Travel Medicine Clinic Research Articles

Business travel-associated illness: a GeoSentinel analysis.

Analysis of a large cohort of business travelers will help clinicians focus on frequent and serious illnesses. We aimed to describe travel-related health problems in business travelers. GeoSentinel Surveillance Network consists of 64 travel and tropical medicine clinics in 29 countries; descriptive analysis was performed on ill business travelers, defined as persons traveling for work, evaluated after international travel 1 January 1997 through 31 December 2014. Among 12 203 business travelers seen 1997-2014 (14 045 eligible diagnoses), the majority (97%) were adults aged 20-64 years; most (74%) reported from Western Europe or North America; two-thirds were male. Most (86%) were outpatients. Fewer than half (45%) reported a pre-travel healthcare encounter. Frequent regions of exposure were sub-Saharan Africa (37%), Southeast Asia (15%) and South Central Asia (14%). The most frequent diagnoses were malaria (9%), acute unspecified diarrhea (8%), viral syndrome (6%), acute bacterial diarrhea (5%) and chronic diarrhea (4%). Species was reported for 973 (90%) of 1079 patients with malaria, predominantly Plasmodium falciparum acquired in sub-Saharan Africa. Of 584 (54%) with malaria chemoprophylaxis information, 92% took none or incomplete courses. Thirteen deaths were reported, over half of which were due to malaria; others succumbed to pneumonia, typhoid fever, rabies, melioidosis and pyogenic abscess. Diarrheal illness was a major cause of morbidity. Malaria contributed substantial morbidity and mortality, particularly among business travelers to sub-Saharan Africa. Underuse or non-use of chemoprophylaxis contributed to malaria cases. Deaths in business travelers could be reduced by improving adherence to malaria chemoprophylaxis and targeted vaccination for vaccine-preventable diseases. Pre-travel advice is indicated for business travelers and is currently under-utilized and needs improvement.

Zika beyond the Americas: Travelers as sentinels of Zika virus transmission. A GeoSentinel analysis, 2012 to 2016.

BackgroundZika virus (ZIKV) was first isolated in Africa; decades later, caused large outbreaks in the Pacific, and is considered endemic in Asia. We aim to describe ZIKV disease epidemiology outside the Americas, the importance of travelers as sentinels of disease transmission, and discrepancies in travel advisories from major international health organizations.Methods and findingsThis descriptive analysis using GeoSentinel Surveillance Network records involves sixty-four travel and tropical medicine clinics in 29 countries. Ill returned travelers with a confirmed or probable diagnosis of ZIKV disease acquired in Africa, Asia and the Pacific seen between 1 January 2012 and 31 December 2016 are included, and the frequencies of demographic, trip, and diagnostic characteristics described. ZIKV was acquired in Asia (18), the Pacific (10) and Africa (1). For five countries (Indonesia, Philippines, Thailand, Vietnam, Cameroon), GeoSentinel patients were sentinel markers of recent Zika activity. Additionally, the first confirmed ZIKV infection acquired in Kiribati was reported to GeoSentinel (2015), and a probable case was reported from Timor Leste (April 2016), representing the only case known to date. Review of Zika situation updates from major international health authorities for country risk classifications shows heterogeneity in ZIKV country travel advisories.ConclusionsTravelers are integral to the global spread of ZIKV, serving as sentinel markers of disease activity. Although GeoSentinel data are collected by specialized clinics and do not capture all imported cases, we show that surveillance of imported infections by returned travelers augments local surveillance system data regarding ZIKV epidemiology and can assist with risk categorization by international authorities. However, travel advisories are variable due to risk uncertainties.

Challenges to providing pre-travel care for travellers visiting friends and relatives: an audit of a specialist travel medicine clinic.

Travellers visiting friends and relatives (VFRs) often have complex pre-travel needs. We identified the characteristics, destinations, vaccinations and pre-travel advice provided to VFRs and compared these with non-VFR travellers. The significant differences we found suggest that future research should focus on improving the uptake of recommended interventions in VFR travellers.

Pretravel Health Preparation of International Travelers: Results From the Boston Area Travel Medicine Network

ObjectiveTo inform future interventions for advising travelers.Patients and MethodsWe prospectively collected data on travelers seen at the Boston Area Travel Medicine Network, a Boston area research collaboration of 5 travel medicine clinics. Data from 15,440 travelers were collected from March 1, 2008, through July 31, 2010. We compared traveler and trip characteristics and differences in demographic characteristics and travel plans across the 5 clinics, including an analysis of pretravel preparations for certain high-risk destinations.ResultsMore than half of the 15,440 travelers were female (8730 [56.5]), and 72.4% (10,528 of 14,545) were white; the median age was 34 years, and 29.4% of travelers (3077 of 10,483) were seen less than 2 weeks before their departure date. Substantial variation in racial background, purpose of travel, and destination risk existed across the 5 clinics. For example, the proportion of travelers visiting friends and relatives ranged from 7.6% (184 of 2436) to 39.0% (1029 of 2639) (18.7% [2876 of 15,360] overall), and the percentage of travelers to areas with malaria risk ranged from 23.7% (333 of 1403) to 52.0% (1306 of 2512). Although most clinics were likely to have prescribed certain vaccines for high-risk destinations (eg, yellow fever for Ghana travel), there was wide variability in influenza vaccine use for China travel.ConclusionSubstantial differences in clinic populations can occur within a single metropolitan area, highlighting why individual physicians and travel clinics need to understand the specific needs of the travelers they serve in addition to general travel medicine.

International Travelers’ Sociodemographic, Health, and Travel Characteristics: An Italian Study

BackgroundApproximately the 8% of travelers requires medical care, with the diagnosis of a vaccine-preventable disease. The aim of our study was to analyze the socio-demographic, health and travel characteristics of the Italian international travelers. MethodsWe conducted a cross sectional study from January 2015 to June 2016, at the Travel Medicine Clinic of Siena, asking the doctor to interview patients who attended the Clinic, recording socio-demographic and travel information, malaria prophylaxis, vaccinations. The data were organized in a database and processed by software Stata®. ResultsWe collected 419 questionnaires. Patients chose 71 countries for their travels; the favorite destinations were: India (6.31%), Thailand (6.31%), and Brazil (5.10%). The mean length of stay was 36.17 days. Italians, students, and freelancers tended to stay abroad for a longer time (mean: 36.4 days, 59.87 days and 64.16 days respectively). 33.17% of our sample used drugs for malaria chemoprophylaxis: 71.9% of them used Atovaquone/Proguanil (Malarone®), 26.6% used Mefloquine (Lariam®), 1.5% other drugs. The vaccinations that travelers mostly got in our study were to prevent hepatitis A (n = 264), the typhoid fever (n = 187), the Tetanus + Diphtheria + Pertussis (n = 165), the Yellow fever (n = 118) and the cholera (n = 78).Twenty-eight (6.68%) refused some recommended vaccinations. The vaccines mostly refused were for Typhoid fever (n = 20), hepatitis a (n = 9), and cholera (n = 9). ConclusionOur results demonstrated that Italian international travelers are at-risk because of their poor vaccinations adherence. This implies that pre-travel counseling is fundamental to increase the knowledge of the risks and the compliance of future travelers.

Pre-travel malaria chemoprophylaxis counselling in a public travel medicine clinic in S\xe3o Paulo, Brazil

BackgroundMalaria is one of the most prevalent parasitic diseases in the world and represents a threat to travellers visiting endemic areas. Chemoprophylaxis is the prevention measure used in travel medicine, avoiding clinical manifestations and protecting against the development of severe disease and death.MethodsRetrospective and descriptive analysis of malaria prevention data in travellers was recorded from a travel medicine clinic in São Paulo, Brazil, between January 2006 and December 2010. All the medical records of travellers, who had travelled to areas with risk of disease transmission, including Brazil, were analysed. Demographic characteristics of travellers, travel details and recommendations for preventing malaria were also seen.ResultsDuring the study period, 2836 pre-travel consultations were carried out on 2744 individuals (92 were consulted twice). The most common reasons for travelling were tourism and work. The most common destinations were Africa (24.5%), Europe (21.2%), Asia (16.6%) and locations within Brazil (14.9%). In general prophylaxis against malaria was recommended in 10.3% of all the consultations. African destinations vs Asian, Brazilian and other destinations and length of stay ≤30 days were independently associated with the higher odds of chemoprophylaxis recommendation after the logistic regression.ConclusionThe prophylaxis against malaria was recommended in 10.3% of the consultations. The authors believe that a coherent measure of malaria prevention in Brazil and for international travellers would be to recommend for all parts of the North Brazil, avoidance of mosquito bites and immediate consultation of a physician in case of fever during or after the journey is recommended.

Malaria in travellers returning or migrating to Canada: surveillance report from CanTravNet surveillance data, 2004-2014.

Malaria remains the most common specific cause of fever in returned travellers and can be life-threatening. We examined demographic and travel correlates of malaria among Canadian travellers and immigrants to identify groups for targeted pretravel intervention. Descriptive data on ill returned Canadian travellers and immigrants presenting to a CanTravNet site between 2004 and 2014 with a diagnosis of malaria were analyzed. Data were collected using the GeoSentinel data platform. This network comprises 63 specialized travel and tropical medicine clinics, including 7 Canadian sites (Vancouver, Calgary, Toronto, Ottawa, Winnipeg and Montréal), that contribute anonymous, delinked, clinician- and questionnaire-based travel surveillance data on all ill travellers examined to a centralized Structure Query Language database. During the study period, 20 345 travellers and immigrants were evaluated, and 93% had a travel-related diagnosis. Of these, 437 (2.1%) patients received 456 malaria diagnoses, the most common species being Plasmodium falciparum (n = 282, 61.8%). People travelling to visit friends and relatives were most well-represented (n = 169, 38.7%), followed by business travellers (n = 71, 16.2%). Sub-Saharan Africa was the most common source region, accounting for 341 (74.8%) malaria diagnoses, followed by South Central Asia (n = 55, 12%). Nigeria was the most well-represented source country, accounting for 41 cases (9.0%). India, a high-volume destination for Canadians, accounted for 40 cases (8.8%), 36 of which were caused by Plasmodium vivax. Of 456 malaria diagnoses, 26 (5.7%) were severe. Of 377 nonimmigrant travellers with malaria, 19.9% (n = 75) travelled for less than 2 weeks, and 7.2% (n = 27) travelled for less than 1 week. This analysis provides an epidemiologic framework for Canadian practitioners encountering prospective and returned travellers. It confirms the importance of preventive measures and surveillance associated with travel to sub-Saharan Africa and India, particularly by travellers visiting friends or relatives. Short-duration travel confers important malaria risk.

Infectious disease following travel to developed regions: a snapshot of presentations to an Australian travel medicine clinic.

Much of the travel medicine literature focuses on travel to 'developing' regions by travellers from 'developed' regions; however literature about travel to developed regions is scarce. This article examines presentations to a travel medicine clinic over a 17-year period with illnesses resulting from travel to developed regions. From a cohort of general presentations to the clinic of 1077 patients, 85 patients acquired infections due to travel to developed regions, with a total of 99 infectious diagnoses made. This serves to highlight the risk of infectious disease even among travel to only developed regions, and the importance of travel advice in these situations.

Practices and Attitudes to Prevention of Travel-related Infectious Diseases in United Arab Emirates

Introduction: Among the United Arab Emirates (UAE) population more and more people now consider travelling abroad. This is potentially problematic because travelling enhances exposure between hosts and pathogens and so people that travel are putting their health at risk. This concern makes it necessary that public education is provided to inform people of the risks of travelling abroad so that such risks can be minimized. Guidelines and advice on travelling abroad are available and easily accessible but several studies have shown that travellers do not always follow such advice. In this study, the aim was to look into the practices and attitudes of UAE residents in relation to prevention of travel-related infectious diseases. Methods: A cross-sectional study was conducted from February to April 2015, in different emirates of the UAE. A self-administered anonymous questionnaire was developed based on material acquired from similar studies. The methodology applied quota sampling whereby adults above the age of 18 who’d travelled abroad in the past year were chosen from the seven emirates. The number of participants selected from each emirate was proportionate to the population size of each state. Results: A total of 385 questionnaires were completed. A remarkable 70% of respondents indicated that they had not taken on any precautionary measures prior to travel. Of greater interest was that only 21% of participants had taken advice on health prior to travel, while the outstanding majority 79% reported that they had not taken advice. The most common source of advice had been taken from family and friends among those who had taken advice at 41%, while only 15.4% had acquired it from specialized travel medicine clinics. High risk perception, spending more preparation time and travelling for longer durations were important factors that encouraged pretrial health consultation and undertook preventive measures. Conclusion: This study revealed that UAE residents had not taken adequate measures to prevent travel related infectious diseases. Despite the limitations of this study, it still provides sufficient data to improve public health intervention directed at encouraging travellers to acquire pre travel health consultation.

Pre-travel advice seeking from GPs by travellers with chronic illness seen at a travel clinic.

Travellers are ageing and frequently report chronic illness. Pre-travel health advice is crucial, particularly in this subgroup, and general practitioners (GPs) are first in line for treatment adjustment before departure. Our aim is to evaluate pre-travel health advice seeking from GPs by travellers with chronic illness seen at a travel clinic. A cross-sectional observational survey using a questionnaire was conducted between August 2013 and July 2014 in travellers attending the travel medicine clinic of a tertiary university hospital in France. During the study, 2019 travellers were included. Mean age was 39.4 years (±18.8). Three hundred and ninety-one (19.4%) travellers reported a history of a chronic illness. Arterial hypertension and diabetes mellitus were the most frequently reported illnesses, affecting, respectively, 168 (8.3%) travellers and 102 (5.1%). Hajj pilgrims were more likely to report a history of chronic illness than other travellers. Only 810 (40.1%) travellers sought pre-travel advice from their GP. Six hundred and fifty-two (40.1%) healthy travellers and 158 (40.5%) travellers reporting chronic illness sought pre-travel advice from their GP (P = 0.96). Travellers with a history of chronic illness do not seek pre-travel health advice from their GP more frequently than healthy travellers. Travel health specialists are generally not the best practitioners to manage the care of underlying medical conditions presenting risks during travel. However, GPs offer continuity and disease management expertise to improve the specificity of pre-travel planning. Thus, ongoing collaboration between the traveller, GP and travel health specialist is likely to yield the best outcomes.

Travel itinerary uncertainty and the pre-travel consultation—a pilot study

Risk assessment relies on the accuracy of the information provided by the traveller. A questionnaire was administered to 83 consecutive travellers attending a travel medicine clinic. The majority of travellers was uncertain about destinations within countries, transportation or type of accommodation. Most travellers were uncertain if they would be visiting malaria regions. The degree of uncertainty about itinerary potentially impacts on the ability of the travel medicine specialist to perform an adequate risk assessment, select appropriate vaccinations and prescribe malaria prophylaxis. This study reveals high levels of traveller uncertainty about their itinerary which may potentially reduce the effectiveness of their pre-travel consultation.

Profile of Travelers With Preexisting Medical Conditions Attending a Specialist Travel Medicine Clinic in Ireland.

Patients with complex medical comorbidities travel for protracted periods to remote destinations, often with limited access to medical care. Few descriptions are available of their preexisting health burden. This study aimed to characterize preexisting medical conditions and medications of travelers seeking pre-travel health advice at a specialized travel medicine clinic. Records of travelers attending the Galway Tropical Medical Bureau clinic between 2008 and 2014 were examined and information relating to past medical history was entered into a database. Data were recorded only where the traveler had a documented medical history and/or was taking medications. Of the 4,817 records available, 56% had a documented medical history and 24% listed medications. The majority of travelers with preexisting conditions were female. The mean age of the cohort was 31.68 years. The mean period remaining before the planned trip was 40 days. Southeast Asia was the most popular single destination, and 17% of travelers with medical conditions were traveling alone. The most frequently reported conditions were allergies (20%), insect bite sensitivity (15%), asthma (11%), psychiatric conditions (4%), and hypertension (3%). Of the 30 diabetic travelers, 14 required insulin; 4.5% of travelers were taking immunosuppressant drugs, including corticosteroids. Half of the female travelers were taking the oral contraceptive pill while 11 travelers were pregnant at the time of their pre-travel consultation. This study provides an insight into the medical profile of travelers attending a travel health clinic. The diverse range of diseases reported highlights the importance of educating physicians and nurses about the specific travel health risks associated with particular conditions. Knowledge of the effects of travel on underlying medical conditions will inform the pre-travel health consultation.

Awareness of Rabies Risk in a Sample of Travelers Attending an Irish Travel Medicine Clinic

Introduction: Many countries endemic for the rabies virus are popular tourist destinations for travelers from developed countries. This study was designed to assess the level of awareness of rabies in a sample of travelers attending a travel medicine clinic and to assess whether the rabies-specific information provided verbally should be reinforced into a written form before the travelers complete their rabies pre-exposure prophylaxis. Methods: During a 4-month period travelers intending to travel to rabies-endemic countries completed a questionnaire, and received standardized information on rabies risk reduction. When they received booster doses of rabies vaccine, subjects were asked if they considered themselves at risk of rabies and they were also asked to list the steps they would take if bitten by an animal. Results: Thirty travelers participated in this study. A significant proportion of them underestimated their personal risk. This trend persisted at follow-up despite intervening education. Many travelers did not recognize trekking as a risk factor for rabies exposure. While most travelers were aware that dogs can transmit rabies, very few understood the risk posed by other warm-blooded animals. The majority of travelers expected to be safely treated in the event of developing rabies. Most travelers understood the importance of consulting a doctor following potential rabies exposure but a minority of travelers was aware of the need for immediate first-aid treatment. Conclusion: Travelers’ knowledge of the information provided during their medical consultation appears to decay rapidly. This study points to the importance of reinforcing this advice by providing a convenient reference guide which could be inserted into the traveler’s vaccination booklet. Keywords: Rabies, Risk, Travellers

Differential Diagnosis of Illness in Travelers Arriving From Sierra Leone, Liberia, or Guinea: A Cross-sectional Study From the GeoSentinel Surveillance Network

The largest-ever outbreak of Ebola virus disease (EVD), ongoing in West Africa since late 2013, has led to export of cases to Europe and North America. Clinicians encountering ill travelers arriving from countries with widespread Ebola virus transmission must be aware of alternate diagnoses associated with fever and other nonspecific symptoms. To define the spectrum of illness observed in persons returning from areas of West Africa where EVD transmission has been widespread. Descriptive, using GeoSentinel records. 57 travel or tropical medicine clinics in 25 countries. 805 ill returned travelers and new immigrants from Sierra Leone, Liberia, or Guinea seen between September 2009 and August 2014. Frequencies of demographic and travel-related characteristics and illnesses reported. The most common specific diagnosis among 770 nonimmigrant travelers was malaria (n = 310 [40.3%]), with Plasmodium falciparum or severe malaria in 267 (86%) and non-P. falciparum malaria in 43 (14%). Acute diarrhea was the second most common diagnosis among nonimmigrant travelers (n = 95 [12.3%]). Such common diagnoses as upper respiratory tract infection, urinary tract infection, and influenza-like illness occurred in only 26, 9, and 7 returning travelers, respectively. Few instances of typhoid fever (n = 8), acute HIV infection (n = 5), and dengue (n = 2) were encountered. Surveillance data collected by specialist clinics may not be representative of all ill returned travelers. Although EVD may currently drive clinical evaluation of ill travelers arriving from Sierra Leone, Liberia, and Guinea, clinicians must be aware of other more common, potentially fatal diseases. Malaria remains a common diagnosis among travelers seen at GeoSentinel sites. Prompt exclusion of malaria and other life-threatening conditions is critical to limiting morbidity and mortality. Centers for Disease Control and Prevention.

36: Characteristics and Risk Profiles of Paediatric International Travelers Visiting Friends and Relatives

International travelers are susceptible to a wide spectrum of travel related morbidities. Paediatric travelers, along with travelers visiting friends and relatives (VFR) are both recognized high-risk groups. Despite the rising number of paediatric VFR travelers, their characteristics and risk profiles are not well described. To describe the risk-determining demographic and travel characteristics of paediatric international travelers. A descriptive analysis was conducted on pre-travel consultations completed between January 2013 and May 2014 at a Tertiary Care Family Travel Medicine Clinic. Data on demographics and travel characteristics were extracted from 312 consultations that met the inclusion criteria. 50% of consultations were for children <18 years of age (n=156), of which 31% were for young children (<5 years of age). We compared putative factors between VFRs and non-VFRs among children only. VFR children were on average significantly younger than non-VFR children (mean±SD: 5.4±4.1 vs 10.6±5.2 years of age, P<0.01). They were more likely to visit destinations in Asia (48% vs 29%, P<0.05), travel for longer duration (median (IQR): 31 (21–59) vs 12 (10–21) days, P<0.01), and stay with locals, friends and/or relatives (81% vs 13%, P<0.01). They were less likely to visit destinations in the Caribbean (0% vs 20%, P<0.05), participate in organized tour groups (4% vs 66%, P<0.01) and stay in hotel accommodations (41% vs 74%, P<0.01). See selected results in Table 1. VFR children traveling internationally are on average younger, more likely to travel for longer duration, and stay with locals, friends and/or relatives. They are potentially more susceptible to travel-related morbidities due to their young age and high-risk travel characteristics. These findings can help develop targeted pre-travel care for VFR children traveling internationally.

English

Objective: Travel medicine services and training are well established in the British Isles, but the situation in Brazil has not been extensively described. Methodology: We conducted a review of literature related to travel to travel medicine services and training in Brazil. Results: Specialised travel medicine clinics catering for departing travellers and ill returnees exist in the large Brazilian urban centres of Rio de Janeiro and Sao Paulo. Travel medicine educational events have been hosted by various institutions. Conclusion: The approach to travel medicine in the British Isles, with its focus on education and training, continuing professional development, and standards of practice, may reasonably be adopted in Brazil.

Travel medicine resources for Canadian practitioners.

To provide travel medicine practitioners with a comprehensive (though not exhaustive) list of resources. Resources that appear to be most frequently used by health professionals currently practising this specialty have been included. Select members of TravelMed, an international e-mail discussion forum for travel medicine practitioners were informally canvassed and presented with a question regarding which travel medicine resources they find to be most useful. Their responses informed the development of this Statement. In addition, the opinions of experts in travel medicine were solicited to identify resources. The scope was international; however, particular attention was given to Canadian sources of information. Travel medicine resources are listed and organized into the following categories: Courses, conferences and local travel medicine groups; Books; Canadian recommendations; Handbooks; periodicals and reports; Journals; Internet medicine forums; Online subscription services; Outbreak reports and travel advisories; Sources of malaria recommendations; More useful websites; Travel medicine clinics in Canada and abroad; and Certification. There are many Canadian and international resources available to inform Canadian travel medicine practitioners.

Dermatoses among returned Canadian travellers and immigrants: surveillance report based on CanTravNet data, 2009-2012.

There is a lack of multicentre analyses of the spectrum of dermatologic illnesses acquired by Canadian travellers and immigrants. Our objective for this study was to provide a comprehensive, Canada-specific surveillance summary of travel-related dermatologic conditions in a cohort of returned Canadian travellers and immigrants. Data for Canadian travellers and immigrants with a primary dermatologic diagnosis presenting to CanTravNet sites between September 2009 and September 2012 were extracted and analyzed. Data were collected using the GeoSentinel data platform. This network comprises 56 specialized travel and tropical medicine clinics, including 6 Canadian sites (Vancouver, Calgary, Toronto, Ottawa and Montréal), that contribute anonymous, de-linked, clinician- and questionnaire-based travel surveillance data on all ill travellers examined to a centralized Structure Query Language database. Results were analyzed according to reason for most recent ravel: immigration (including refugee); tourism; business; missionary/volunteer/research and aid work; visiting friends and relatives; and other, which included students, military personnel and medical tourists. During the study period, 6639patients presented to CanTravNet sites across Canada and 1076 (16.2%) received a travel-related primary dermatologic diagnosis. Arthropod bites (n = 162, 21.5%), rash (n = 141, 18.7%), cutaneous larva migrans (n = 98, 13.0%), and skin and soft tissue infection (n = 92, 12.2%) were the most common dermatologic diagnoses or diagnostic bundles issued to returning Canadian tourists (n = 754, 70.1% of total sample). Patients travelling for the purpose of immigration (n = 63, 5.9%) were significantly more likely to require inpatient management of their dermatologic diagnoses (p<0.001) than those travelling for other purposes. This analysis of surveillance data details the spectrum of travel-related dermatological conditions among returning Canadian travellers in this cohort, and provides an epidemiologic framework for Canadian physicians encountering these patients.

Developing countries: health round-trip.

International travel can pose various risks to health, depending both on the health needs of the traveller and on the type of travel to be undertaken. Travellers intending to visit a destination in a developing country should consult a travel medicine clinic or medical practitioner before the journey. General precautions can greatly reduce the risk of exposure to infectious agents. Vaccination is a highly effective method of preventing certain infectious diseases. The aim of this study is to know the risks involved and the best way to prevent them.

Physiology in Medicine: A physiologic approach to prevention and treatment of acute high-altitude illnesses.

With the growing interest in adventure travel and the increasing ease and affordability of air, rail, and road-based transportation, increasing numbers of individuals are traveling to high altitude. The decline in barometric pressure and ambient oxygen tensions in this environment trigger a series of physiologic responses across organ systems and over a varying time frame that help the individual acclimatize to the low oxygen conditions but occasionally lead to maladaptive responses and one or several forms of acute altitude illness. The goal of this Physiology in Medicine article is to provide information that providers can use when counseling patients who present to primary care or travel medicine clinics seeking advice about how to prevent these problems. After discussing the primary physiologic responses to acute hypoxia from the organ to the molecular level in normal individuals, the review describes the main forms of acute altitude illness--acute mountain sickness, high-altitude cerebral edema, and high-altitude pulmonary edema--and the basic approaches to their prevention and treatment of these problems, with an emphasis throughout on the physiologic basis for the development of these illnesses and their management.