TRAVEL MEDICINE

Educational Objectives

The goal of this program is to improve the practice of pretravel medical consultation and immunizations, as well as the diagnosis and management of posttravel health problems. After hearing and assimilating this program, the clinician will be better able to:

1. Perform a thorough pretravel health-risk assessment based on a patient’s medical and travel histories, and current trip itinerary.

2. Advise on appropriate travel hygiene and protective interventions against insect exposure and bites that help lower risk of illness during travel.

3. Select and administer necessary pretravel immunizations.

4. Prescribe effective malaria prophylaxis for the patient who plans to travel to malarious regions.

5. Diagnose the underlying cause of posttravel fever.

Summary

Medical history: immunodeficiency — history of HIV infection or AIDS; chemotherapy for malignancy; corticosteroid (especially prednisone ≥20 mg/day or equivalent) for inflammatory or connective-tissue disease; use of disease-modifying antirheumatic drugs, especially tumor necrosis factor (TNF) inhibitors; relative contraindication to use of live viral vaccines; mefloquine — contraindicated if history of psychiatric illness, seizures, or arrhythmias; medications — eg, antibiotics (impair efficacy of live oral typhoid vaccine); allergies or previous adverse reactions to — vaccines; eggs (avoid vaccines for yellow fever, measles-mumps-rubella, and influenza); medications (eg, antibiotics [especially antidiarrhea medications]); immunization history — can assume patient from emerging or developing country has likely not had usual childhood vaccines (cannot boost unprimed host)

Travel history: where patient has been; immunizations received for travel; problems encountered during previous travel (eg, jet lag, altitude sickness, intolerance to medication)

Cautions: pregnancy — best to avoid travel because of risks to fetus associated with immunizations (especially live vaccines), medications (eg, sulfa drugs, fluoroquinolones), and illnesses developed during travel; contact lenses — many Third World countries have severe air pollution that may cause intolerance of contact lenses; traveler should bring eyeglasses, including spare pair (in case of loss or damage)

Trip itinerary: countries and sequence of travel can influence malaria prophylaxis and immunization for yellow fever; patient planning to travel to rural areas (especially if camping) should receive immunization for rabies; plans — dangerous or adventurous activities (patient should obtain evacuation insurance in case trauma occurs); sex with locals or commercial sex workers (talk frankly with patient about sexually transmitted diseases and consequences); exposure to animals (consider prophylaxis for rabies)

Travel Hygiene

Safe foods: cooked and served hot (not at room temperature or cold); fruits that can be peeled (but not already peeled)

Safe beverages: bottled or canned, and not already opened; made with boiled and/or filtered water (tea likely safer than coffee)

Travelers should avoid: tap water; drinking or gargling in shower; ice; food eaten off any surface except clean plates; swimming or wading in fresh water

Precautions against insects: most worrisome mosquitoes (especially malaria-bearing species) feed after dark; travelers in malarious regions should remain indoors at night, with screens on doors and windows and permethrin-treated bed netting when possible; clothing — permethrin-treated clothing recommended (extremely effective at repelling insects and durable [efficacy lasts through many washings]); permethrin-treated clothing commercially available; also extremely easy to treat regular clothing with permethrin; cover up as much skin as possible; skin — apply diethyltoluamide (DEET; 30%-35%); must be replenished regularly (eliminated by sweating); safe for children as well as adults

Pretravel Immunizations

Tetanus: most of US population probably overimmunized for tetanus; in general, primary immunization plus booster shot every 10 yr provides sufficient protection for travel and domestic life; all adults should receive 1 dose of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine for protection against pertussis

Hepatitis A: can immunize for hepatitis A alone or for hepatitis A and B; hepatitis A vaccine — 2 doses recommended, usually at 0 and 6 mo; if patient about to travel, can give at 0 and 1 or 2 mo to get full immunization earlier; hepatitis A and B vaccine (Twinrix) — 3 doses recommended, at 0, 7, and 21 to 30 days

Typhoid: intramuscular (IM) — 1 dose; good for 2 yr; single-dose vials of vaccine recently recalled (due to decreased antigen content; however, not proven ineffective); oral — 4 doses; live bacteria of attenuated Salmonella typhi; efficacy certified for longer period than IM vaccine; avoid in immunocompromised host; patient cannot be on concomitant antibiotics; administration cumbersome (refrigerated doses must be taken every other day, on empty stomach, and with cold beverage)

Polio: may be necessary if traveling to Africa and/or Asia (especially South Asia); if patient previously immunized, one booster dose sufficient; if patient not immune, 3 doses at 0, 1 to 2 mo, and 6 to 12 mo required (accelerated regimen possible if person traveling sooner)

Measles-mumps-rubella: indications — patient born after 1956; <2 doses in past; recommended widely for international travel

Meningococcus: recommended vaccines quadrivalent conjugate (Menactra, Menveo) and quadrivalent polysaccharide (Menomune; recommended for patients >55 yr of age); all extremely effective against 4 of 5 serotypes, but none fully protective against serotype B; reimmunization necessary every 3 to 5 yr; immunization required for travel to Saudi Arabia (eg, Mecca, Medina), Himalayas, and sub-Saharan Africa

Yellow fever: ≈1 in 1 million recipients of vaccine develops clinical yellow fever (fatal in 25%-50% of cases); vaccine protective for 10 yr; Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) websites provide country-specific recommendations for yellow fever vaccination (some areas considered borderline); use with extreme caution in people >65 yr of age; contraindicated in immunocompromised hosts and in patients on prednisone >20 mg/day (or equivalent dose of methotrexate), on TNF inhibitor, or with HIV with CD4 count <200 cells/µL

Rabies: preexposure vaccination recommended for traveler who anticipates animal exposure or sleeping outdoors overnight in country endemic for rabies; vaccine extremely safe; 2 versions derived from human diploid cell or chicken fibroblast tissue culture; 3 doses given at 0, 7, and 14 to 28 days; advise patient that exposure to animal with suspected rabies requires 2 additional doses of vaccine

Japanese B encephalitis: inactivated, tissue culture-based vaccine (Ixiaro) extremely safe and well tolerated; indications for immunization travel to Far East and South Asia (especially regions with rice farming [standing water breeds mosquitoes] and pigs [definitive hosts]), if person to reside in area >30 days; vaccine not certified for persons <18 yr of age; 2 doses given at 0 and 28 days

Common Travel-Related Health Problems

Traveler’s diarrhea (turista): prevention — adherence to precautions for food and water (helpful but not 100% preventive); antibiotic prophylaxis generally not recommended; take bismuth subsalicylate (eg, Bismarex, Bismatrol, Pepto-Bismol); stop antiacid medications (eg, calcium carbonate [eg, Tums], histamine blockers, proton pump inhibitors) because reducing acid content dramatically lowers infective inoculant required to transmit any enteric infection; treatment — includes fluids with salt and glucose, avoidance of milk products, and loperamide (eg, Diamode, Imodium, Kaopectate) for mild diarrhea; antibiotic therapy for 1 to 3 days (azithromycin drug of choice for children; stop medication when diarrhea ceases)

Malaria prophylaxis: mefloquine — 1 tablet/wk; taken 2 wk pretravel through 4 wk posttravel; ≈10% of patients who take drug suffer serious sleep disturbance (marked by frank insomnia, sleep deprivation, and/or strange “Technicolor” dreams); atovaquone/proguanil (Malarone) — almost twice as expensive as mefloquine; 1 tablet/day; started 1 to 2 days pretravel and continued through 1 wk posttravel; much more effective prophylaxis than other medications; indications — risk for malaria minimal at altitude >5000 ft (prophylaxis not required if traveler staying predominantly at this altitude); CDC and WHO websites indicate which countries require malaria prophylaxis; 90% to 95% of prophylaxis administered atovaquone/proguanil because of patient tolerance; doxycycline — also effective but can be problematic; must be taken daily; tends to produce yeast overgrowth; potential for photosensitization

High-altitude illness: prevention — acclimatization (when at ≥8000 ft, allow 2-3 days for red blood cells to acclimate; limit activity for first 2 days; ascend to higher altitudes as tolerated; avoid alcohol for 2 days); acetazolamide (Diamox) effective, but requires dose of 500 to 750 mg twice daily (side effects of frequent urination and odd taste may limit compliance; many people take drug along on travel and take it therapeutically if symptoms of high-altitude intolerance develop, but not prophylactically); recommended regimen 1 day before through ≈2 days at altitude; treatment — if headache and/or significant sleep disturbance occurs, rest and discontinue activity; if symptoms do not improve, descend

Posttravel fever

Acquired in tropics: 2001 study from Australia showed malaria most common cause of fever in travelers returning from tropics; malaria in North Americans returning from Africa almost certainly caused by Plasmodium falciparum and should be considered medical emergency; other causes include respiratory tract infections (RTIs), gastroenteritis, dengue, typhoid, hepatitis A, and rickettsiosis; most avoidable and preventable (except for viral RTIs)

Fatal and treatable infections: falciparum malaria — fatal in North Americans if not diagnosed and treated promptly; if suspected, do peripheral blood smears every 6 to 8 hr until diagnosed or alternative diagnosis established; initiate treatment at first hint that diagnosis falciparum malaria (numerous red blood cells containing ring forms of P falciparum and >1% parasitized); typhoid fever — keep in mind typhoid vaccine not 100% protective; in addition, patient can develop enteric fever caused by Salmonella species or serotype other than S typhi (not covered by vaccine); meningococcal meningitis — vaccine not 100% protective against serotype B; therefore, immunized patient can develop meningitis and/or bacteremia; amebiasis — generally not fatal; however, patient with amebic dysentery can develop toxic megacolon or colon can perforate and lead to peritonitis; liver abscess potentially dangerous (especially if it ruptures), but generally not life threatening; rickettsioses — most infections not life threatening, but typhus potentially fatal; most of these infections diagnosable; however, no specific diagnostic test for rickettsiosis; if patient returns from tropics with somewhat petechial rash and severe headache, treat with tetracycline to cover rickettsial infections while establishing diagnosis

Nonfatal and treatable infections: spotted fever group of rickettsioses (many different types; characterized by fever, chills, and severe headache; treatment with doxycycline improves symptoms within 24-48 hr); enteritis due to salmonella, campylobacter, shigella (diagnosable by stool culture); toxoplasmosis (consider in patient who has been eating raw or undercooked meats); brucellosis; relapsing fever (suspect infection by Borrelia species); schistosomiasis (patient with Katayama fever can develop migratory rash, fever, and systemic problems)

Posttravel diarrhea: if not bloody and patient has no severe abdominal pain or fever, wait to see whether diarrhea resolves (alternative to give patient dose of antibiotic and see whether it resolves); if true dysentery (fever, abdominal pain, polys and/or blood in stool), suspect infection with Entamoeba histolytica, Shigella species, or Salmonella species; turista usually caused by toxigenic Escherichia coli (noninvasive); persistent malabsorptive diarrhea usually caused by Giardia intestinalis (particularly if associated with upper gastrointestinal symptoms [eg, nausea, anorexia, dyspepsia] because G intestinalis lives in duodenum and proximal jejunum; malabsorption of fats and lactose may cause fatty and floating stools)

Posttravel gastrointestinal illness acquired in tropics: persistent diarrhea; passage of worm, eg, roundworm (Ascaris lumbricoides), tapeworm (Taenia species)

Posttravel skin lesions: myiasis (caused by maggots [fly larvae]; most harmless and not capable of deep penetration); cutaneous larval migrans (seen in patients who have walked on beaches with bare feet or sat directly on sand; caused by hookworm larvae excreted by dogs or cats); cutaneous leishmaniasis (tropical ulcer); cellulitis (eg, folliculitis, furunculosis) most common; scabies highly contagious; myiasis and cutaneous larval migrans uncommon

Posttravel mass lesions: echinococcosis — infection caused by larval forms of canine tapeworms, which form cysts in liver and (to lesser extent) in lungs; cysticercosis — infection with larvae of T solium (pork tapeworm), which most commonly form cysts in central nervous system; other organs can also be involved, including skin; neurocysticercosis extremely common in areas of pig farming and poor disposal of human waste; usually presents as headache due to hydrocephalus and seizures; approach to management controversial; however, if patient symptomatic and has multiple viable lesions, treat with albendazole, praziquantel, or both, plus aggressive pretreatment and ongoing treatment with corticosteroids

Eosinophilia: any worm that has migratory tissue or blood phase can give rise to eosinophilia; can be due to, eg, intestinal nematodes, blood-borne filariasis; rash and eosinophilia caused by Loa loa and onchocerciasis; other cases include schistosomiasis and trichinosis

Readings

Ansart S et al: dermatoses in 165 travelers returning from the tropics with skin diseases. Am J Trop Med Hyg 2007 Jan;76(1):184-6; Ansart S et al: Illnesses in travelers returning from the tropics: a prospective study of 622 patients. J Travel Med 2005 Nov-Dec;12(6):312-8; Bazemore AW, Huntington M: The pretravel consultation. Am Fam Physician 2009 Sep 15;80(6):583-90; Diaz JH, Nesbitt LT Jr: Sun exposure behavior and protection: recommendations for travelers. J Travel Med 2013 Mar;20(2):108-18; Gautret P et al: Travel-associated illness in older adults (>60 y). J Travel Med 2012 May-Jun;19(3):169-77; Genton B, D’Acremont V: Malaria prevention in travelers. Infect Dis Clin North Am 2012 Sep;26(3):637-54; House HR, Ehlers JP: Travel-related infections. Emerg Med Clin North Am 2008 May;26(2):499-516, x; Jensenius M et al: Acute and Potentially Life-Threatening Tropical Diseases in Western Travelers — A GeoSentinel Multicenter Study, 1996-2011. Am J Trop Med Hyg 2013 Feb;88(2):397-404; Kollaritsch H et al: Traveler’s Diarrhea. Infect Dis Clin North Am 2012 Sep;26(3):691-706; Maltha J et al: Malaria rapid diagnostic tests in travel medicine. Clin Microbiol Infect 2013 Jan 14 doi: 10.1111/1469-0691.12152 [Epub ahead of print]; Matteelli A et al: Travel-associated sexually transmitted infections: an observational cross-sectional study of the GeoSentinel surveillance database. Lancet Infect Dis 2013 Mar;13(3):205-13; Moore SJ et al: Insect bite prevention. Infect Dis Clin North Am 2012 Sep;26(3):655-73; Noble LM et al: Travel clinic consultation and risk assessment. Infect Dis Clin North Am 2012 Sep;26(3):575-93; O’Brien D et al: Fever in returned travelers: review of hospital admissions for a 3-year period. Clin Infect Dis 2001 Sep 1;33(5):603-9; Rossi IA, Genton B: The reliability of pre-travel history to decide on appropriate counseling and vaccinations: a prospective study. J Travel Med 2012 Sep-Oct;19(5):284-8; Schlaudecker JD et al: Keeping older patients healthy and safe as they travel. J Fam Pract 2013 Jan;62(1):16-23; Shepherd SM, Shoff WH: Immunization in travel medicine. Prim Care 2011 Dec;38(4):643-79, viii; Ustianowski A, Zumla A: Eosinophilia in the returning traveler. Infect Dis Clin North Am 2012 Sep;26(3):781-9; Zumla A et al: Travel medicine. Infect Dis Clin North Am 2012 Sep;26(3):xiii-xvi. doi: 10.1016/j.idc.2012.07.004.

Disclosures

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, Dr. Glew and the planning committee reported nothing to disclose.

Acknowledgements

Dr. Glew was recorded at the 28th Annual Infectious Disease Conference, held December 6-8, 2012, in Seattle, WA, and presented by Providence Regional Medical Center Everett. For information about upcoming CME events presented by Providence Regional Medical Center Everett, please visit their website at www.washington.providence.org. The Audio-Digest Foundation thanks Dr. Glew and Providence Regional Medical Center Everett for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

IM601801

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.

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