaining asymptomatic throughout the journey should be included.

Travel-acquired ESBL-producing Enterobacteriaceae: impact of colonization at individual and community level

BACKGROUND

Antibiotic resistance is a rapidly increasing global emergency that calls for action from all of society. Intestinal multidrugresistant (MDR) bacteria have spread worldwide with extended-spectrum beta-lactamase (ESBL) -producing Enterobacteriaceae (ESBL-PE) as the most prevalent type. The millions of travelers annually visiting regions with poor hygiene contribute substantially to this spread. Our review explores the underlying data and discusses the consequences of the colonization.

METHODS

PubMed was searched for relevant literature between January 2010 and August 2016. We focused on articles reporting (1) the rate of ESBL-PE acquisition in a group of travelers recruited before/after international travel, (2) fecal carriage of ESBL-PE as explored by culture and, for part of the studies, (3) analysis of factors predisposing to colonization.

RESULTS

We reviewed a total of 16 studies focusing on travel-acquired ESBL-PE. The acquisition rates reveal that 2070% of visitors to (sub)tropical regions get colonized by ESBL-PE. The main risk factors predisposing to colonization during travel are destination, travelers diarrhea, and antibiotic use.

CONCLUSIONS

While most of those colonized remain asymptomatic, acquisition of ESBL-PE may have consequences both at individual and community level. We discuss current efforts to restrict the spread.

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.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1682-0) contains supplementary material, which is available to authorized users.

Summary of the Committee to Advise on Tropical Medicine and Travel (CATMAT) Statement on Travellers' Diarrhea

Background

Most travellers' diarrhea (TD) infections occur during travel to low- and middle-income countries. Type of travel, duration of stay, age of traveller and presence of certain medical conditions are important factors to consider for risk of TD. The Committee to Advise on Tropical Medicine and Travel (CATMAT) assembled a TD working group to develop recommendations on prevention and treatment of TD in travellers. This document is a summary of the Statement on Travellers' Diarrhea.

Methods

Following a systematic review of the literature, recommendations on the prevention and treatment of TD were developed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology to evaluate data quality, benefits and harms of the intervention, and values and preferences of the traveller. Other recommendations were based on a review of the literature and expert opinion.

Recommendations

Using the GRADE methodology, CATMAT concluded that oral cholera vaccine should not be routinely recommended to prevent TD in Canadian travellers. This recommendation was based on moderate quality data that showed this vaccine was not effective in preventing TD in travellers compared to placebo. Bismuth subsalicylate (BSS), fluoroquinolones or rifaximin are options for the prevention of TD based on high-quality data for BSS and fluoroquinolones and moderate evidence for rifaximin. For the treatment of TD, loperamide (alone or in combination with antibiotics), fluoroquinolones, azithromycin and rifaximin are all options, with varying degrees of data quality. Based on available evidence and expert opinion, CATMAT recommends handwashing or the use of hand sanitizer, as well as prudent choice and preparation of food and beverages as best practices for preventing diarrhea while travelling. At this time, a recommendation cannot be made for either the use of probiotics and prebiotics to prevent TD or the use of BSS to treat TD due to insufficient available evidence.

Conclusion

With the exception of BSS for prevention of TD (strong recommendation for use), CATMAT conditionally recommends the use of each of the other GRADE-evaluated preventive and therapeutic products assessed in this Statement. These CATMAT recommendations should be considered as options in the prevention and treatment of TD based on the particular situation of the traveller.

Epidemiology and self-treatment of travelers' diarrhea in a large, prospective cohort of department of defense beneficiaries

BACKGROUND

Infectious diarrhea is a common problem among travelers. Expert guidelines recommend the prompt use of antibiotics for self-treatment of moderate or severe travelers' diarrhea (TD). There is limited data on whether travelers follow these self-treatment guidelines. We evaluated the risk factors associated with TD, the use of TD self-treatment, and the risk of irritable bowel syndrome (IBS) during travel.

METHODS

Department of Defense beneficiaries traveling outside the United States for ≤6.5 months were enrolled in a prospective cohort study. Participants received pre- and post-travel surveys, and could opt into a travel illness diary and follow-up surveys for symptoms of IBS. Standard definitions were used to assess for TD and IBS. Suboptimal self-treatment was defined as the use of antibiotics (with or without antidiarrheal agents) for mild TD, or the use of antidiarrheals alone or no self-treatment in cases of moderate or severe TD.

RESULTS

Twenty-four percent of participants (270/1,120) met the criteria for TD. The highest incidence was recorded in Africa [8.6 cases/100 person-weeks, 95% confidence interval (CI): 6.7-10.5]. Two hundred and twelve participants with TD provided information regarding severity and self-treatment: 89 (42%) had mild TD and 123 (58%) had moderate or severe TD. Moderate or severe TD was independently associated with suboptimal self-treatment [OR 10.4 (95% CI: 4.92-22.0)]. Time to last unformed stool did not differ between optimal and suboptimal self-treatment. IBS occurred in 4.5% (7/154) of TD cases and in 3.1% (16/516) of cases without TD (p = 0.39). Among TD cases, a lower incidence of IBS was noted in participants who took antibiotics [4.8% (5/105) vs 2.2% (1/46)] in those who did not, but the difference did not reach statistical significance (p = 0.60).

CONCLUSIONS

Our results suggest the underutilization of antibiotics in travelers with moderate or severe TD. Further studies are needed to systematically evaluate pre-travel instruction and traveler adherence to self-treatment guidelines, and the impact of suboptimal self-treatment on outcomes.

High number of diarrhoeal co-infections in travellers to Benin, West Africa

Background

Travellers’ diarrhoea (TD) is the most frequent health problem among travellers to the tropics. Using routine techniques, the aetiology mostly remains unresolved, whereas modern molecular methods enable reducing the number of equivocal cases considerably. While many studies address the aetiology of TD in Asian, Central American and North African tourist resorts, only few focus on Western Africa.

Methods

Stool samples from 45 travellers travelling in Benin, West Africa, were analyzed by a new multiplex qPCR assay for Salmonella, Yersinia, Campylobacter, Vibrio cholerae, Shigella or enteroinvasive (EIEC), enterohaemorrhagic (EHEC), enterotoxigenic (ETEC), enteroaggregative (EAEC), and enteropathogenic Escherichia coli (EPEC).

Results

All 18 pre-travel samples proved negative for bacterial pathogens. Of the 39/45 (87%) travellers having had TD, EPEC was detected in post-travel samples in 30 (77%) cases, EAEC in 23 (59%), ETEC in 22 (56%), Shigella or EIEC in 7 (18%), EHEC in two (5%), and Salmonella in one (3%). In 31(79%) of the TD cases two or more bacterial pathogens were identified. Two (8%) samples remained negative: both patients had taken antimicrobials for TD.

Conclusions

EPEC, EAEC and ETEC were the most common findings. 79% of the cases had a co-infection. As modern diagnostics reveals in most patients a multitude of pathogens, the role of each pathogen should be re-evaluated.

Incidence and impact of travelers' diarrhea among foreign backpackers in Southeast Asia: a result from Khao San road, Bangkok

BACKGROUND

Travelers' diarrhea is the most common disease reported among travelers visiting developing countries, including Southeast Asia, a region visited by large numbers of backpackers each year. Currently, the knowledge of travelers' diarrhea among this group is limited. This study aimed to determine the incidence and impact of travelers' diarrhea in this group.

METHOD

Foreign backpackers in Khao San road, Bangkok, Thailand, were invited to fill out a study questionnaire, in which they were queried about their demographic background, travel characteristics, pretravel preparations and actual practices related to the risk of travelers' diarrhea. For backpackers who had experienced diarrhea, the details and impact of each diarrheal episode were also assessed.

RESULTS

In the period April to May 2009, 404 completed questionnaires were collected and analyzed. Sixty percent of participants were male; overall, the median age was 26 years. Nearly all backpackers (96.8%) came from developed countries. Their main reason for travel was tourism (88%). The median stay was 30 days. More than half of the backpackers (56%) carried some antidiarrheal medication. Antimotility drugs were the most common medications carried by backpackers, followed by oral rehydration salts (ORS), and antibiotics. Their practices were far from ideal; 93.9% had bought food from street vendors, 92.5% had drunk beverages with ice-cubes, and 33.8% had eaten leftover food from a previous meal. In this study, 30.7% (124/404) of backpackers had experienced diarrhea during their trip. Most diarrhea cases (88%) were mild and recovered spontaneously. However, 8.8% of cases required a visit to a doctor, and 3.2% needed hospitalization. Longer duration of stay and drinking beverages with ice-cubes were associated with higher risk of diarrhea.

CONCLUSIONS

About one third of the foreign backpackers in Southeast Asia had experienced diarrhea during their trip. Their current practices related to the risk of travelers' diarrhea were inadequate and should be improved.

Description of the food safety system in hotels and how it compares with HACCP standards

BACKGROUND

Tourism is an important earner of foreign exchange in Jamaica; hence, the protection of the visitors' health is very important. A study of travelers to Jamaica in 1996 to 1997 found that travelers' diarrhea (TD) affected almost 25% of visitors. The Ministry of Health (Jamaica) initiated a program for the prevention and control of TD aimed at reducing attack rates from 25.0% to 12.0% over a 5-year period through environmental health and food safety standards of hotels. This article examines the food safety systems in Jamaican hotels located in a popular resort area to find out how comparable they are with the Hazard Analysis Critical Control Point (HACCP) strategy.

METHODS

A cross-sectional study was done of hotels in St. Mary and St. Ann. Quantitative data were obtained from food and beverage/sanitation staff and qualitative data through in-depth interviews with hotel managers. Observation of the food safety operations was also done.

RESULTS

The majority (75%) of larger hotels used a combination of HACCP and Ministry of Health food safety strategies (p = 0.02) and offered all-inclusive services (r =-0.705, p = 0.001). Larger hotels were more likely to have a better quality team approach, HACCP plan, and monitoring of critical control points (CCPs) and more likely to receive higher scores (p < 0.05). More than two thirds of hotel staff were knowledgeable of HACCP. Significantly smaller hotels (87.5%) received less than 70% in overall score (r = 0.75, p = 0.01). Identification of CCPs and monitoring of CCPs explained 96.6% of the change in the overall HACCP scores (p = 0.001). Hotel managers felt that some hotels' systems were comparable with HACCP and that larger properties were ready for mandatory implementation. Conclusions. While some components of the HACCP system were observed in larger hotels, there were serious shortcomings in its comparison. Mandatory implementation of HACCP would require that sector-specific policies be developed for smaller hotels and implemented on a phased basis.

Traveler's diarrhea: updates for pediatricians

Children who travel are at risk of developing the same illnesses that affect adult travelers. Treatment, etiology and actual risk of TD in children are not well defined. Prevention and self-treatment of TD should be discussed in great detail during pre-travel counseling. This includes information and instructions on various preventive measures as well as when to use medications and the potential adverse effects associated with these medications. A TD that is mild can be managed effectively by appropriate use of oral rehydration solutions. Families should be advised to carry ORS packets and start treatment in children as soon as the diarrhea begins. Self treatment with antibiotics such as azithromycin may be considered in children if diarrhea is moderate to severe. Caregivers should contact local health authorities if there is no improvement especially after self treatment with antibiotics.

Looking for evidence that personal hygiene precautions prevent traveler's diarrhea

In the 50 years during which traveler's diarrhea has been studied, it has always been assumed that personal hygiene precautions can prevent or reduce the likelihood of developing traveler's diarrhea. However, 7 of 8 studies that specifically addressed this issue showed no correlation between the types of food selected and the risk of acquiring traveler's diarrhea. The eighth study showed a correlation between a few dietary mistakes and a decreased risk of acquiring traveler's diarrhea. A further increase in the number of dietary mistakes, however, did not continue to increase the risk of acquiring traveler's diarrhea. Personal hygiene precautions, when performed under the direct supervision of an expatriate operating his or her own kitchen, can prevent traveler's diarrhea, but poor restaurant hygiene in most developing countries continues to create an insurmountable risk of acquiring traveler's diarrhea.

Travelers' compliance to prophylactic measures and behavior during stay abroad: results of a retrospective study of subjects returning to a travel medicine center in Italy

BACKGROUND

Many sources of health advice are consulted by travelers, but in Europe, only 35% go to a travel clinic. Travel to countries outside Europe increases daily, and from 2001 to 2004, there was a marked increase in the number of travelers from the Florentine area crossing the borders (+18.0%), taking a plane (+81.4% of international travelers in Pisa airport), and applying to the Centre of Travel and Migration Medicine (CTMM) (+96%).

METHODS

An anonymous survey was carried out at CTMM among those travelers returning to complete vaccinations for which the first dose had been given before going abroad. The survey included questions on vaccination status, adherence to recommended antimalaria prophylaxis, occurrence of other health problems, and food and drink consumption.

RESULTS

The study population (which represents a "best case scenario") was composed of 1,237 subjects and had a very high compliance to the proposed questionnaire (95%). Approximately 55% of travelers took malaria chemoprophylactic measures, and 88% of them followed the indications given. Approximately 28% reported one or more secondary effects following antimalarial medication, and approximately 69% reported constant attention regarding safe consumption of food and drinks. Notwithstanding these measures, 236 cases of travelers' diarrhea were reported.

CONCLUSIONS

Our results are conditioned by the self-selection of the study population (those who seek advice are likely to follow it through). However, since no certainty exists about other sources of health advice for the remainder of the traveler population in our region, both the importance of counseling offered by travel clinics as well as the recommendation to the ever-increasing number of travelers to consult these clinics are stressed.

Behaviors and perceptions of Japanese tourists affecting diarrheal illness and health care need assessment: A questionnaire study

Objectives

To measure the prevalence rate of, and determine the association between food and drink related behaviors and diarrheal illness among Japanese tourists, and assess their health care needs.

Methods

Eligible Japanese tourists (1,480) aged ≥15 years traveling in Chiangmai Province in the north, Ayutthaya Province in the center, Kanchanaburi Province in the west, Pattaya City in the east, and Krabi Province in the south of Thailand were enrolled in the study. Of these tourists, 1,318 consented to participate in this study and completed questionnaires in Japanese, giving a response rate of 89.1%.

Results

Among these Japanese tourists 21.3% had diarrheal illness, and of these tourists, 5.0% had classical travelers’ diarrhea (TD), 11.8% had mild TD, 3.3% had good food and drink related behaviors, and 75.4% had moderate level of perception of diarrhea related to drinking and eating. Multiple logistic regression analysis indicated three significant diarrheal illness predictors: large number of previous visits to Thailand, longer stay in Thailand, and the experience of visiting other countries. Furthermore, 56.9% suggested providing an adequate number of toilets at tourist destinations; 53.9% suggested providing a 24-hour emergency call facility for a public ambulance; and 51.9% suggested providing garbage bins and garbage disposal facilities at tourist destinations.

Conclusions

TD still affects experienced Japanese tourists who visit Thailand. Although the proportions of the good levels of food and drink related behaviors were low, there were indications that Japanese tourists perceived the risk of contracting TD.

Prevention and self-treatment of traveler's diarrhea

Of the millions who travel from the industrialized world to developing countries every year, between 20% and 50% will develop at least one episode of diarrhea, making it the most common medical ailment afflicting travelers. Although usually a mild illness, traveler's diarrhea can result in significant morbidity and hardship overseas. Precautions can be taken to minimize the risk of developing traveler's diarrhea, either through avoidance of potentially contaminated food or drink or through various prophylactic measures, including both nonpharmacological and antimicrobial strategies. If diarrhea does develop despite the precautions taken, effective treatment-usually a combination of an antibiotic and an antimotility agent-can be brought by the traveler and initiated as soon as symptoms develop. In the future, vaccines-several of which are in the advanced stages of clinical testing-may be added to the list of prophylactic measures.

Diarrhea and respiratory symptoms among travelers to Asia, Africa, and South and Central America from Scotland

Surveillance using admissions to hospital, while being useful, is a poor indicator of the real incidence of disease encountered by travelers. An alternative is self-reported illness among those who attended at a pretravel clinic prior to their travels. Estimates of incidence and risk factors were determined for attendees at a travel clinic in Scotland using a questionnaire. Analysis for risk factors was carried out for those travelers visiting countries in Africa, Asia, or South and Central America, who had traveled for 1 week or more and had returned between 1997 and 2001 (N= 4,856). Multivariate logistic regression was used to test the hypotheses that time abroad and age-group would be significant for both respiratory and diarrheal symptoms regardless of which of the three geographical areas are visited. From 2006 returned questionnaires (response rate = 41.3%), diarrhea and respiratory symptoms were reported by 44.2 and 16.8% of respondents, respectively; the incidence was significantly greater among travelers to Asia for both diarrheal (55.5%) and respiratory (23.7%) symptoms than among travelers to Africa (36.6 and 12.2%, respectively) or South and Central America (39.5 and 16.2%, respectively). For diarrhea, age was a highly significant risk factor for travelers to Asia, South and Central America, and Africa. Being a self-organized tourist/backpacker, traveling to Asia was associated with increased risk, while for Africa and South and Central America visiting family or friends was associated with a lower risk. For travelers to Asia, traveling to the Indian subcontinent was significantly associated with increased risk. The majority of travelers had an adverse event while traveling abroad, with diarrhea and respiratory conditions being especially common despite attending a travel clinic for advice prior to departure. However, the limitations of this surveillance-based strategy have highlighted the requirement for more research to understand more fully the issues of risk and incidence among travelers to high-risk destinations from Scotland.

Oral cholera vaccine—for whom, when, and why?

The search for a safe, effective, well tolerated, low cost vaccine against the ancient cholera enemy has been ongoing since the 19th century and has been revitalized in the past two decades since the advent of recombinant technology. Large-scale field trials have readily demonstrated the tolerability and safety of oral cholera vaccine in various forms. Variable levels of protection have been shown and one challenge has been to demonstrate whether this is a cost effective treatment in differing environments including its use in endemic and epidemic areas as well as for travelers. A review of recent literature was undertaken to assess the effectiveness and uses of currently available oral cholera vaccine. While the evidence does not support the creation of formal guidelines, some clear recommendations can be made. There is undoubtedly the potential to reduce the burden of illness both in endemic and epidemic situations. For travelers, certain higher risk groups may benefit from protection against cholera. More significantly, the short term cross-protection afforded by whole cell, B subunit (WC BS) oral cholera vaccine formulations against enterotoxigenic E. coli, (ETEC), the commonest causative agent of traveler's diarrhoea, may prove to be the most important raison d'être.

Risk and spectrum of diseases in travelers to popular tourist destinations

BACKGROUND

Traveling to tropical regions is related to increased health risks. Travelers' diarrhea is the most frequent health problem, but the range of travel-related diseases also includes potential life-threatening diseases such as malaria. The actual risk of European travelers acquiring specific infectious diseases and other hazards in the tropics is to a large extent unknown and is therefore often adopted from that of the indigenous population. The objective of this study was to elucidate the risk for travel-related diseases, symptoms, and accidents in a population of Europeans who travel to popular tourist destinations.

METHODS

From July 2003 to June 2004, 794 travelers consulting the travel clinic of the Berlin Institute of Tropical Medicine were recruited for a questionnaire-based observational study before traveling to Kenya, Tanzania, Senegal, the Gambia, India, Nepal, Thailand, or Brazil.

RESULTS

Overall, illness was reported by 42.9% of travelers, with 10.2% reporting more than one adverse health event. Most frequently gastrointestinal symptoms were noted (34.6%), followed by respiratory symptoms (13.7%). More than 5% experienced an accident. Travel to the Indian subcontinent nearly doubled the risk of becoming ill; travel to Thailand significantly decreased the risk. Additional risk factors were a long duration of staying abroad, young age, and traveling under basic conditions. Of all travelers, 80% did not follow the traditionally recommended dietary restrictions. Among travelers visiting malaria-endemic areas, 20% did not carry any antimalarial drugs with them, not continuous chemoprophylaxis or standby medication.

CONCLUSIONS

Because of the rising travel activity, especially to tropical countries, the importance of qualified pretravel advice consultation is increasing. To improve the travelers' health, attention needs to be paid to individual risk factors, the prevention and therapy of travelers' diarrhea, malaria prophylaxis, management of respiratory illness, and personal safety.

Correlation between adherence to precautions issued by the WHO and diarrhea among long-term travelers to India

BACKGROUND

Travelers' diarrhea is the most common infectious disease afflicting travelers to developing countries. Most studies investigating the benefits of recommendations regarding the consumption of food and water have focused on short-term travelers. We investigated the benefits of adherence to the precautions from the World Health Organization (WHO) among long-term travelers.

METHODS

We asked 140 incidental travelers in India traveling for at least 2 months to complete a questionnaire about their adherence to the WHO precautions and the occurrence of diarrhea. Adherence was graded on a scale of 1 to 6 (least to most).

RESULTS

The mean age of the 114 travelers whose questionnaires were eligible was 26.6 +/- 5.7 years, and the median duration of their trip was 5 months. None of them adhered strictly to the entire set of rules. The mean individual adherence was 3.4 (range 1.2-5.8). The vast majority of the travelers (83%) suffered from diarrhea. Most travelers (60%) had diarrhea for up to 3% of their journey time. Diarrhea was accompanied by fever among 18% and necessitated hospitalization in 3%. Forty-five percent indicated that they had lost traveling days due to diarrhea, for an average of 0.7% of the traveling time. We found no correlation between the percentage of traveling time with diarrhea and the following variables: adherence to the WHO recommendations, receipt of advice regarding prevention, duration of the trip, age, sex, and nationality of the travelers.

CONCLUSIONS

Dietary self-restraint of travelers as proposed by the WHO is both difficult to comply with and lacks a proven value for the long-term traveler to a developing country.

Pharmacotherapy, vaccines and malaria advice for HIV-infected travellers

Since the introduction of effective antiretroviral therapy (ART), HIV-infected individuals are travelling more frequently and international travel has become much safer. Specific concerns include the safety of ART during travel, drug adherence and interaction considerations, and effects of immunosuppression. This review describes potentially important infections, vaccine effectiveness, safety and special approaches for their use, and HIV-related issues regarding predeparture counselling. With advanced immunosuppression (CD4+ T-cell count < 200/microl or < 14%), the immunogenicity of several vaccines is reduced, complications could occur after live attenuated vaccines and certain infections acquired during travel may be more frequent or severe. Challenges include the best options for malaria chemoprophylaxis, standby treatment and medical follow-up of the increasing number of HIV-infected long-term travellers.

Traveller's diarrhoea

Traveller's diarrhoea affects over 50% of travellers to some destinations and can disrupt holidays and business trips. This review examines the main causes and epidemiology of the syndrome, which is associated with poor public health infrastructure and hygiene practices, particularly in warmer climates. Although travellers may be given common sense advice on avoidance of high-risk foods and other measures to prevent traveller's diarrhoea, adherence to such advice is sometimes difficult and the evidence for its effectiveness is contradictory. However, non-antimicrobial means for prevention of traveller's diarrhoea are favoured in most settings. A simple stepwise approach to the management of traveller's diarrhoea includes single doses or 3-day courses of antimicrobials, often self administered. The antibiotics of choice are currently fluoroquinolones or azithromycin, with an emerging role for rifaximin. In the long term, there will be greater benefit and effect on the health of local inhabitants and travellers from improving public health and hygiene standards at tourist destinations.

Update in traveler's diarrhea

TD has not proved as preventable as hoped, despite knowing that it is transmitted mainly through food. Travelers have little ability to select restaurants based on the kitchen hygiene. The rates of TD in travelers to developing countries have not changed in the past 50 years, either because the dietary precautions they are taught are not effective or they cannot be adhered to in the course of a pleasurable vacation. Nonantibiotic prophylaxis with bismuth subsalicylate has the potential to prevent 40% to 60% of TD episodes in short-term travelers, and is probably underused. Antibiotic prophylaxis can prevent up to 90% of infections, but is not routinely recommended. Empiric treatment of TD has been the best approach to dealing with this problem, but its usefulness is being undermined by growing antibiotic resistance in many parts of the world. Fluoroquinolones are still the most useful agents where Campylobacter is not a predominant pathogen. Rifaximin may prove to be a useful addition to the options for treatment and prophylaxis. If used for treatment, it may require a backup antibiotic in areas where Campylobacter and Shigella are prominent pathogens.

Interventions to prevent and control food-borne diseases associated with a reduction in traveler's diarrhea in tourists to Jamaica

BACKGROUND

In 1996 a study found that approximately one in four tourists to Jamaica were affected with traveler's diarrhea (TD) during their stay. That year the Ministry of Health initiated a program for the prevention and control of TD. The aim of this ongoing program was to reduce attack rates of TD from 25% to 12% over a 5-year period by improving the environmental health and food safety standards of hotels.

METHODS

Hotel-based surveillance procedures for TD were implemented in sentinel hotels in Negril and Montego Bay in 1996, Ocho Rios in 1997, and Kingston in 1999. A structured program provided training and technical assistance to nurses, food and beverage staff, and environmental sanitation personnel in the implementation of Hazard Analysis Critical Control Point principles for monitoring food safety standards. The impact of interventions on TD was assessed in a survey of tourists departing from the international airport in Montego Bay in 1997-1998 and from the international airport in Kingston in 1999-2000. The impact of the training and technical assistance program on food safety standards and practices was assessed in hotels in Ocho Rios as of 1998 and in Kingston from 1999.

RESULTS

At the end of May 2002, TD incidence rates were 72% lower than in 1996, when the Ministry of Health initiated its program for the prevention and control of TD. Both hotel surveillance data and airport surveillance data suggest that the vast majority of travelers to Kingston and southern regions are not afflicted with TD during their stay. The training and technical assistance program improved compliance to food safety standards over time.

CONCLUSION

Interventions to prevent and control TD in visitors to Jamaica are positively associated with a reduction in TD in the visitor population and improvements in food safety standards and practices in hotels.

Travellers' diarrhea in children

Diarrhea is the most common medical problem affecting all travellers to developing countries. Younger children are at especially high risk of acquiring travellers' diarrhea and of suffering more severe consequences. Up to 50% of travellers from developed to developing countries can expect to have at least one episode of acute diarrhea during a two-week stay. Episodes of travellers' diarrhea usually begin abruptly, either during travel or soon after returning home, and are generally self-limited.

Incidence and precipitating factors of morbidity among Israeli travelers abroad

BACKGROUND

During recent years international travel, including visits to the developing world, has become increasingly popular. Many of these travelers suffer from some sort of health problem during their trip or after their return. Travelers clinics that give pretravel immunization and counseling have emerged. This study analyzes the incidence and risk factors for health problems among Israelis traveling abroad.

METHODS

The study surveyed by telephone 200 people who visited the traveler's clinic at Soroka Medical Center in Beer-Sheva during the years 1998 to 1999. The travelers were questioned after returning from their journey about the type and duration of the trip, compliance with medical advice given in the travel clinic, and health problems during the trip.

RESULTS

The mean age was 26.4 +/- 9.4 years, 7% went on an organized tour, 23% traveled alone, and 77% traveled with a friend. The mean duration of the trip was 14.7 +/- 13.4 weeks. Of the travelers, 70% reported some health impairment. Problems reported most frequently were gastrointestinal tract diseases (43%), respiratory tract diseases (25%), and injuries (10%). Only 4% were admitted to a hospital during their trip. After their return, 19.5% consulted a physician. Comparing the group of travelers who were sick with the rest, a correlation between noncompliance with the keeping of food hygiene and illness was found (p =.008). Additional risk factors for illness were long duration (p <.001), solitary trip (p =.04), and young age (p <.001). Of the people who were advised to take antimalaria chemoprophylaxis, 55% reported regular use of these drugs. Compliance with treatment correlated with older age (p <.001), short duration of stay (p =.01), previous experience, and travel to Africa (p <.001).

CONCLUSIONS

Most of the travelers to developing countries are young, travel for long periods, and live in basic conditions during their stay abroad. For these reasons travelers are at increased risk for morbidity. High risk travelers should be identified and counseled in order to increase their compliance with the medical advice and immunizations. A screening program for returning travelers should be considered.

Drug prophylaxis for travelers' diarrhea

Travelers' diarrhea is the most common health impairment in persons visiting developing countries, affecting 20% to >50% of tourists. Although it is usually benign, travelers' diarrhea represents a considerable socioeconomic burden for both the traveler and the host country. The most common enteropathogens are enterotoxigenic and enteroaggregative Escherichia coli. Travelers' compliance with dietary precautionary measures is poor. Despite the excellent protection rates provided by antibiotics, routine administration of prophylaxis is currently not recommended because of potential adverse reactions. Of the various antibiotics that have been tested, quinolones are considered to be the first choice worldwide; however, quinolone-resistant pathogens are increasingly being isolated. Because it is frequently administered and provides only moderate protection, bismuth subsalicylate is not considered a recommendable option for prophylaxis in Europe, where it is rarely available anyhow. To date, no probiotic has been able to demonstrate clinically relevant protection worldwide. In conclusion, there is no satisfactory prophylactic option, and worldwide monitoring of antimicrobial susceptibility patterns and the search for novel antimicrobial agents, such as nonabsorbed antibiotics, and nonantibiotic medications should continue.

Health problems in a large cohort of Americans traveling to developing countries

BACKGROUND

Millions of Americans visit developing countries each year, however, little is known about their health during travel. This study describes health problems in a large cohort of American travelers during and after their trip.

METHODS

A 2-year survey of 784 travelers (95% follow-up) was conducted for persons traveling for < or = 90 days. At the pretravel visit, travelers were given a postcard to record adverse health events. Following travel, standardized telephone interviews were performed for any positive responses, or if the card was not returned. All travelers were contacted 2 months after return to determine late occurring illness and compliance with antimalarials.

RESULTS

Travelers had a mean age of 44 years, a median duration of 19 days, and visited 123 countries. An illness was reported by 64% (1.6 illnesses per traveler). Ill travelers were more often female, and traveled longer than those who were not ill; depending upon destination, each day of travel increased by 3 to 4% the chance of becoming ill. Diarrhea was most common, occurring in 46%; 34% met a strict definition for traveler's diarrhea. Respiratory illness occurred in 26%, skin disorders in 8%, acute mountain sickness in 6%, motion sickness in 5%, accidents and injuries in 5%, and isolated febrile episodes in 3%. Medical care was sought by 8% of all travelers and 12% of those reporting illness. On return, 26% of travelers were ill, 56% of whom became ill after return. Diarrhea, respiratory illness, skin disorders, and febrile syndromes were most common, and 46% of those who were ill sought medical care. Complete compliance with antimalarials was 80%. Noncompliant individuals usually discontinued medications on return. Side effects were reported by 4% of those taking chloroquine, 11% of those taking chloroquine plus proguanil, and 14% of those taking mefloquine, with half of these neuropsychiatric. The incidence of documented malaria was 3.8 cases per 1,000 travelers.

CONCLUSIONS

Many travelers experience adverse health events during and after travel to the developing world. Attention to the prevention and therapy of traveler's diarrhea, prophylaxis of malaria, management of respiratory illness, personal safety, and access to medical care during travel, and, recognition of clinical syndromes after return, will help to improve the traveler's health.

A multiyear prospective study of the risk factors for and incidence of diarrheal illness in a cohort of Peace Corps volunteers in Guatemala

BACKGROUND

Diarrheal illness is the most common medical disorder among travelers from developed to developing countries and is common among expatriate residents in developing countries.

OBJECTIVE

To assess the risk factors for and incidence of diarrheal illness among Americans living in a developing country.

DESIGN

Prospective longitudinal study.

SETTING

Rural Guatemala.

PATIENTS

Cohort of 36 Peace Corps volunteers.

MEASUREMENTS

Collection of daily dietary and symptom data for more than 2 years; identification by multivariate Poisson regression analyses of risk factors for clinically defined episodes of diarrheal illness.

RESULTS

The 36 Peace Corps volunteers in this study had 307 diarrheal episodes (median, 7 per person), which lasted a median of 4 days (range, 1 to 112) and a total of 10.1% of the 23 689 person-days in the study. The incidence density (episodes per person-year) was 4.7 for the study as a whole, 6.1 for the first 6-month period, 5.2 for the second 6-month period, and 3.6 thereafter. Statistically significant risk factors for diarrheal illness included drinking water whose source (for example, the tap) and, therefore, quality, was unknown to the person; eating food prepared by a Guatemalan friend or family; eating food at a small, working-class restaurant; eating fruit peeled by someone other than a Peace Corps volunteer; drinking an iced beverage; and eating ice cream, ice milk, or flavored ices. The relative risks comparing the presence of these exposures during the first 6-month period overseas with their absence during the second year of residence ranged from 1.90 to 2.67, and the summary attributable risk percentage (that is, the percentage of diarrheal episodes that could be ascribed to the exposures) was 75.4%. Exposures generally were riskier if they occurred during travel elsewhere in Guatemala rather than in the person's usual work area.

CONCLUSIONS

Diarrheal illness of mild-to-moderate severity continued to occur throughout Peace Corps service but decreased in incidence as length of stay increased. Various dietary behaviors increased the risk for diarrheal illness, which suggests that avoidance of potentially risky foods and beverages is beneficial.

A week in the life of a travel clinic

International travel has increased enormously in recent years. With the greater movement of people have come increased encounters with a wide variety of diseases: malaria, dengue, cholera, typhoid fever, Ebola virus, and many more. The need for greater scope, consistency, and knowledgeability in pretravel health care to meet these challenges has been met by the emergence of the discipline of travel medicine. Travelers are well advised to become informed of the risks they face and to take steps to minimize those risks. After reviewing a traveler's medical history and a detailed itinerary, a travel medicine practitioner can offer expert advice on behavioral modifications, immunizations, and chemoprophylaxis regimens which will increase the traveler's margin of safety. The issues most frequently addressed in a travel clinic include treatment of traveler's diarrhea, malaria chemoprophylaxis, and immunizations, for hepatitis A, typhoid fever, tetanus/diphtheria, influenza, pneumococcus, hepatitis B, polio, meningococcus, measles, mumps, rubella, varicella, and rabies. Pretravel consultation must consider the age and underlying health problems of the traveler, the nature of the trip (wilderness, jungle, rural, urban, resort, or cruise), the duration of travel, and the latest available information on the site in terms of disease outbreaks, terrorism, and natural calamities.

Impact of Travel-Related Health Impairments

Background: Few recent data exist on the impact of travel-related health problems. Methods: A cohort study was conducted with follow-up by questionnaire of 2567 persons who had consulted the Zurich University Travel Clinic for travel health advice prior to visiting a developing country or eastern Europe. Of those questioned, 2109 (82.2%) could be evaluated. Results: More than one-third (800; 37.9%) had a health impairment, mainly illness leading to medical consultations in 224 (10.6%) individuals. Incapacitation was reported by 303 (14.4%) travelers, accounting for 2% of the total time abroad. The most frequent reasons for incapacitation were diarrhea and the common cold, particularly when accompanied by fever. Some 57 (7.1%) travelers consulted a doctor while abroad, and more than twice as many did so after returning home. Conclusions: This survey illustrates that despite efforts of travel medicine, the attack rate of health impairments remains virtually unchanged compared to 20 years ago. It provides one of the first overviews of incapacitation in travelers. To reduce the duration of incapacitation, one may wish to consider a travel kit which allows the patient self therapy for frequent and uncomplicated ailments.