Essential Travel Medicine - Jane N. Zuckerman - ebook

Essential Travel Medicine ebook

Jane N. Zuckerman

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This 1st edition of Essential Travel Medicine provides an excellent concise introduction to the specialty of Travel Medicine. This core text will enable health care practitioners particularly those new to the clinical practice of Travel Medicine, to gain a fundamental understanding of the diverse and complex issues which can potentially affect the health of the many millions of people who undertake international travel. Jane N Zuckerman is joined by Gary W Brunette from CDC and Peter A Leggat from Australia as Editors. Leading international specialists in their fields have contributed authoritative chapters reflecting current knowledge to facilitate best clinical practice in the different aspects of travel medicine. The aim of Essential Travel Medicine is to provide a comprehensive guide to Travel Medicine as well as a fundamental knowledge base to support international undergraduate and postgraduate specialty training programmes in the discipline of Travel Medicine. The 1st edition of Essential Travel Medicine offers an indispensable resource of essential information for travel health practitioners, infectious disease specialists, occupational health specialists, public health specialists, family practitioners, pharmacists and other allied health professionals. This core text will appeal similarly to those training in Travel Medicine and to those who want a concise introduction to the subject or an ideal revision companion.

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CONTENTS

Cover

Title page

Copyright

List of contributors

Preface

Acknowledgments

SECTION I: Travel medicine

CHAPTER 1: Basic epidemiology of infectious diseases

References

CHAPTER 2: Basic epidemiology of non-infectious diseases

Introduction

Why do people travel?

Travel pattern?

Illness due to travel

Death while traveling

Morbidity while traveling

Risks

Providing advice to travelers

Conclusion

References

Chapter 3: Pre-travel health risk assessment

Introduction

Defining travel-related risk and the risk assessment

Pre-travel health consultation

Establishing the risks

Risk perception

Post-travel consultation

Conclusion

References

CHAPTER 4: Setting up a travel clinic

Introduction

Aims of the clinic

Conclusion

References

CHAPTER 5: Travel medicine resources

Introduction

Professional organizations

Professional journals

Travel medicine textbooks

Travel medicine training

Travel medicine practice guidelines

International organizations

Governmental organizations

Travel safety and security issues

Surveillance, disease outbreaks, and epidemiologic bulletins

Vaccine resources

Overseas medical assistance

Disease information

Electronic discussion forums/listservs

RSS feeds

Applications for smart phones and devices

SECTION II: Travel-related infectious diseases

CHAPTER 6: Travelers' diarrhea

The syndrome: clinical definitions, epidemiology, and microbiology

Chemoprophylaxis of travelers' diarrhea

Symptomatic treatment of travelers' diarrhea

Antibiotic treatment of travelers' diarrhea

References

CHAPTER 7: Vector-borne diseases

Epidemiology

Clinical manifestations

Diagnosis

Clinical management

Risk for international travelers

Prevention and control

References

CHAPTER 8: Yellow fever

Epidemiology

Clinical manifestation, diagnosis, and treatment

Yellow fever among travelers

Prevention

International certificate of vaccination or prophylaxis (ICVP)

Medical waivers (exemptions)

Requirements versus recommendations

YF risk classification for travelers

References

CHAPTER 9: Malaria

The disease and its lifecycle

Methods of prevention including prophylaxis and emergency stand-by treatment

References

CHAPTER 10: Respiratory disease

Causative agents

Respiratory pathogens associated with outbreaks

Risk in travelers

Clinical manifestations

Diagnosis

Treatment

Prevention

References

CHAPTER 11: Sexually transmitted infections

Introduction

STI exposure associated with travel and migration

Factors associated with increased exposure

Travel-associated STIs

Pre-travel interventions

Vaccines and chemoprophylaxis for STI agents

References

CHAPTER 12: Tropical skin infections

Bacterial infections

Fungal infections

Parasitic and ectoparasitic infections

Viral skin infections

References

CHAPTER 13: Rabies

Introduction

Epidemiology

Clinical manifestation, diagnosis, and treatment

Rabies vaccines

Pre-exposure prophylaxis

Post-exposure prophylaxis

Simplified scheme for economical rabies prophylaxis

References

CHAPTER 14: Vaccine-preventable diseases

Principles of vaccine immunology

Immunization and vaccination

Live vaccines

Inactivated vaccines

Administration of vaccines

Types of vaccines (Table 14.1)

References

SECTION III: Travelers with underlying medical problems and special needs

CHAPTER 15: Women's health and travel

Introduction

Pre-travel counseling

Pregnancy

Breastfeeding while traveling

Conclusion

References

CHAPTER 16: Traveling with children

Introduction

Pre-trip preparation for traveling children and adolescents

International adoption

References

CHAPTER 17: Travelers with underlying medical conditions

Introduction

Immunocompromised

Diabetes

Cardiovascular and respiratory disease

References

CHAPTER 18: The older traveler and traveling with disability

Introduction

General advice for the older or disabled traveler

The older traveler

The disabled traveler

Conclusion

References

CHAPTER 19: Visiting friends and relatives

Introduction

Who are VFRs?

Why are VFRs an important traveler subgroup?

Why are VFRs at increased risk of disease?

Which diseases are of particular importance among VFRs?

Engaging VFRs

Pre-travel advice for VFRs

References

CHAPTER 20: Migrants, refugees, and travel medicine

Introduction

The migration process and health

From medical screening to access to care

Health and diseases in migrants: a practitioner's perspective

Infectious diseases

Non-infectious diseases

Mental health and violence

Acquiring cultural competence

Caring for patients: a patient-based approach

References

CHAPTER 21: Study-abroad programs: student health and safety issues

Special risks faced by students who study and travel abroad

Special challenges for international travel

Risk management to support student health and safety abroad

Conclusion

References

CHAPTER 22: Humanitarian aid workers, disaster relief workers, and missionaries

Introduction

Historical overview

Current perspectives - the scope of need

The person

The place and prevalence gaps

The purpose

The processes

Post-deployment review

References

CHAPTER 23: Long-term travelers

Introduction

The pre-travel consultation

Malaria prevention in long-term travelers

Pre-travel medical assessment

Psychological considerations

Access to healthcare

Pregnancy and delivery

Post-travel support

References

SECTION IV: Environmental travel health risks

CHAPTER 24: Aviation and travel medicine

Physics of the flight environment

Physiology of flight

Clinical aspects of aviation medicine

Mental health issues in aviation

Conclusion

References

CHAPTER 25: Expedition and wilderness medicine

Traveling at extremes

Scuba and diving medicine

References

CHAPTER 26: Venomous poisonous animals and toxins

Introduction

Nature of human envenomation

Relevant statistics for human envenomations and poisonings

Preparedness for treating envenomation and poisoning

References

CHAPTER 27: Cruise ships and travel medicine

Introduction

Background

Staff and facilities on-board

Medical disembarkations and evacuation

Crew health

Passenger health

Pregnancy

Motion sickness

Infectious diseases

Risks ashore

Mental health

Dentistry

Dialysis

Sexual assault

Communications

Conclusion

References

CHAPTER 28: Mass gatherings and travel medicine

Overview

What is a “mass gathering”?

Important characteristics

Common health problems

Guidance for clinicians

Guidance for travelers

References

CHAPTER 29: Emergency care whilst abroad

Introduction

Accessing medical care abroad

Accessing dental care abroad

Aeromedical evacuation (AME)

Travel and evacuation insurance

Taking medications abroad

Conclusion

References

SECTION V: Post-travel medicine

CHAPTER 30: The returning traveler

Introduction

Is there a need for post-travel screening of asymptomatic travelers?

Specific exposures and screening

Possible screening tools

Conclusion

References

Index

End User License Agreement

List of Tables

Chapter 2

Table 2.1 Crude rate of traveler deaths and common causes.

Chapter 4

Table 4.1 Top ten tips.

Table 4.2 “6 × 6”: essential travel medicine resources in setting up a travel clinic.

Chapter 6

Table 6.1 Recommended agents for travelers' diarrhea chemoprophylaxis.

Table 6.2 Recommended agents for symptomatic treatment of travelers' diarrhea.

Table 6.3 Recommended antimicrobial agents for the treatment of travelers' diarrhea.

Chapter 9

Table 9.1 Human malaria – essentials.

Table 9.2 Antimalarials for treatment and prophylaxis.

Chapter 10

Table 10.1 Etiologic agents of upper and lower respiratory infections in travelers.

Table 10.2 Causes of pulmonary findings with peripheral blood eosinophilia.

Chapter 11

Table 11.1 Demographic and behavioral characteristics associated with higher frequency of casual sex during travel.

Table 11.2 Demographic and trip characteristics of ill travelers with an STI, by traveler category in GeoSentinel (

N

= 974 travelers).

Table 11.3 Top five STIs diagnosed among ill travelers, according to clinical setting and gender, in GeoSentinel (

N

= 1001 diagnoses, 974 travelers; travelers can have more than one STI diagnosis).

Chapter 13

Table 13.1 Intramuscular rabies vaccine regimens.

Table 13.2 Simplified robust scheme for economical intradermal rabies prophylaxis.

Table 13.3 Recommended criteria for post-exposure treatment, a modification of WHO recommendations.

Chapter 14

Table 14.1 Vaccines.

Chapter 16

Table 16.1 Malaria chemoprophylaxis for children.

Table 16.2 Vaccines for traveling children and adolescents.

Chapter 17

Table 17.1 Travel restrictions for individuals with underlying cardiovascular conditions.

Chapter 18

Table 18.1 Selected online resources for disabled travelers.

Chapter 20

Table 20.1 A few questions to elicit the patient's explanatory model.

Chapter 22

Table 22.1 Characteristics of humanitarian/missionary responses.

Chapter 23

Table 23.1 Some suggestions for carrying out a post-trip psychologic evaluation.

Chapter 24

Table 24.1 Guidelines for medical clearance.

Table 24.2 Fitness to fly assessment.

Chapter 25

Table 25.1 The most common prevention and treatment strategies for altitude illness.

Table 25.2 Risk factors for heat-related illness [12,22,23].

Table 25.3 Medications that increase the risk of heat-related illness.

Chapter 27

Table 27.1 Pre-travel advice for crew requesting a travel medicine consultation

a

.

Table 27.2 Pre-travel advice for passengers.

Chapter 28

Table 28.1 Characteristics of sample mass gatherings.

Chapter 29

Table 29.1 Contents of a basic travel medical kit.

Table 29.2 Basic contents of a medical equipment kit.

Chapter 30

Table 30.1 Case series of eosinophilia in returning travelers.

Table 30.2 Helminths in patients with eosinophilia (serology and stool microscopy).

List of Illustrations

Chapter 1

Figure 1.1 Presentations to GeoSentinel by diagnostic category and region (2007–2011), plus 2010 regional WTO traveler arrivals. Left vertical axis shows cumulative number of presentations to GeoSentinel sites by ill returned travelers during 2007–2011 according to syndromic presentation and region of illness acquisition. Right vertical axis (narrow gray bars) shows traveler arrivals in 2010 by region, according to WTO data. WTO, World Tourism Organization; Aust, Australia; NZ, New Zealand, N Africa, North Africa; ME, Middle East; SS Africa, sub-Saharan Africa; GU, genitourinary.

Chapter 3

Figure 3.1 Assessment of risk in travel health.

Chapter 8

Figure 8.1 Yellow fever vaccine recommendations.

Chapter 9

Figure 9.1 Plasmodial life cycle.

Chapter 11

Figure 11.1 Distribution of specific STI diagnoses among ill travelers, according to clinical setting in GeoSentinel (

N

= 1001 diagnoses, travelers can have more than one STI diagnosis).

Chapter 23

Figure 23.1 A tumbu fly diagnosed via telemedicine after emerging from a lesion in a patient previously treated for a skin abscess.

Chapter 24

Figure 24.1 Oxygen dissociation curve for blood.

Chapter 30

Figure 30.1 Proportion of morbidity per 100 patients.

Figure 30.2 Schistosomiasis map: countries or areas at risk, 2011.

Guide

Cover

Table of Contents

Preface

Begin Reading

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Essential Travel Medicine

 

EDITED BY

Jane N. Zuckerman, MD, FRCP, FRCPath, FFPH, FFPM, FFTM

Consultant in Travel MedicineHonorary Senior Lecturer, UCL Medical School, University College London, UK;Honorary Consultant, Royal Free London NHS Foundation Trust and Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK;Adjunct Professor, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Qld, Australia

Gary W. Brunette, MD, MS, FFTM

Chief, Travelers’ Health BranchDivision of Global Migration and QuarantineCenters for Disease Control and Prevention, Atlanta, GA, USA

Peter A. Leggat, AM, MD, PhD, DrPH, FAFPHM, FFPH, FFPM(Hon), FACTM(Hon), FFTM, FACAsM

Professor and Dean, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Qld, Australia;Visiting Professor, School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa;Conjoint Professor, School of Health Sciences, Faculty of Health, University of Newcastle, NSW, Australia;Adjunct Professor, Research School of Population Health, College of Medicine, Biology and Environment, Australian National University, Canberra, ACT, Australia

 

 

 

 

 

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List of contributors

Michael Bagshaw, MB, BCh, MRCS, FFOM, DAvMed, DFFP, FRAeSVisiting Professor of Aviation MedicineHonorary Civilian Consultant Adviser in Aviation Medicine to the ArmyKing's College LondonLondon, UK;Cranfield UniversityCranfield, UK

Sally S.J. Bell, MB BS, Master in Maritime MedicineClinical Quality ConsultantLondon, UK

Robert Bor, DPhil, CPsychol, CSci, FBPsS, UKCP, Reg FRAeSProfessor, Lead Consultant Clinical, Counselling and Health PsychologistRoyal Free London NHS Foundation Trust;Director, Dynamic Change ConsultantsLondon, UK

Gary W. Brunette, MD, MS, FFTMChief, Travelers' Health BranchDivision of Global Migration and QuarantineCenters for Disease Control and PreventionAtlanta, GA, USA

I. Dale Carroll, MD, FACOG, DTM&H, FFTM RCPS (Glasgow)Medical DirectorThe Pregnant TravelerSpring Lake, MI, USA

Ian C. Cheng, BE, BMed, DipOccEnvironHealth, DipAvMed, MPH, FAFOEM, FACAsMAdjunct Associate ProfessorCollege of Public Health, Medical and Veterinary SciencesJames Cook UniversityTownsville, Queensland, Australia;Staff Specialist - Occupational MedicineRoyal North Shore HospitalSydney, NSW, Australia

Anna Cristina C. Carvalho, MD, PhDResearcher in Public HealthLaboratory of Innovations in Therapies, Education and Bioproducts)Oswaldo Cruz Institute, FioCruzRio de Janeiro, Brazil

Eilif Dahl, MD, MHA, PhDProfessor Emeritus, University of BergenNorwegian Centre for Maritime MedicineHaukeland University Hospital5021 BergenNorway

Claire Davies, MRCP, MRCGO, DTM&H, MFTM RCPS (Glasgow)Medical Team Manager/Travel Health ClinicianInterHealth WorldwideLondon, UK

Charles D. Ericsson, MDProfessor of Medicine and Dr. and Mrs. Carl V. Vartian Professor of Infectious Diseases;Head, Clinical Infectious DiseasesUniversity of Texas Medical School at HoustonHouston, TX, USA

Philip R. Fischer, MD, DTM&HProfessor of PediatricsMayo ClinicRochester, MN, USA

Richard C. Franklin, BSc, MSocSc, PhDAssociate Professor, College of Public Health, Medical and Veterinary SciencesJames Cook UniversityTownsville, Queensland, Australia;Royal Life Saving Society, Australia

David O. Freedman, MDProfessor of Medicine and EpidemiologyDivision of Infectious DiseasesUniversity of Alabama at BirminghamBirmingham, AL, USA

Joanna Gaines, PhD, MPHDoctoral EpidemiologistTravelers' Health BranchDivision of Global Migration and QuarantineCenters for Disease Control and PreventionAtlanta, GA, USA

Mark D. Gershman, MDMedical EpidemiologistTravelers' Health BranchDivision of Global Migration and QuarantineCenters for Disease Control and PreventionAtlanta, GA, USA

Brian D. Gushulak, BSc (Hon), MDMedical ConsultantMigration Health Consultants, Inc.P.O. Box 463Qualicum Beach, BC, Canada

Sean T. Hudson, MBBS, MSc, FAWM, Dip Mtn MedGeneral Practitioner and Honorary ConsultantAccident and EmergencyMaryport Health CentreWest Cumberland HospitalMaryport, Cumbria, UK;Director and Founder, Expedition MedicineCumbria, UK

Tomas Jelinek, MDMedical DirectorBerlin Center for Travel and Tropical MedicineBerlin, Germany

Caroline J. Knox, MBBS MSc MRCGPGeneral Practitioner, Castlegate SurgeryCockermouth, Cumbria, UK;Founder, Expedition MedicineCumbria, UK

Tamar Lachish, MDSenior Doctor, Infectious Diseases Unit and the Internal Medicine WardShaare-Zedek Medical CenterJerusalem, Israel

Ted Lankester, MA, MB, Bchir, MRCGP, FFTM, RSPSGDirector of Health ServicesInterHealth WorldwideLondon, UK

Regina LaRocque, MD, MPHCo-Director, Global TravEpiNet (GTEN) ProgramMassachusetts General Hospital;Assistant Professor of Medicine, Harvard Medical SchoolBoston, MA, USA

Karin Leder, MBBS, FRACP, PhD, MPH, DTMHAssociate Professor, Head of Infectious Disease Epidemiology UnitDepartment of Epidemiology and Preventive MedicineSchool of Public Health and Preventive MedicineMonash UniversityMelbourne, VIC, Australia;Head of Travel Medicine and Immigrant HealthRoyal Melbourne Hospital at the Doherty Institute for Infection and ImmunityMelbourne, VIC, Australia;Victorian Infectious Diseases ServiceRoyal Melbourne HospitalParkville, VIC, Australia

Peter A. Leggat, AM. MD, PhD, DrPH, FAFPHM, FFPH, FFPM(Hon), FACTM(Hon), FFTM, FACAsMProfessor and Dean, College of Public Health, Medical and Veterinary SciencesJames Cook UniversityTownsville, Queensland, Australia;Visiting Professor, School of Public Health, Faculty of Health SciencesUniversity of the WitwatersrandJohannesburg, South Africa;Conjoint Professor, School of Health SciencesFaculty of HealthUniversity of NewcastleNewcastle, New South Wales, Australia;Adjunct Professor, Research School of Population HealthCollege of Medicine, Biology and EnvironmentAustralian National UniversityCanberra, ACT, Australia

Louis Loutan, MD, MPHProfessor, Division of International and Humanitarian MedicineDepartment of Community Medicine and Primary CareUniversity Hospital of GenevaGeneva, Switzerland

Douglas W. MacPherson, MD, MSc(CTM), FRCPCMigration Health Consultants, Inc.Qualicum Beach, BC, Canada;Associate Professor, Pathology and Molecular MedicineMcMaster UniversityHamilton, ON, Canada

Karen J. Marienau, MD, MPHMedical Consultant and AdvisorSt. Paul, MN, USA;Formerly Division of Global Migration and QuarantineUS Centers for Disease Control and PreventionAtlanta, GA, USA

Alberto Matteelli, MDHead of Community Infection UnitClinic of Infectious and Tropical DiseasesSpedali Civili HospitalUniversity of BresciaBrescia, Italy

Anne E. McCarthy, MD, MSc, FRCPC, DTM&H, FASTMHProfessor of Medicine, University of Ottawa;Director, Tropical Medicine and International Health ClinicUniversity of OttawaOttawa, Canada

Sarah L. McGuinness, MBBS, BMedSc, DTMHInfectious Diseases RegistrarVictorian Infectious Diseases ServiceRoyal Melbourne HospitalParkville, VIC, Australia

Karl Neumann, MD, FAAP, CTMClinical Associate Professor of PediatricsWeill Medical College of Cornell University, USA;Clinical Associate Attending PediatricianNew York Presbyterian Hospital–Cornell Medical CenterNew York, (emeritus) USA; Attending PediatricianLong Island Jewish Hospital, USA; DirectorFamily Travel and Immunization Clinic of Forest Hills, Queens, USA

Gilles Poumerol, MDMedical OfficerTravel Health, Information & CommunicationGlobal Capacities Alert & ResponseWorld Health OrganizationGeneva, Switzerland

Mark A. Read, PhDSenior Instructor, Expedition and Wilderness MedicineThuringowa Central. Queensland, Australia

Gary Rhodes, PhDDirector, Center for Global EducationGraduate School of Education and Information StudiesUniversity of California at Los AngelesLos Angeles, CA, USA

Sara Ritchie, MBChB, MRCGP, DFFP, DTM&H, MPH, Dip DermHonorary Clinical Fellow in Tropical and HIV DermatologyUniversity College London Hospitals NHS Foundation Trust London, UK

Edward T. Ryan, MD, FACP, FIDSA, FASTMHCo-Director, Global TravEpiNet (GTEN) ProgramDirector, Travelers' Advice and Immunization CenterMassachusetts General Hospital;Professor of Medicine, Harvard Medical School;Professor of Immunology and Infectious Diseases, Harvard School of Public HealthBoston, MA, USA

Patricia Schlagenhauf, PhDProfessor, University of Zürich Centre for Travel MedicineZürich, Switzerland

Eli Schwartz, MD, DTMHProfessor, Director of the Center for Geographic MedicineThe Chaim Sheba Medical CenterTel-Hashomer, Israel;Sackler School of MedicineTel-Aviv UniversityTel-Aviv, Israel.

Marc T.M. Shaw, DrPH, FRGS, FRNZCGP, FFTM (ACTM), FFTM RCPS (Glasgow), DipTravMedAdjunct Professor, College of Public Health, Medical and Veterinary SciencesJames Cook UniversityTownsville, Queensland, Australia;Medical Director, WORLDWISE Travellers Health CentresAuckland, New Zealand

David R. Shlim, MDMedical DirectorJackson Hole Travel and Tropical MedicineWilson Medical CenterWilson, WY, USA

Will Smith, MDMedical Director, Grand Teton National Park, Teton County Search and Rescue;Clinical Faculty, University of Washington School of Medicine;Emergency Medicine, St. John's Medical CenterJackson, WY, USA

Mark J. Sotir, PhD, MPHLead, Surveillance and Epidemiology TeamTravelers' Health BranchDivision of Global Migration and QuarantineCenters for Disease Control and PreventionAtlanta, GA, USA

J. Erin Staples, MD, PhDMedical EpidemiologistArbovirus Disease BranchDivision of Vector Borne DiseasesCenters for Disease Control and PreventionFort Collins, CO, USA

Kathryn N. Suh, MD, MSc, FRCPCAssociate Professor of MedicineUniversity of Ottawa;Division of infectious DiseasesUniversity of OttawaOttawa, Canada

Andrea P. Summer, MD, MSCRAssociate Professor of PediatricsMedical University of South CarolinaCharleston, SC, USA

Joseph Torresi, MBBS, BMedSci, FRACP, PhDNHMRC Practitioner FellowDepartment of Microbiology and ImmunologyThe Peter Doherty Institute for Infection and ImmunityUniversity of Melbourne;Associate Professor, Department of Infectious DiseasesAustin HospitalMelbourne, VIC, Australia

Alfons Van Gompel, MD, DTMSpecialist in Internal Medicine and Tropical MedicineAssociate Professor, Tropical MedicineChief Physician of the Medical Services and Travel Clinic of the Institute for Tropical MedicineAntwerp, Belgium

Francisco Vega-López, MD, MSc, PhD, FRCP, FFTM, RCPSGConsultant Dermatologist and Honorary ProfessorUniversity College London Hospitals NHS Foundation TrustLondon, UK

Abinash Virk, MDAssociate Professor, Internal MedicineMayo Medical SchoolDivision of Infectious DiseasesMayo ClinicRochester, MN, USA

Mary J. Warrell, MB BS, FRCP, FRCPathHonorary Research AssociateOxford Vaccine GroupUniversity of Oxford;Centre for Clinical Vaccinology and Tropical MedicineChurchill HospitalOxford, UK

Annelies Wilder-Smith, MD, PhDProfessor in Infectious DiseasesLee Kong Chian School of MedicineNanyang Technological UniversitySingapore

Claire S. Wong, RN, MSc, FFTM RCPS (Glasgow)Travel Health Specialist NurseWORLDWISE Travellers Health CentresAuckland, New Zealand

Jane N. Zuckerman, MD, FRCP, FRCPath, FFPH, FFPM, FFTMConsultant in Travel Medicine;Honorary Senior Lecturer, UCL Medical SchoolUniversity College London, London, UK;Honorary Consultant, Royal Free London NHS Foundation Trust and Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK;Adjunct Professor, College of Public Health, Medical and Veterinary SciencesJames Cook UniversityTownsville, Queensland, Australia

Preface

The discipline of travel medicine continues to develop with established roots and structures worldwide. The necessity for the clinical practice of travel medicine in the prevention of ill health has never been more understood than now, with ever-increasing numbers of people traveling and criss-crossing the world alongside the potential hazards that travelers themselves may be exposed to and also the potential inherent risk to public health and populations internationally as a consequence of travel. Protecting travelers and, concomitantly, communities and populations requires the skill and expertise of travel medicine practitioners whose knowledge base is underpinned by continued professional development. Knowledge and education go hand in hand, with specialist training being an essential element, so enabling best clinical practice in a constantly evolving specialty.

The purpose of this book is to support those studying for a qualification or higher degree in travel medicine, and it is hoped that it will be used alongside and complement travel medicine reference books. This book is designed not only to support postgraduate training in the discipline but also to encourage undergraduate training in travel medicine in the curriculum of multidisciplinary healthcare training programs. It has been written in a style to complement lectures, with easily accessible information on the core topics required to enable the day-to-day clinical practice of travel medicine. Authors from different continents were chosen specifically in order to represent a range of views reflecting clinical practice and training courses that are available in different countries through the world.

It is hoped that this book will become a useful aide for those furthering their knowledge in addition to being a practical guide that will enhance the clinical practice and profile of travel medicine as a specialty. For those new to the growing discipline of travel medicine, an aspiration is that this book will stimulate interest and enthusiasm for the discipline for the next generation of travel medicine practitioners.

Jane N. ZuckermanGary W. BrunettePeter A. Leggat

Acknowledgments

The Editors would like to thank Maria Khan and Oliver Walter of Wiley-Blackwell for their enthusiasm, patience, and commitment that enabled the publication of this new book in travel medicine. In addition, we would like to thank Jennifer Seward and Jasmine Chang, also of Wiley-Blackwell, for all their help in the preparation of this edition. We would also like to thank all the authors for contributing to this book and to supporting the future development of the discipline of travel medicine. In particular, we would like to thank our families for their unfailing support and understanding, specifically Eugene, Tunde, and Pan, without whom this new textbook would not have been realized.

SECTION ITravel medicine

CHAPTER 1Basic epidemiology of infectious diseases

Mark J. Sotir1 & David O. Freedman2

1Centers for Disease Control and Prevention, Atlanta, GA, USA

2University of Alabama at Birmingham, Birmingham, AL, USA

Infectious conditions comprise a substantial portion of texts and guidelines related to travel medicine [1,2]. To prescribe optimal pre-travel advice, preventive measures, and education to travelers, travel health providers must be familiar with basic epidemiologic concepts, and also the epidemiology and geographic distribution of relevant infections. As past experience may predict future risk, a traveler-specific risk assessment allows possible measures, advice, and behavior modification to be appropriately prioritized for each traveler.

During the past two decades, the most important and relevant data on travel-related disease have come from surveillance of travelers themselves. Although available Ministry of Health data based on people native to an endemic locale may reflect national or state-level trends and identify the most important diseases to monitor within a country, the risk behaviors, eating habits, accommodations, knowledge of preventive measures, and precise itineraries of travelers can differ greatly from those of local populations. The GeoSentinel surveillance system, a collaborative effort between the International Society of Travel Medicine and the US Centers for Disease Control and Prevention, maintains the largest such surveillance database, with more than 200,000 records from patients with a confirmed or probable travel-related diagnosis. GeoSentinel is a global provider-based network of travel and tropical medicine clinics, which, as of August 2013, has 57 participating clinics on six continents. Details of the standard data collection instrument, diagnostic categories, and patient classification methods used in GeoSentinel have recently been published [3]. The network also facilitates rapid communication, obtains data, and reports on unusual or newly emerging health events in travelers [3].

The most recent surveillance results on travelers published from the GeoSentinel network [4] indicate that Asia (32.6%) and sub-Saharan Africa (26.7%) were the most common regions where illnesses were acquired (Figure 1.1). Three-quarters of travel-related illness was due to gastrointestinal (34.0%), febrile (23.3%), and dermatologic (19.5%) diseases. Malaria, dengue, enteric fever, spotted-fever group rickettsioses, chikungunya, and non-specific viral syndromes remained the most important of the acute systemic febrile illnesses. Falciparum malaria was mainly acquired in West Africa, and enteric fever was largely contracted on the Indian subcontinent; leptospirosis, scrub typhus, and murine typhus were principally acquired in South-East Asia. More than two-thirds of dengue infections were acquired in Asia, mostly Thailand, Indonesia, and India; seasonality of dengue varies according to destination. Common skin and soft tissue infections, mosquito bites (often infected), and allergic dermatitis remain the most common dermatologic conditions affecting travelers; of the more exotic infections, hookworm-related cutaneous larva migrans, leishmaniasis, myiasis, and tungiasis are the most important. The relative frequency of many diseases varies with both travel destination and reason for travel, with travelers visiting friends and relatives (VFRs) in their country of origin having both a disproportionately high burden of serious febrile illness (malaria) and very low rates of seeking advice before travel (18.3%). Although the most travel-related illness seen in GeoSentinel clinics comes from Asia, the proportion of travelers who become ill enough to seek specialized care appears to be much higher in travelers returning from Africa or Latin America. Only 40.5% of all ill travelers reported pre-travel medical visits.

Figure 1.1 Presentations to GeoSentinel by diagnostic category and region (2007–2011), plus 2010 regional WTO traveler arrivals. Left vertical axis shows cumulative number of presentations to GeoSentinel sites by ill returned travelers during 2007–2011 according to syndromic presentation and region of illness acquisition. Right vertical axis (narrow gray bars) shows traveler arrivals in 2010 by region, according to WTO data. WTO, World Tourism Organization; Aust, Australia; NZ, New Zealand, N Africa, North Africa; ME, Middle East; SS Africa, sub-Saharan Africa; GU, genitourinary.

Source: Adapted from Leder et al. 2013 [4].

Regional surveillance networks such as TropNet, a consortium of European centers, have contributed additional information on large numbers of travelers with dengue, schistosomiasis, leishmaniasis, and in particular malaria [5]. Sentinel event detection has led to notifications of outbreaks of travel-related African trypanosomiasis [6], leptospirosis, and malaria that have been indicative of possible changes in destination-specific risk.

Although GeoSentinel and similar traveler surveillance networks offer many advantages over disease-specific studies or data collated at single centers, they have several limitations. The reported cases represent a sentinel convenience sample of ill returned travelers visiting specialist clinics and do not reflect the experience of healthy travelers or those with mild or self-limited illness who visit primary care practices or other healthcare sites. In addition, referral patterns, patient populations, and travel demographic characteristics are not consistent between sites. Although collecting data exclusively from ill patients does not permit absolute or relative risks to be determined, the available data do show the relative frequency and range of illnesses seen in wide samples of travelers.

Estimates of true incidence and true risk in travelers (often expressed as number of events per 100,000 travelers) have been elusive for a number of reasons. Although a number of approaches to measure risk have been discussed in detail [7], such estimates have been limited in terms of obtaining both an accurate numerator (number of cases of disease) and denominator (number of travelers overall or to a specific destination who are susceptible to infection and illness). Many travelers to a specific location who become infected or ill will have returned to their home country by the time they develop signs and symptoms, so will not be captured by surveillance in the country of exposure, even if reporting is good. Similarly, diseases with short incubation periods may have resolved by the return home and not be captured in the country of origin. A denominator for all travelers to a specific location that could be used to calculate incidence is also generally problematic, and those available are typically estimates provided only at the country or region level and not at the actual destination level [8].

Many of the cited data on incidence of infection in travelers, some of which were published more than three decades ago, are based on extrapolations of small single-site studies or limited data collected from small samples of travelers. Authoritative texts such as the 2014 US CDC Yellow Book [1] often contain tables of global risk estimates that may range from 20–40% of all travelers for travelers' diarrhea to 0.0001% for Japanese encephalitis for all travelers to Asia. Although such numbers are useful as a guide to relative disease risks in large populations, the travel advisor should always seek out the most destination-specific information possible. Unfortunately, for many diseases, such information is only available to the national or, at most, the first geographic administrative level and might apply only to native populations and not to travelers.

A number of factors are important in analyzing epidemiologic data on travel-related diseases or in interpreting published reports. First, the characteristics specific to the disease itself, such as mode of transmission (vector-borne, food-borne, water-borne, environmental exposure), incubation period, signs and symptoms, duration of illness, diagnostic testing, and importance of comorbidities in acquiring and presenting with illness, and clinical outcomes must be considered. Second, the presence, frequency, seasonality, and geographic distribution of the disease need to be assessed, and these might change over time due to outbreaks, emergence or re-emergence in new areas or populations, successful public health interventions, and other factors. Third, as discussed above, travelers represent a unique subset of individuals, hence their exposure might differ compared with that of residents of a destination country.

As a result, along with demographic characteristics, additional travel-specific variables that must be considered would be trip length, destinations (both current and previous), specific travel itineraries (if known), purpose of travel, and type of traveler; preparation before and behaviors during travel also factor into the epidemiology of travel illnesses. Some but not all of these variables are systematically collected by surveillance systems that either focus on travelers, such as GeoSentinel, or collect data on illnesses that affect travelers. In addition, travelers are a heterogeneous group, and because analyses are always composed of samples rather than entire populations, the sample profile must be carefully examined and disclosed. For example, VFRs have consistently represented higher proportions of serious febrile illness, particularly malaria, among travelers [9,10].

Data on the health characteristics and pre-travel healthcare of travelers are important to provide insight into the itinerary, purpose of travel, or existing medical conditions in order to prioritize the most relevant interventions and education. A US-based provider network, Global TravEpiNet (GTEN), systematically collects data from travelers presenting to a consortium of 26 travel and tropical medicine clinics. Of 13,235 travelers seen from 2009 to 2010 in GTEN clinics, India, South Africa, and China were the most common intended destinations for these travelers, with more than one-third of trips occurring in June, July, and August [11]. Travelers seen in sampled GTEN clinics ranged in age from 1 month to 94 years, with a median of 35 years. The median duration of travel was 14 days, although 22% of travelers pursued trips of >28 days, and 3% of travelers pursued trips of >6 months. About 75% were traveling to malaria-endemic countries; of the 72% who were prescribed an antimalarial, 70% of the prescriptions were for atovaquone/proguanil. Of the 87% of travelers who were prescribed an antibiotic for presumptive self-treatment of travelers' diarrhea, a fluoroquinolone or azithromycin was prescribed in almost equal proportions. Vaccines against hepatitis A and typhoid were the most frequently administered. About 38% of travelers were visiting yellow fever-endemic countries, for which they may need a vaccine requiring a higher level of practitioner knowledge. Immunocompromising conditions, such as HIV infection and AIDS, organ transplant, or receipt of immunocompromising medications, were present in 3% of travelers. Although this is a relatively large multicenter sample, GTEN is limited to a subset of specialized travel and tropical medicine clinics in the United States and does not capture travelers who seek pre-travel care from primary care and other providers, and data have only been collected since 2009.

As travel medicine continues to grow with regard to both number of practitioners and subject matter, infectious diseases will remain an important and perhaps an even greater component of the discipline. Likewise, the epidemiology of infectious diseases in travelers will remain important, with surveillance and reporting potentially being enhanced and refined, resulting in more complete and informative data being available to both clinical and public health practitioners and allowing more informed decisions to be made with regard to protecting the health of the traveler.

References

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3 Harvey K, Esposito DH, Han P, et al. Surveillance for travel-related disease – GeoSentinel surveillance system, United States, 1997–2011.

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7 Leder K, Wilson M, Freedman DO, Torresi J. A comparative analysis of methodological approaches used for estimating risk in travel medicine.

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8 Behrens RH, Carroll B. The challenges of disease risk ascertainment using accessible data sources for numbers of travelers.

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CHAPTER 2Basic epidemiology of non-infectious diseases

Richard C. Franklin & Peter A. Leggat

James Cook University, Townsville, Queensland, Australia

Introduction

Travel can be an exciting mix of new experiences, friends, sights, food, and sensations. It can awaken a person's desire for adventure, but unfortunately it can also be fatal, and although most travel medicine focuses on the exotic, the infectious, and the unusual [1,2], it can be everyday activities, such as driving or living with a disease, that are the cause of tragedy. In this chapter, we explore the basic epidemiology of non-infectious disease while traveling, including illnesses due to travel, deaths, and morbidity while traveling, risk and risk factors, common causes of accidents and prevention strategies, the potential risks befalling children and older travelers, and dental problems encountered while traveling.

Establishing a picture of the modern travelers and their destinations is important for aiding our understanding of what types of non-infectious disease conditions may occur and how interventions might take place. This is part of the travel health risk assessment. Although travel medicine focuses on those traveling outside their country, usually abroad, there is a wider role for the travel medicine specialist in providing advice to all types of travelers, including those undertaking recreational activities close to home. Although an underexplored area, there are more people who travel within their country than those who travel to destinations abroad, yet few of these travelers seek advice about keeping themselves healthy and safe.

In this chapter, a broad definition of travel medicine has been used: travel medicine includes all those who travel (no matter what the distance) and who are exposed to a risk that is outside their normal day-to-day routine or where travel is a common part of their work environment that exposes them to risk where a travel medicine specialist would be an appropriate person from whom to seek advice. This would include the older traveler who is traveling with a caravan around their country and not used to traveling long distances, towing a caravan, or visiting sites that have different hazards from those at home such as caves with bats or waterways. It would also include the person who travels for work and is exposed to risky environments, such as divers or truck drivers traveling into areas where there are tropical diseases and hazards, sometimes lurking just below the water's surface.

Why do people travel?

The number of people traveling continues to grow, with over 1 billion international tourist arrivals in 2012 [3]; however, each person travels for a different reason, and this places each traveler at a different risk of injury or, for example, a cardiovascular event. Broadly, there are five groups of travel scenarios:

pleasure – leisure, recreation, and holidays;

visiting friends and relatives (VFR);

work related;

religion;

medical (including dental).

Even within each of these categories there are different groups of travelers; for example, within the work-related group there are those traveling to conferences, those who will be visiting hostile zones, and those working in the aftermath of a disaster or humanitarian crisis, each bringing its own risks. For the more dangerous work-related travel, the people traveling normally have full occupational medical examinations before traveling. Medical tourism continues to grow as the cost of medical care in developed countries increases, and this has its own risk [4]. There is also a subset of travelers who are seeking death (suicide) [5] as opposed to dark travel where the traveler seeks out sites of morbid fascination [6].

There is also a group who cross over between medical tourism and VFR. This group may travel with a chronic condition, such as cancer, and knowing they are unwell and may not have long to live, seek out relatives, friends, or just their country of birth to spend some of their last remaining time [7].

Travel pattern?

Travel patterns in the 20th and 21st centuries have seen dramatic changes in the way people move around the world and the volume of people traveling. In 2012, over half (52%) of all international travel was by air, 40% was by road, 6% by water and 2% by rail [3]. Although the majority of people travel by air, a recent study of people who died while traveling to the United States found that the majority (62%) of deaths were of people undertaking sea travel (predominately cruise ship passengers) (85%) and air travel (38%), with just one death associated with land travel [8]. These deaths were predominately (70%) from cardiovascular causes, followed by infectious disease (12%) and cancer (6%) [8]. Of the 26 deaths from infectious diseases, 19 also had an underlying chronic disease [8].

Illness due to travel

There are a range of illnesses caused by travel itself, with impact from minor illness to death. Conditions include motion sickness, jet lag, deep venous thrombosis (DVT), altitude sickness, sunburn, dehydration, and alcohol toxicity. See Chapters 3 and 24.

Motion sickness

Anyone can develop motion sickness if enough stimuli are provided [9]. Motion sickness is caused by the brain receiving conflicting sensory information. Risk factors that increase susceptibility include age, gender, people who get migraine headaches and some medications [9]. Approximately two-thirds of people who suffer from migraines are also sensitive to motion [10].

Jet lag

Jet lag is caused when a person's circadian rhythm is out of synchronization with external time cues [11], caused by traveling across three or more time zones [12]. It is estimated that it takes 1 day for each time zone change for the circadian system to realign; however, there is some variability depending on direction; westward is faster [11]. Common complaints include poor sleep, reduced performance, fatigue during the day, and gastrointestinal disturbances [12]. It is also more common in older people. Long-term consequences can include gastrointestinal problems, increased risk of cancer, infertility, and heart disease [11].

Venous thromboembolism

In a meta-analysis, venous thromboembolism (VTE) has been found to be twice as common among travelers than non-travelers. Traveling for longer periods was also found to increase the risk, with an 18–22% increase for every 2-hour increase in travel duration, and travelers were three time more likely to develop DVT or pulmonary embolism [13]. Other factors that have been identified as increasing the risk include age over 40 years, women using oral contraceptive drugs or hormone replacement therapy, obesity, varicose veins on the lower limbs, and genetic thrombophilia [14]. The incidence ranges from 0.2 to 4.8 per 1 million hours of flying [14].

Altitude illness

Altitude illness (sickness) is an issue of significance as more people take up the challenge of reaching new heights. It can occur when people travel above 2500 m and is divided into three syndromes, the most common being acute mountain sickness (AMS) [15]. In a study of trekkers on Mount Kilimanjaro [16], 3% were AMS positive at 2743 m and 47% at 4730 m. There was no difference between those who took a rest day at 3700 m; however, those who were preacclimatized had a significant reduction in AMS. This is consistent with advice that having exposure prior to moving to higher altitude is valuable; also, it is recommended to avoid alcohol, to ascend slowly at a rate of around 500 m each day after 2700 m, and to plan an extra day of acclimatization for every 1000 m [15]. See also Chapter 25.

Death while traveling

There is no definitive source on how many people die each year while traveling, nor do we know what the risk is of suffering death, illness, or injury while traveling. Estimates of risk vary depending on the country visited and the country of origin (Table 2.1). Some papers only explore particular types of death, such as injury-related death [17]; it does appear, however, that as more people are traveling so are more travelers dying [18,19].

Table 2.1 Crude rate of traveler deaths and common causes.

Ref.

Population

Time frame

No. of tourist deaths

No. of tourists

Crude rate per 100,000 visitors

Common causes of death

Leggat and Wilks 2009 [7]

Visitors to Australia

2000–2003

1063

34,396,700 (ABS)

0.77

Ischemic heart disease – 26% Malignant neoplasms – 16% Transport injury – 14% Drowning – 5% Suicide – 3%

Tonellato et al. 2009 [17]

Injury deaths of US travelers

2004–2006

2361

114,627,758

0.69

Vehicle accidents – 33% Violent deaths – 34% Drowning – 11% Air accidents – 3% Drug-related – 3% Disasters – 2%

Lunetta 2010 [18]

Finnish residents traveling abroad

1969–2007

6894

2005–2007 = 3,163,000

0.75

Natural causes – 67% Injuries – 27%

Redman et al. 2011 [20]

Scottish travelers

2000–2004

572

Trauma – 20% Non-infectious diseases – 75% Infectious diseases – 2%

Lawson et al. 2012 [8]

International travelers arriving in the USA

1 July 2005 to 30 June 2008

213

137,897,860 (

http://tinet.ita.doc.gov/

)

0.05

Cardiovascular – 70% Infectious diseases – 12% Cancer – 6% Unintentional injury – 4% Intentional injury – 1%

Pawun et al. 2012 [21]

Visitor to Chiang Mai, Thailand

2010 to 2012

102

Cardiac diseases – 35% Malignant neoplasms – 20% Infectious diseases – 12% Accidents – 4% Suicide – 4% Drug overdoses – 2% Drowning – 1%

MacPherson et al. 2007 [22]

Canadians traveling overseas

1996 to 2004

2410

166,680,000 (

http://www.statcan.gc.ca

)

0.95–2.79

Natural – 74% Accidental – 18% Suicide – 4% Homicide 4%

Morbidity while traveling

Our understanding of morbidity amongst travelers is predominately based on data collected in the 1980s [23] and is commonly acquired from insurance data and returning travelers. Unfortunately, common information about what happens to travelers overseas derived from insurance data often excludes pre-existing medical and dental conditions, as this is not covered under their insurance and the information does not include those not insured. We know from Australian data that a significant proportion of travelers require emergency assistance overseas, including for medical and dental problems, requiring medical or hospital treatment or, in a small number of cases, aero-medical evaluation [24]. Common conditions requiring assistance included musculoskeletal disorders (28%), gastrointestinal disorders (15%), dental conditions (14%), and respiratory problems (12%), demonstrating the significant and immediate impact of non-infectious conditions on travelers [24].

Common claims for non-infectious conditions identified in insurance data include musculoskeletal (16%), dental (7%), and cardiovascular (6%) [25]. A recent study exploring common conditions presenting to GeoSentinel clinics from returning travelers included some information on non-infectious conditions (although we note that infectious diseases make up a significant proportion of what is seen within these clinics) [23]. Common non-infectious conditions seen included underlying chronic disease (19/1000 patients), injury (14/1000 patients), neurologic disorders (15/1000 patients), psychologic disorders (12/1000 patients), and cardiovascular disease (8/1000 patients) and make up a very small number of the cases seen post-travel in GeoSentinel clinics [23]. See also Chapter 24.

Risks

Depending on the location where one is traveling, one is more likely to die from non-infectious than infectious causes. For example, in Australia between 2001 and 2003, the most common cause of death was from ischemic heart disease, followed by malignant neoplasms, and nearly one-quarter (23%) of the deaths were from accidents predominately related to transport (14% of all deaths) and drowning (5% of all deaths) [7], and US travelers traveling to Mexico were more likely to die from injuries (51%) than any other cause, followed by circulatory diseases (37%), with motor vehicle accidents and drowning being the most common types of injury event [26]. The type of activities in which a person participates also increases his or her risk of being injured or dying; for example, taking part in aquatic activities increases the risk of drowning, and road travel and the type of vehicle used increase the likelihood of being involved in a road traffic incident.

Exposure

Although it is difficult to determine if exposure to travel-related disease differs by gender, the reason why male and female travelers present to travel health advisers does vary, with females more likely to present with diarrhea, irritable bowel syndrome, upper respiratory tract infection, urinary tract infection, psychological stressors, oral and dental conditions, or adverse reactions to medication, whereas males are more likely to have febrile illnesses; vector-borne diseases such as malaria, leishmaniasis, or rickettsioses; sexually transmitted infections; viral hepatitis; or non-infectious problems, including cardiovascular disease, acute mountain sickness, and frostbite [27].

Exposure to travel-related disease is not static and changes depending on the activity that the person is undertaking, the location they are visiting, the time of year, how long they are staying in a particular area, and where they are staying. Much is known about risk and transmission of infectious diseases among travelers, including sexually transmitted infections, although again subpopulations such as adolescents are at greater risk [28]. Overseas travel involving British university students found that they were more likely to drink alcohol, use cannabis, and have casual sex during their holiday [28].

Risk taking

The difference between risk taking and perceived risk in travel is not well understood and is influenced by travelers' existing knowledge, beliefs, socio-cultural background, previous experiences, familiarity, and ability to identify and control risk [29]. It is interesting that perception of risk varies little between pre- and post-travel except for accidents, which increase post-travel; however, risks due to exposure to mosquitoes were perceived to be the highest risk [30]. Some risk taking is expected and is part of the reason why people travel [31]. Risk taking is also influenced by many factors, such as time of year, the activities being undertaken, length of stay, age, gender, and where people stay. For example visiting areas where there is snow in the winter would not only imply the presence of low temperatures and thus possible hypothermia, but also skiing-related injuries and the need for advice about using a helmet [32]. However, during summer trekking may be involved and participants should be aware of body-stressing issues, dehydration, and sunburn. It is also interesting that approximately half of travelers in a recent Australian study have participated in one activity with an injury risk in their last overseas trip, and males and those aged 18–24 years were significantly more likely to participate in at least one activity with an injury risk; common activities included motorcycles and/or off road vehicles (24%), water sports other than swimming (23%), and contact sports (8%) [33]. See also Chapters 3 and 5.

High-risk travelers

There are those travelers who are at a higher risk of being ill or sustaining an injury when traveling, and also those with underlying medial and physical conditions that may worsen while traveling [34]. People who may be at higher risk of being injured include those intending to undertake thrill-seeking or risky activities, sports, going to places where there are known risks such as the “full moon festival” [35], and those who have underlying health conditions that may place them at greater risk of injury or death, such as people with cardiovascular or respiratory conditions who undertake scuba diving or snorkeling [36]. It should also be noted that some high-risk activities are excluded under the terms and conditions of travel insurance policies, hence for those intending to undertake these activities, careful consideration of the policy is recommended.

Providing advice to travelers

The challenge for all travel medicine consultants is to have the difficult conversation around what people may do while traveling – most of the time people are interested in having their vaccinations to protect them against infectious disease and do not want to discuss the things that may kill them! There are a range of risky activities that people undertake when they travel: by far the most dangerous is being on the road, followed by being in, on, or around water, which includes scuba diving, boating, and marine creatures. There are a range of other risky activities where people do need to ensure their safety, including hiking around volcanoes, climbing, caving, canyoning, canoeing, being close to wild animals, and thrill-seeking activities such as sky diving, bungee jumping, climbing glaciers, and snow skiing. Associated with a range of these activities is the use of alcohol and drugs, which can increase the risks of injury and trauma. The experience of trauma can, of course, give rise to a risk of infectious disease by exposing travelers to local hospitals and medical facilities in countries where infection control practices may be suboptimal [33].

Road travel

Road travel is by far the most risky activity that any traveler can undertake; it is estimated that 1.3 million people die each year as a result of road traffic injuries [37]. These incidents involve cars, trucks, buses, motorcycles, bicycles, and pedestrians. This risk increases for travelers who visit countries where people drive on the “wrong” side of the road, and this includes pedestrians [38].