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Health Guidelines for Travel Abroad

a CMO, SAC Health System, 250 South G Street, San Bernardino, CA 92410, USA

b Family Medicine Residency Program, Loma Linda University, 1200 California Street, Suite 240 Redlands, CA 92374, USA

Norman Benjamin Fredrick

c Family and Community Medicine and Public Health Sciences, Global Health Center, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA

Leesha Helm

d Department of Family Medicine, Pennsylvania State University College of Medicine, Penn State Health, PGY-3, 500 University Drive, Hershey, PA 17033, USA

Jeffrey Cho

Most travel medical care is provided by patients’ primary care physicians; only 10% of international travelers visit a travel clinic. The main purposes for travel include vacationing, visiting friends and family, business, and for educational purposes. The purposes of the pretravel consultation are to estimate risk and provide recommendations to mitigate risk.

• • Primary care providers manage the majority of travel medical care. The purpose of the pretravel visit are risk assessment and mitigation.
• • Encourage travelers to enroll in the Smart Traveler Enrollment Program for travel advisories.
• • The Centers for Disease Control and Prevention travel website offers destination-specific, point-of-care resources for clinicians and travelers.
• • Travelers who are visiting friends and relatives are a high-risk group.
• • The most common syndromes in returning travelers are gastrointestinal, febrile, and dermatologic.

Introduction

Most travel medical care is provided by patients’ primary care physicians; only 10% of international travelers visit a travel clinic. The main purposes for travel include vacationing, visiting friends and family, business, and for educational purposes.

Pretravel consultation

The purposes of the pretravel consultation are to estimate risk and provide recommendations to mitigate risk.

Traveler background

The initial pretravel assessment should focus on specific aspects regarding the health background of the traveler ( Box 1 ). A full history and physical examination, including a review of immunizations, allergies, medications, and chronic medical conditions should be explored. Special attention and tailored recommendations should be given to those with chronic disease states, including congestive heart failure, diabetes, mental health issues, and immunocompromised states. It is important to note recent hospitalizations and surgeries and to assess the risk associated with traveling after these events. Prior travel history may provide clues regarding intolerance to certain antimalarials or other medications.

Box 1

Risk assessment, medical history.

• • Medications
• • Allergies
• • Immunizations
• • Chronic disease states
• • Mental health
• • Hospitalizations
• • Surgeries
• • Pregnancy or breastfeeding
• • Previous travel
• • Previous use of antimalarials, antibiotics
• • Plans for repeat travel in next 1 to 2 years

Trip itinerary

• • Location
• • Dates and season
• • Activities, mass gatherings
• • Reasons for travel
• • Accommodations
• • Travel insurance

Trip specifics

Review the itinerary of the traveler, including types of travel, the reason for travel, and accommodations. Country-specific risks and travel advisories should be discussed in detail with the traveler by reviewing resources like the Smart Traveler Enrollment Program ( https://step.state.gov/ ) . By assessing these specific aspects, the provider can obtain a wealth of knowledge that can be synthesized to help the traveler manage possible risks.

Travel recommendations to reduce risk

Preparedness for exacerbations of chronic disease states.

Travel can be stressful and demanding for individuals with chronic disease states. Before travel, clinicians should direct travelers to recommendations provided by national associations related to their chronic medical states for travel guidelines. In addition, travelers should be directed to check in with the US embassy or consulate in their area of travel to clarify any restrictions on medications with which they may need to travel.

Travel Insurance and International Health Care

Many health insurances do not provide adequate coverage for international travel, including repatriation and medical evacuation. 1 The following resources can be used to help travelers make a decision regarding the need for travel insurance, travel health insurance, and medical evacuation insurance.

• • Department of State ( www.travel.state.gov )
• • International Association for Medical Assistance to Travelers ( www.iamat.org )

Accessing Local Reputable Medical Facilities

The International Association of Medical Assistance to Travelers maintains a list of clinics available to members: www.iamat.org/doctors_clinics.cfm . In addition, the Joint Commission International maintains a list of accredited, certified health care facilities: www.jointcommissioninternational.org .

Medications for chronic conditions and prevention of disease states specific to regions of travel should be procured before initiation of travel. Individuals with preexisting conditions or allergies should consider wearing a medical alert bracelet or card in their wallet. See Table 1 for a list of suggested travel health kit items.

Table 1

Health kit item checklist

Abbreviation: HIV, human immunodeficiency virus.

Providers should recommend travelers carry documentation of the following:

• • Health insurance, supplemental insurance,
• • Proof of vaccinations,
• • List of medications and preexisting conditions, and
• • Contact card with emergency contact, location of travel, hospitals and clinics, US embassy or consulate number, health care provider contact information.

Important Travel Risks

The World Health Organization has cited that, among deaths in travelers, 18% to 24% are caused by injuries, whereas only 2% are caused by infectious disease. 1

Motor vehicle safety

Among US travelers in foreign countries, motor vehicle accidents are the leading cause of death, making up approximately 27% of all nonnatural deaths in 1 study. 1  Contributing factors include lack of familiarity with infrastructure in the area of traveled, lack of seat belt use, alcohol use, travel fatigue, poor visibility, and increased risk for road-related accidents. 1 Prevention strategies include using seatbelts and child safety seats, avoiding night-time driving, increasing awareness of driving hazards, using helmets when driving motorcycles or motorbikes, avoiding alcohol or cellphone use before or during driving, using marked taxis for travel, avoiding travel in overcrowded buses, and remaining alert while crossing streets. 1

Drowning is the fourth leading cause of death of international US travelers. 1 Avoidance of swimming alone and the use of a life jacket with water-related activities should be encouraged. Swimming should be avoided when local water conditions or currents are unknown and if a traveler has recently used alcohol.

Crime and violence

Of nonnatural death causes in foreign travelers, 21% can be attributed to crime and violence. 1 Clinicians should encourage travelers to familiarize themselves with crime trends in the areas they are traveling to. Information can be accessed from the Overseas Security Advisory Council website ( www.osac.gov ) . Travelers can also familiarize themselves with security updates by accessing the Department of State’s Bureau of Consult Affairs recommendations for travel safety at http://travel.state.gov . Special precaution should be taken to protect against pickpocketing and individuals should attempt to keep money worn under clothing secured to the neck or waist. Travelers should limit traveling alone or at night time, keep all valuables secure, keep all doors and windows locked, use recommended safe modes of transportation, and avoid resistance if confronted in a robbery. The nearest US embassy should be contacted if concerns related to crime, violence, accidents, medical concerns, or specific travel questions arise.

Counterfeit, adulterated, or expired medications

Travelers should be educated about the risks of procuring medications while traveling including but not limited to medication side effects secondary to use of inappropriately compounded medications, counterfeit medications, and use of uncommon medication additives. 1 Clinicians should recommend obtaining all medications before travel to ensure that individuals are using authentic medications with known side effects and appropriate dosing.

Infections While Abroad

Immunizations.

Maintenance of an accurate immunization history is necessary to provide adequate protection for the traveler. Immunization records should be obtained and reviewed and, if unreliable, titers for measles, mumps, rubella, and hepatitis A should be obtained. Sufficient time should be taken before travel to ensure travel-specific vaccines can be administered and appropriate immunity achieved ( Table 2 ). The risks and benefits of immunizations should be discussed. In addition, vaccines with waning immunity should be addressed as well, especially in the case of immunocompromised travelers. Assessing return travel to similar areas with the next 1 to 2 years from the initial trip will help clinicians to assess the need for specific immunizations. Travelers should be given an updated immunization record to travel with. Country-specific recommendations for vaccines can be accessed by clinicians at the Centers for Disease Control and Prevention (CDC) travel website ( https://wwwnc.cdc.gov/travel ).

Table 2

Travel vaccines, including routine vaccines of high priority in travelers

Abbreviations: IM, intramuscularly; MPSV4, meningococcal polysaccharide vaccine.

Several important diseases are transmitted by mosquitos, of which malaria is among the most important. Most of the 1700 cases of malaria diagnosed in the United States annually are among returned travelers. 1 Box 2 outlines strategies for malaria prevention.

Box 2

Strategies to prevent malaria.

• Long-sleeved pants, shirts, and socks
• Permethrin-treated clothing
• Permethrin-treated bed nets
• Mosquito repellants (≥20% DEET)
• Chemoprophylaxis

From dawn to dusk, mosquitoes that transmit Dengue, Yellow Fever, Zika, and Chikungunya are active and bite whereas, from dusk to dawn, mosquitoes that carry malaria, West Nile, and Japanese encephalitis are active. Providers should review the CDC’s Malaria Maps, and Malaria Information by Country Table and take note of the special considerations mentioned on the drug selection guide: https://www.cdc.gov/malaria/travelers/drugs.html .

Antimalarials should always be purchased before travel, because in some countries drugs that are sold may be counterfeit. 1 Clinicians should also warn travelers that if symptoms of malaria occur, including flulike illness while traveling or after returning home, immediate medical attention should be sought. Antimalarials alone do not prevent transmission and should be used in conjunction with preventive measures, including repellants for skin and clothing in addition to appropriate clothing and mosquito netting. 1 , 6

Traveler’s diarrhea

Traveler’s diarrhea often occurs suddenly with loose, frequent stools in about 30% to 70% of travelers. 7 Poor food handling practices are thought to put travelers at highest risk for traveler’s diarrhea. Preventative measures include specific food and beverage selection, frequent handwashing, frequent use of alcohol-based hand sanitizers with greater than 60% alcohol content, and consideration of vaccination against typhoid and hepatitis A. 8 Table 3 contains recommendations for traveler’s diarrhea treatment based on severity.

Table 3

Treatment of traveler’s diarrhea based on severity

Respiratory illness

Respiratory illness occurs in 20% of returning travels, with upper respiratory infections being the most common respiratory illness. Risks include exposures in hotels, cruise ships, aircrafts and tour group. Individuals with comorbidities including asthma and chronic obstructive pulmonary disease are at higher risk for respiratory illnesses. 1 Prevention tips include minimizing contact with individuals with cough or congestive symptoms, frequent handwashing, and vaccination before travel. Viral etiologies such as rhinovirus, are more common causal agents, although coronaviruses (Middle East respiratory syndrome in the Arabian Peninsula) and avian influenza (Asia) should also be included in a clinician’s differential. 1 Viral causes can also put individuals at risk for superimposed bacterial infections.

Bloodborne illness

Travelers should be cautioned against obtaining tattoos and piercings in low-income areas of the world, because the risk of human immunodeficiency virus and hepatitis C transmission secondary to use of unclean needles is high in these areas. 1

Exposure to human immunodeficiency virus

Travelers should be cautioned about the risk of human immunodeficiency virus specifically associated with certain practices, including needle sharing, risky sexual behaviors, or exposure in a health care setting. In the case of health care workers or individuals who plan to be involved with high-risk behaviors, the physician should discuss having postexposure prophylaxis available to them in case of exposure. Preexposure prophylaxis can reduce the risk of human immunodeficiency virus infection by up to 70%. 1 Immediate attention by a physician should be sought out if concern for exposure arises to ensure appropriate counseling and the possible need for postexposure prophylaxis.

Sexual health

Travelers should be cautioned against high-risk sexual activities that may lead to the transmission of sexually transmitted infections, unwanted pregnancy, or bloodborne infections. Consistent contraceptive methods should be used in a traveler who does decide to be sexually active. Health care resources overseas should be provided for travelers, including reputable clinics to seek out if concerns for sexually transmitted infections and/or pregnancy arise.

Venous Thrombosis and Embolism

Travelers at increased risk for development of deep venous thrombosis who are traveling long distances should be advised to walk as often as possible, use appropriately fitted compression stockings that provide 15 to 30 mm Hg at the ankle, hydration, and to perform calf exercises as often as possible. The use of aspirin for deep venous thrombosis prevention is not recommended. 1

When traveling between time zones, travelers can often develop a mismatch between their natural 24-hour circadian rhythm and the time of day. When traveling through more than 3 time zones, sleep-related difficulty, mood changes, mental clarity, and gastrointestinal disturbance can occur with jet lag. During the pretravel assessment, the clinician can discuss this in detail with the traveler and set expectations. Changes to diet and physical activity, sunlight exposure, the use of melatonin and melatonin-receptor analogs, consideration of hypnotic medications with discussion of risks and benefits, and a combination of these therapies can be discussed with the traveler before initiation of travel. Avoidance of alcohol as a sleep aid should be discussed with travelers as well as encouraging hydration during the trip.

Special populations

Immunocompromised travelers.

According to the 2018 CDC Yellow Book, immunocompromised travelers make up 1% to 2% of travelers seen in US travel clinics. 1 The immunocompromised status may be due to a medical condition, medication, or treatment. Common examples are noted in Box 3 .

Box 3

Examples of immunocompromised travelers.

• Chronic oral steroids greater than or equal to 20 mg per day of prednisone or equivalent
• Posttransplant on medication
• Renal failure on dialysis
• Current or recent (<3 months) chemotherapy
• Chronic liver disease
• Human immunodeficiency virus infection with a CD4 count of less than 200
• Autoimmune diagnosis on biologics

Special points to remember for immunocompromised travelers:

• • Response to vaccines may be limited.
• • Live vaccines are contraindicated in severely immunosuppressed individuals.
• • Increased risk of foodborne and waterborne infections ( Salmonella , Shigella , Campylobacter , Giardia , Listeria , and Cryptosporidium ).
• • Avoid swallowing water during water-based activities.
• • Avoid eating raw seafood.

Traveling while pregnant

Key points for pregnant travelers 1 :

• • Obstetric emergencies are sudden and can be life threatening. Having an emergency plan and access to appropriate obstetric care is recommended.
• • Before booking, check with the airline or cruise ship regarding any limitations on travel. Some limit travel based on gestational age.
• • During air travel the cabin is pressurized to 6000 to 8000 feet. This will not affect a fetus in a normal pregnancy, but could cause fetal problems in women with cardiovascular conditions, sickle cell disease, or severe anemia (hemoglobin <8 g/dL).
• • During air travel, frequent stretching, walking, and isometric exercises are recommended to decrease risk of deep venous thrombosis, which is increased in pregnancy.
• • Treatment of choice for traveler’s diarrhea is hydration and, if indicated, azithromycin.
• • Owing to the risk of birth defects, the CDC recommends that pregnant women do not travel to areas where Zika is present. If travel cannot be avoided, avoidance of mosquito bites is extremely important. More information can be found at the CDC Zika website ( http://www.cdc.gov/zika/pregnancy/index.html ).
• • Most live virus vaccines are contraindicated during pregnancy except for yellow fever, for which pregnancy is considered a precaution by the Advisory Committee on Immunization Practices.
• • Malaria is more serious in pregnant than in nonpregnant women and puts both the mother and the fetus at risk. Malaria chemoprophylaxis is highly encouraged. Chloroquine and mefloquine (depending on the region) are the drugs of choice. Doxycycline and primaquine are contraindicated due to possible effects on the fetus, whereas atovaquone-proguanil lacks available safety data.

Traveling with Children

According to the CDC, an estimated 1.9 million American children travel internationally each year. 1 Typically, children are exposed to the same risks as adults, but the consequences can be more severe and children are less likely to receive travel advice than adults.

The most common health problems among child travelers were 1 :

• • Diarrheal illnesses,
• • Dermatologic diagnosis (animal/insect bites, cutaneous larva migrans, sunburn),
• • Febrile illnesses (malaria), and
• • Respiratory disorders.

Key points when traveling with children 1 :

• • Diarrheal diseases are more common and can be more likely to cause dehydration. Treatment should focus on oral rehydration solution and if indicated antibiotics for traveler’s diarrhea. Children should be given a nonfluoroquinolone such as azithromycin, which can be given as a single daily dose (10 mg/kg) for 3 days.
• • Car crashes and drowning are the leading 2 causes of death in children while traveling. Car seats are often not available so parents should bring their own. Life vests should always be used around water.
• • Avoidance of mosquito and other bug bites is critical, especially in malaria endemic areas. Repellents with DEET should not be used on infants less than 2 months and after 2 months, only repellents with 30% or less DEET should be used.
• • Malaria prophylaxis is also recommended for children in malaria endemic areas. Dosing will need to be adjusted based on weight. Doxycycline should not be given to children less than 8 years old because of the risk of teeth staining, and atovaquone-proguanil should not be used in children weighing less than 5 kg.
• • Rabies is more common in children owing to less fear in approaching animals. If there is exposure to any animal bite, seek medical care immediately. Consider rabies vaccine if planning to spend more than 3 months in endemic area.

Visiting Friends and Relatives

A traveler who is returning home to visit friends or relatives is considered a visiting friends and relatives traveler. Today, visiting friends and relatives travelers make up more than one-half of all international travelers. 1 They are least likely to seek pretravel advice and more likely to develop problems while traveling because they typically stay longer at a destination, eat local food in people’s homes, and often do not take the same precautions as other travelers.

Key points for visiting friends and relatives travelers 1 :

• • Malaria risk is 8 to 10 times higher than for a non-visiting friends and relatives traveler. Malaria immunity weans after living outside of a malaria endemic region, so when returning to the endemic region, malaria prophylaxis and mosquito bite avoidance is recommended. Malaria prevention medication should be started several weeks before international travel.
• • Foodborne illnesses are more common and any immunity to local bacteria can also wean with time after living outside the community. Avoidance of food at room temperature, raw fruits and vegetables, tap water, and ice from tap water is recommended.
• • These travelers are also at increased risk of tuberculosis and sexually transmitted diseases.

Posttravel assessment

General approach.

Worldwide, 8% of travelers develop illnesses severe enough to seek a health care provider. 1 The majority of travelers present to primary care for posttravel illnesses. Data gathered from a directed history can elucidate the cause of a traveler’s symptoms. Knowledge of the travel itinerary and incubation periods is essential to narrowing down a differential diagnosis based on geography and timing after travel.

Common Syndromes

According to a large-scale study by GeoSentinal, a global surveillance network, the most common syndromes in returned travelers are gastrointestinal (34.0%), febrile (23.3%), and dermatologic (19.5%). 9

Gastrointestinal Illness

Many cases of traveler’s diarrhea can be treated empirically, and 80% to 90% of cases are bacterial. See Table 4 for top infectious causes of persistent traveler’s diarrhea. Azithromycin should be preferentially used in travelers returning from South and Southeast Asia owing to the increasing resistance to fluoroquinolones. 7 Severe symptoms, including fever, tenesmus, and gross blood, should prompt further testing, including stool culture. If stool is tested for ova and parasites, 3 or more stool specimens should be collected to increase sensitivity. 7 Some organisms, such as Cryptosporidium and Cyclospora , require specific testing. Testing for Clostridium difficile should be performed if the traveler recently used antibiotics or malaria chemoprophylaxis. A minority of travelers have persistent diarrhea lasting more than 2 weeks, which can be from (1) persistent infection or an untreated coinfection, (2) postinfectious processes like postinfectious irritable bowel syndrome, which can be diagnosed using the Rome criteria, or (3) unmasking of a previously undiagnosed gastrointestinal disease. 7

Table 4

Top infectious causes of persistent traveler’s diarrhea listed in decreasing order of frequency in each column

Febrile Illness

Fever in a returned traveler needs to be evaluated immediately owing to the potential for a rapidly progressing, life-threatening illness like malaria. Those who arrive from areas where malaria is endemic should be evaluated with thick and thin blood films and malarial antigen tests, if available. Blood smears should be repeated if suspicion is high and initial smears are negative. Other important causes to consider include dengue fever, enteric fever (typhoid, paratyphoid), and rickettsial diseases (eg, African tick bite fever), among others. It is also important to keep in mind other common causes of fever including influenza, which occurs year round in tropical climates. See Table 5 for the top febrile illnesses to consider in returned travelers based on location. Those with fever accompanied by alarming symptoms should be thoroughly evaluated as soon as possible, which may be best conducted in the emergency department. In 25% to 40% of patients with fever, no specific cause was identified. 9 , 10

Table 5

Top febrile illnesses to consider in returned travelers based on location

Dermatologic Conditions

Rashes are common in returned travelers. One of the most common skin findings is the classic pruritic migratory serpiginous rash of cutaneous larva migrans. 11 Exposure occurs when skin (eg, bare feet) comes in contact with contaminated sand or soil. Animal bites and scratches, most commonly received from dogs and monkeys, are also common in returned travelers and may require rabies postexposure prophylaxis in up to 12% of cases. 9 See Box 4 for the top tropical dermatologic conditions to consider in returned travelers.

Box 4

Top 10 tropicala dermatologic conditions to consider in returned travelers.

• 1. Cutaneous larva migrans
• 2. Arthropod bite
• 3. Myiasis (bot fly, tumbu fly)
• 4. Injuries including animal bites
• 6. Cutaneous leishmaniasis
• 7. Tungiasis
• 8. Swimmer’s itch
• 9. Rickettsial infection
• 10. Dengue fever

a Many cosmopolitan causes (eg, cellulitis) excluded from this list.

Screening Asymptomatic Returned Travelers

Currently, there are no CDC guidelines for asymptomatic returned travelers.

Special circumstances section

Altitude illness.

Altitude illness is most common at altitudes of 8200 feet (2500 m) or more, although it can occur at lower elevations. 1 The main issue in altitude sickness is hypoxemia, which is exacerbated during sleep. Respiratory depressants such as alcohol and sleep medications should be avoided; acetazolamide and stimulants may speed acclimatization. Moderate-to-vigorous physical activity can exacerbate hypoxemia and should be avoided for the first 48 hours. Physical conditioning does not predict acclimatization. Contraindications to traveling to altitude include severe heart or lung disease, sickle cell anemia, high-risk pregnancy, and cerebral pathology.

There are 3 altitude syndromes: acute mountain sickness, high altitude cerebral edema, and high altitude pulmonary edema. Treatment involves immediate descent, medications ( Table 6 ), oxygen supplementation, and pressurization bags if rapid descent is not feasible.

Table 6

Common medications for altitude illness

Abbreviations: AMS, acute mountain sickness; BID, twice per day; HACE, high altitude cerebral edema; HAPE, high altitude pulmonary edema; PO, by mouth.

SCUBA Diving

SCUBA-related illnesses can be divided into 2 categories: barotrauma and decompression illness. The primary risk factors are dive depth, bottom time, and speed of ascent. 1 Decompression illness can occur even when all precautions are taken. The Divers Alert Network is a resource that can be accessed by both divers and health care providers at http://www.diversalertnetwork.org/ or at their 24-hour emergency hotline (919-684-9111).

Motion Sickness

Motion sickness is not a true pathology, but a normal response to the external stimulation that is created by the vestibular system. The most common forms are sea sickness, motor vehicle sickness, and air sickness. It has been noted to be more common in women and less common in frequent travelers either owing to habituation or self-selection. See Box 5 and Table 7 for recommendations for motion sickness prevention and management.

Box 5

Recommendations to prevent motion sickness, table 7.

Common preventive medications for motion sickness

Abbreviation: PO, by mouth.

Mass Gatherings

Defined as at least 1000, but can be more than 25,000, people gathered at a specific location for a specific purpose. 1 Often these gatherings can strain the local resources and increase the risk of disease transmission among the attendees. Common challenges among attendees are hypothermia, heat exhaustion, dehydration, sunburn, but worsening of underlying chronic diseases (eg, heart failure, diabetes) also occurs. And at times there can be other dangers such as unsafe transportation, stampedes, collapse of structures, fire, terrorism and other forms of violence. See Box 6 for examples of mass gatherings.

Box 6

Mass gathering examples.

• Measles exposure at amusement parks in the United States.
• Meningitis (meningococcal vaccine is required for the Hajj) and respiratory infections (Coronavirus) among Hajj pilgrims.
• Concern for Zika at Rio, Brazil Olympics.
• Exposure to flu during sports events, concerts, conventions.

Disclosure Statement: The authors have nothing to disclose.

CHRISTOPHER SANFORD, MD, MPH, ADAM MCCONNELL, MD, AND JUSTIN OSBORN, MD

Am Fam Physician. 2016;94(8):620-627

Patient information : See related handout on tips for international travel .

Author disclosure: No relevant financial affiliations.

Key components of the pretravel consultation include intake questions regarding the traveler's anticipated itinerary and medical history; immunizations; malaria prophylaxis; and personal protection measures against arthropod bites, traveler's diarrhea, and injury. Most vaccinations that are appropriate for international travelers are included in the routine domestic immunization schedule; only a few travel-specific vaccines must also be discussed. The most common vaccine-preventable illnesses in international travelers are influenza and hepatitis A. Malaria prophylaxis should be offered to travelers to endemic regions. Personal protection measures, such as applying an effective insect repellent to exposed skin and permethrin to clothing and using a permethrin-impregnated bed net, should be advised for travelers to the tropics. Clinicians should offer an antibiotic prescription that travelers can take with them in case of traveler's diarrhea. Additional topics to address during the pretravel consultation include the risk of injury from motor vehicle crashes and travel-specific risks such as altitude sickness, safe sex practices, and emergency medical evacuation insurance.

Data show that 1.1 billion persons crossed an international border in 2014, and this number is projected to increase to 1.8 billion persons in 2025. 1 Tourism is increasing in both high- and low-income destinations, and is the first- or second-largest source of revenue in 20 of the 48 least developed countries. 2

WHAT'S NEW ON THIS TOPIC: THE PRETRAVEL CONSULTATION

Pregnant women and women of childbearing age who are trying to conceive should postpone travel to Zika-endemic areas. If they do visit these areas, they should be vigilant about arthropod avoidance measures. Because Zika is also transmitted by sex, men who visit Zika-endemic areas should use condoms with pregnant sex partners.

Only a minority of international travelers—36% in one study—seek pretravel counseling; of those, 60% see a primary care clinician, 10% see a travel subspecialist, and 30% turn to friends and family. 3 Although research supports some portions of the pretravel encounter (e.g., malaria prophylaxis, immunizations), the benefit of counseling on other topics (e.g., motor vehicle crashes, safe sex) has not yet been demonstrated. 4

Although consulting a clinician is beneficial to patients at any time before international travel, pretravel visits should ideally occur at least six weeks before departure to maximize benefit of immunizations and other preventive measures. The pretravel consultation is likely to be particularly useful in those visiting low-income nations.

Table 1 outlines the recommended components of the pretravel consultation, 5 , 6 and Table 2 provides resources for clinicians who provide pretravel services. Physicians who perform pretravel consultations only occasionally or who have minimal training in travel medicine may want to refer complex cases to a clinician experienced in travel medicine.

The assessment should include dates of travel, anticipated itinerary, planned activities, mode of travel, and reason for travel. Additionally, clinicians should inquire about the traveler's acceptance level for health risks and budget for health care expenditures.

A full medical history should be elicited from the traveler, including immunization records, medications, allergies, and medical conditions. Certain conditions, if uncontrolled, may increase health risks in travelers and include congestive heart failure, hypertension, seizures, diabetes mellitus, and mental illness. Clinicians may recommend against particular trips or activities if they exceed the traveler's physical abilities or if there is a specific contraindication. Persons who have had a myocardial infarction or coronary artery bypass within the previous two weeks, or a complicated myocardial infarction within the previous six weeks, 7 are thought to be at higher risk of cardiovascular events when flying. Prior use of antimalarials and any adverse effects experienced should be recorded. Physicians should ask women about pregnancy status and birth control method, if applicable.

Selected travel hazards and risk reduction strategies are included in Table 3 . 8 – 12

Noninfectious Risks

The most common cause of death in nonelderly international travelers is motor vehicle crashes, which account for 18% to 24% of deaths in all travelers. Deaths from motor vehicle crashes are markedly more common in low-income nations. Other common causes of death in travelers include violence (e.g., homicide, suicide) and drowning. 13 , 14

Immunization-Preventable Diseases

eTable A summarizes immunizations recommended for international travelers. Live vaccines should be avoided in travelers who are pregnant or immunocompromised.

ROUTINE VACCINES

In general, the diseases on the routine domestic immunization schedule are more common in travelers than are the travel-specific illnesses; hence, travelers should be up to date on the routine vaccines recommended by the Advisory Committee on Immunization Practices. The most common vaccine-preventable illnesses in international travelers are influenza and hepatitis A. The influenza season is between April and September in the southern hemisphere, and it occurs year-round in locations near the equator. Immunization for influenza should be advised when available. Hepatitis A, transmitted by contaminated food and water, is ubiquitous in low-income nations, and the vaccine is appropriate for all travelers older than one year. 15

TRAVEL-SPECIFIC VACCINES

Travel-specific immunizations include those for typhoid fever, 16 yellow fever, Japanese encephalitis, rabies, and cholera. Travelers may be required to show proof of vaccination for yellow fever to enter or return from nations within endemic regions (tropical Africa and tropical South America). Physicians should document yellow fever vaccination on travelers' International Certificate of Vaccination or Prophylaxis (“yellow card,” as approved by the World Health Organization). An example of the vaccine certificate is available at http://www.who.int/ihr/IVC200_06_26.pdf?ua=1 . If travelers have a contraindication to the yellow fever immunization, clinicians should write a letter of exemption or complete the waiver section of the vaccine certificate; these are generally accepted at international borders. Travelers to Saudi Arabia for the annual hajj and umrah (Muslim pilgrimage) are required to show proof of immunization for meningococcal meningitis.

Protection Against Insects and Other Arthropods

Personal protection measures.

It is important to stress to travelers that taking antimalarials does not negate the need for personal protection measures ( Table 4 17 ) , which guard against malaria and numerous other arthropod-borne diseases (e.g., dengue fever, a common illness in most tropical countries). 18 , 19

Insect repellent should be applied to exposed skin. The most effective insect repellents contain 20% to 50% diethyltoluamide (DEET) 20 , 21 or 20% picaridin. Other effective insect repellents are oil of lemon eucalyptus (PMD) and IR3535. Insect repellent should not be applied onto or under clothing. Regular reapplication is important.

Applying permethrin to clothing markedly increases protection against insect bites. 22 , 23 Travelers to malaria-endemic regions should sleep under a bed net impregnated with permethrin unless there is air-conditioning. Wearing long sleeves and pants offers additional protection. The vector for malaria is the female Anopheles mosquito, which feeds at dusk, nighttime, and dawn; minimizing time outdoors during these times will reduce risk. IR3535 does not provide adequate protection against Anopheles mosquitoes and should not be used in malaria-endemic areas.

MALARIA PROPHYLAXIS

Travelers to endemic regions should receive malaria prophylaxis. 24 , 25 The choice of prophylactic medication ( Table 5 20 , 26 ) should be based on whether the patient is going to an area with chloroquine-sensitive or chloroquine-resistant malaria, whether there could be potential adverse effects or interactions with the patient's medical conditions or other medications, the convenience of dosing schedule, and the cost. A summary of countries where malaria is endemic and prophylaxis recommendations from the Centers for Disease Control and Prevention are available at http://www.cdc.gov/malaria/travelers/country_table/a.html . Recommendations from the World Health Organization are available at http://www.who.int/ith/2015-ith-chapter7.pdf?ua=1 .

Regions where chloroquine-sensitive malaria is endemic include Mexico and Central America (west of the Panama Canal), and the island of Hispaniola (Haiti and the Dominican Republic). Options for prophylaxis in these regions are chloroquine (Aralen) and hydroxychloroquine (Plaquenil). Potential adverse effects of these medications include blurred vision, headache, nausea, and vomiting. Hydroxychloroquine may be better tolerated than chloroquine. Primaquine may be used for prophylaxis in areas affected primarily by Plasmodium vivax malaria.

The options for travelers to chloroquine-resistant regions (including most of South America, Asia, and Africa) are doxycycline, atovaquone/proguanil (Malarone), and mefloquine; these agents are equally effective. Doxycycline, which is taken daily, is relatively inexpensive. Potential adverse effects include nausea, photosensitivity, vaginal yeast infections, and esophageal ulceration. Atovaquone/proguanil, also a daily medication, is the most expensive option but has the lowest incidence of adverse effects. Mefloquine, taken weekly, is well-tolerated by most patients, but has a U.S. Food and Drug Administration boxed warning because of its neurologic and psychiatric adverse effects. In some areas of Southeast Asia, malaria is resistant to mefloquine, and doxycycline or atovaquone/proguanil should be used. Antimalarials should not be purchased in low-income nations because there is a high risk of counterfeit, adulterated, or expired medications.

ZIKA VIRUS INFECTION

Zika virus infection is primarily transmitted by mosquitoes, but it can also be sexually transmitted. Since May of 2015, this disease has spread to Mexico and essentially every country in Central and South America and the Caribbean. Risk of microcephaly in the newborn if a woman is infected in the first trimester of pregnancy has been estimated at 1% to 13%. Pregnant women should avoid travel to areas with Zika transmission. Men who live in or visit a Zika-endemic area should use a condom or abstain from sex with a pregnant partner for the remainder of the pregnancy. 27 , 28

Traveler's Diarrhea

Traveler's diarrhea (TD) is by far the most common infection in international travelers, with a rate of 30% to 70% depending on destination and season of travel. The risk is highest in the first two weeks of travel and slowly declines thereafter. 29 Taking medications that reduce gastric acidity, including proton pump inhibitors and antacids, significantly increases the risk of TD. 10 Other risk factors include younger age, diabetes, and immunosuppression.

The etiology of TD is bacterial in 80% to 90% of cases; the remainder are caused by viral or protozoan organisms. Bacterial and viral TD usually present as the sudden onset of loose stools, cramping, and nausea. Other manifestations may include abdominal pain, fever, vomiting, and bloody stools. TD caused by protozoan organisms, such as Giardia , tends to have a more insidious onset and a longer duration of symptoms. 30

Traditional advice (e.g., avoiding food from street stands, tap water, raw foods, and ice) has not been shown to reduce the incidence of TD. 31 Hand washing reduces risk by 30%; alcohol-based hand sanitizer also significantly reduces risk. 32

Prophylactic antibiotics are not routinely recommended. For patients at particularly high risk, taking bismuth subsalicylate (Pepto-Bismol; two tablets four times daily for the duration of the trip) reduces risk by 50% to 65%. 20 , 33 Possible adverse effects of bismuth subsalicylate include a black tongue and dark stool, and contraindications include aspirin allergy, renal insufficiency, breastfeeding, and concurrent use of anticoagulants. There is insufficient evidence for the use of probiotics to prevent TD.

The primary supportive treatment for TD is rehydration. However, in general, TD is not dehydrating, except for in persons who are very young or old or who have chronic illnesses. If dehydration occurs, travelers can rehydrate with most fluids, including water, juice, soda pop, or tea.

Loperamide (Imodium) is a safe and effective antimotility agent that can be used with or without antibiotics. It should be avoided in persons with warning signs, such as blood in the stool or fever, and in children younger than six years. Diphenoxylate is an alternative antimotility agent.

Without treatment, TD usually lasts three to seven days. A short course of antibiotics usually shortens symptom duration to six to 24 hours. 34 , 35 Fluoroquinolones are effective for self-treatment of TD in Africa and Latin America. One regimen is ciprofloxacin taken as one 500-mg tablet followed by a second 500-mg tablet 12 hours later. However, a macrolide, such as azithromycin (Zithromax; 500 mg daily for one to three days or one 1,000-mg tablet [higher incidence of nausea]) is more effective in South and Southeast Asia because of the high prevalence of TD caused by fluoroquinolone-resistant Campylobacter . Given the recent warning by the U.S. Food and Drug Administration regarding adverse effects of fluoroquinolones, 36 clinicians may consider prescribing a macrolide for self treatment of TD regardless of destination. Rifaximin (Xifaxan), an antibiotic with minimal systemic absorption, can be used as a preventive medication (200 mg once or twice daily) or as treatment (200 mg three times daily for three days). It is not approved by the U.S. Food and Drug Administration for TD prophylaxis.

Because TD is usually self-limited, and antibiotics have potential adverse effects, a course of carry-along antibiotics should be prescribed for the patient to use only if needed. To reduce the risk of creating drug-resistant bacteria, antibiotics should be taken only for severe diarrhea. 37

Travelers with TD who develop syncope, dehydration, or symptoms lasting more than one week should seek medical care. Studies show that 3% to 17% of TD cases may result in chronic postinfectious irritable bowel syndrome; the risk increases with multiple bouts of TD. 38 , 39

Emergency Medical Evacuation Insurance

Emergent medical evacuation from a low-income nation can cost $50,000 to $75,000 or more. Emergency medical evacuation insurance is particularly important for older travelers, for those with chronic medical conditions, and for those engaged in high-risk activities, such as high-altitude climbing. Travelers can visit https://www.squaremouth.com/ to compare travel insurance options, including medical and emergency evacuation insurance.

Travelers with Chronic Medical Conditions

Persons with most medical conditions can travel without restriction, but additional advance preparation may be necessary. Medical conditions should be stable before travel, and patients requiring frequent medical interventions should postpone travel to low-income nations.

Travelers who have chronic medical conditions should carry a list of their medications and physician contact information. Medications should be transported in carry-on, not checked, luggage and remain in the labeled containers in which they were dispensed from the pharmacy. Travelers who have diabetes should accept somewhat higher than usual glucose values during travel days to avoid hypoglycemia. Those requiring oxygen should contact the airline several weeks in advance to arrange for oxygen during flights. The Federal Aviation Administration does not allow passengers to carry their own oxygen tanks; battery-powered portable oxygen concentrators approved by the Department of Transportation may be used. Travelers who have a significant history of cardiac events should travel with a recent electrocardiogram.

Pregnant Women

Most airlines allow pregnant women to fly until 36 weeks of gestation. Pregnant women should not scuba dive because of the potential risk of decompression sickness in the fetus and fetal malformations. 40

Data Sources: We searched PubMed, the Cochrane Database of Systematic Reviews, Essential Evidence Plus, AHRQ Evidence Reports, and BMJ Clinical Evidence. Key words: travel medicine, immunizations, malaria prophylaxis, traveler's diarrhea, motor vehicle injuries, pretravel consultation. Search dates: May and September 2015, and June 2016.

note: This review updates previous articles by Bazemore and Huntington , 26 Lo Re and Guzman , 41 and Dick . 42

World Travel and Tourism Council. http://www.wttc.org . Accessed June 2015.

World Tourism Organization Network. http://step.unwto.org/content/tourism-and-poverty-alleviation-1 . Accessed June 27, 2015.

Hamer DH, Connor BA. Travel health knowledge, attitudes and practices among United States travelers. J Travel Med. 2004;11(1):23-26.

Talbot EA, Chen LH, Sanford C, et al. Travel medicine research priorities: establishing an evidence base. J Travel Med. 2010;17(6):410-415.

Travel and Tropical Medicine Manual . St. Louis, Mo.: Elsevier; 2016.

Pottinger PS, Sanford CA. Travel and adventure medicine. Med Clin North Am. 2016;100(2):xvii-xviii.

Aerospace Medical Association. http://www.asma.org . Accessed Feb. 2016.

Sanford C. Urban medicine: threats to health of travelers to developing world cities. J Travel Med. 2004;11(5):313-327.

Paulozzi LJ, Ryan GW, Espitia-Hardeman VE, Xi Y. Economic development's effect on road transport-related mortality among different types of road users. Accid Anal Prev. 2007;39(3):606-617.

Ehiri JE, Ejere HO, Magnussen L, Emusu D, King W, Osberg JS. Interventions for promoting booster seat use in four to eight year olds traveling in motor vehicles. Cochrane Database Syst Rev. 2006;1:CD004334.

Vivancos R, et al. Foreign travel associated with increased sexual risk-taking, alcohol and drug use among UK university students. Int J STD AIDS. 2010;21(1):46-51.

Kahn SR, Lim W, Dunn AS, et al. Prevention of VTE in nonsurgical patients. 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2 suppl):e195S-e226S.

Cortés LM, et al. Recommendations for water safety and drowning prevention for travelers. J Travel Med. 2006;13(1):21-34.

Tonellato DJ, et al. Injury deaths of US citizens abroad. J Travel Med. 2009;16(5):304-310.

Innis BL, Snitbhan R, Kunasol P, et al. Protection against hepatitis A by an inactivated vaccine. JAMA. 1994;271(17):1328-1334.

Anwar E, Goldberg E, Fraser A, et al. Vaccines for preventing typhoid fever. Cochrane Database Syst Rev. 2014;1:CD001261.

Yates J. Advice for protection against mosquitoes and ticks [editorial]. Am Fam Physician. 2015;91(11):754-755.

Alpern JD, et al. Personal protection measures against mosquitoes, ticks, and other arthropods. Med Clin North Am. 2016;100(2):303-316.

Hill DR, et al.; Infectious Diseases Society of America. The practice of travel medicine. Clin Infect Dis. 2006;43(12):1499-1539.

Brunette GW, Kozarsky PE, Cohen NJ. CDC Health Information for International Travel 2016 . New York, NY: Oxford University Press; 2016.

Schoepke A, et al. Effectiveness of personal protection measures against mosquito bites for malaria prophylaxis in travelers. J Travel Med. 1998;5(4):188-192.

Banks SD, et al. Insecticide-treated clothes for the control of vector-borne diseases. Med Vet Entomol. 2014;28(suppl 1):14-25.

Rowland M, Durrani N, Hewitt S, et al. Permethrin-treated chaddars and top-sheets. Trans R Soc Trop Med Hyg. 1999;93(5):465-472.

Schlagenhauf P, Weld L, Goorhuis A, et al. Travel-associated infection presenting in Europe (2008–12) [published correction appears in Lancet . 2015;15(3):263]. Lancet Infect Dis. 2015;15(1):55-64.

Lüthi B, Schlagenhauf P. Risk factors associated with malaria deaths in travellers: a literature review. Travel Med Infect Dis. 2015;13(1):48-60.

Bazemore AW, Huntington M. The pretravel consultation. Am Fam Physician. 2009;80(6):583-590.

Johansson MA, et al. Zika and the risk of microcephaly [published ahead of print May 25, 2016]. N Engl J Med . http://www.nejm.org/doi/full/10.1056/NEJMp1605367 . Accessed June 30, 2016.

CDC. Zika virus. http://www.cdc.gov/zika/ . Accessed June 13, 2016.

Kollaritsch H, Paulke-Korinek M, Wiedermann U. Traveler's diarrhea. Infect Dis Clin North Am. 2012;26(3):691-706.

Ortega YR, Adam RD. Giardia. Clin Infect Dis. 1997;25(3):545-549.

Steffen R, Tornieporth N, Clemens SA, et al. Epidemiology of travelers' diarrhea: details of a global survey. J Travel Med. 2004;11(4):231-237.

Henriey D, et al. Does the use of alcohol-based hand gel sanitizer reduce travellers' diarrhea and gastrointestinal upset?. Travel Med Infect Dis. 2014;12(5):494-498.

Ericsson CD. Nonantimicrobial agents in the prevention and treatment of traveler's diarrhea. Clin Infect Dis. 2005;41(suppl 8):S557-S563.

De Bruyn G, Hahn S, Borwick A. Antibiotic treatment for travellers' diarrhoea. Cochrane Database Syst Rev. 2000;3:CD002242.

Heather CS. Travellers' diarrhoea. BMJ Clin Evid . April 30, 2015. http://clinicalevidence.bmj.com/x/systematic-review/0901/overview.html . April 30, 2015. Accessed September 20, 2015.

U.S. Food and Drug Administration. FDA advises restricting fluoroquinolone antibiotic use for certain uncomplicated infections; warns about disabling side effects that can occur together. http://www.fda.gov/Drugs/DrugSafety/ucm500143.htm . Accessed August 29, 2016.

Kantele A, Lääveri T, Mero S, et al. Antimicrobials increase travelers' risk of colonization by extended-spectrum betalactamase-producing Enterobacteriaceae. Clin Infect Dis. 2015;60(6):837-846.

Nair P, et al. Persistent abdominal symptoms in US adults after short-term stay in Mexico. J Travel Med. 2014;21(3):153-158.

Connor BA, Riddle MS. Postinfectious sequelae of travelers' diarrhea. J Travel Med. 2013;20(5):303-312.

Stewart BT, et al. Road traffic and other unintentional injuries among travelers to developing countries. Med Clin North Am. 2016;100(2):331-343.

Lo Re V, Gluckman SJ. Travel immunizations. Am Fam Physicians. 2004;70(1):89-99.

Dick L. Travel medicine: helping patients prepare for trips abroad. Am Fam Physicians. 1998;58(2):383-398.

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Gearing up for the travel season : how clinicians can ensure their patients are packed with knowledge on Zika prevention

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December 8, 2016

• Series: COCA Conference Call
• Personal Author: Tanner, Mary ; Walker, Allison Taylor Tanner, Mary ; Walker, Allison Taylor Less -
• Corporate Authors: Centers for Disease Control and Prevention (U.S.). Office of Public Health Preparedness and Response. Division of Emergency Operations. ; National Center of Emerging and Zoonotic Infectious Diseases (U.S.). Division of Global Migration and Quarantine. Travelers’ Health Branch. Centers for Disease Control and Prevention (U.S.). Office of Public Health Preparedness and Response. Division of Emergency Operations. ; National Center of Emerging and Zoonotic Infectious Diseases (U.S.). Division of Global Migration and Quarantine. Travelers’ Health Branch. Less -
• Description: Clinician Outreach and Communication Activity (COCA) conference call Thursday, December 8, 2016 Throughout this holiday season, many clinicians will see patients who plan to travel or have recently traveled to areas with active Zika transmission. During this COCA Call, clinicians will learn about current CDC travel recommendations, how to determine which patients should receive Zika testing after traveling to an area with Zika, and the recommendations for patients before and after travel to help them protect themselves and others from Zika. More ▼ -->
• Subjects: [+] Travel Zika Virus Infection
• Series: COCA Conference Call ; CDC's response to Zika COCA Conference Call ; CDC's response to Zika Less -
• Document Type: Presentation
• Collection(s): Stephen B. Thacker CDC Library collection
• Main Document Checksum: [+] urn:sha256:b8f539fd576d3e69e5be512c5859b8ca8d3b4bc248367c5f8e0ab1ec279c8558
• Download URL: https://stacks.cdc.gov/view/cdc/44141/cdc_44141_DS1.pdf

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Clinical Guidance for Heat and Cardiovascular Disease

• Encourage your patients with cardiovascular disease (CVD) to check the HeatRisk  forecast daily during warm months and take protective action when HeatRisk is orange or higher, since heat can worsen cardiovascular disease.
• There are several ways to stay healthy when it’s hot outside. Create a Heat Action Plan  with your patients with CVD.
• Hot days can worsen air quality and breathing polluted air can increase the risk of heart attacks, strokes, arrhythmias, and worsen heart failure. Exposure to increased concentrations of fine particulate matter over just a few hours to weeks can trigger cardiac events and CVD-related death.
• Because of the risk of CVD events associated with air pollution, encourage patients with CVD to also check the air quality index  (AQI) daily and take protective action when the AQI is >100.
• Review medications commonly prescribed for cardiovascular disease, such as some antihypertensive agents, which may increase heat sensitivity. Periodic review of medications and patient education on risk reduction before and during the heat season may prevent harm.
• Risk factors
• Patient management

This guidance document is intended to help support your conversations with your patients with cardiovascular disease (CVD) on the impact of heat on CVD. The information provided can empower them to take protective actions on hot days. While not everyone may be able to take all actions, each action can help your patients stay healthy during hot days.

Heat and cardiovascular disease

Being outside can be good for the health of your patients. Exposure to heat, however, can lead to a range of heat-related adverse CVD health outcomes, including death. Heat stress can increase demand on the heart and cardiovascular system and promote dehydration, blood clots, and electrolyte imbalances that may all contribute to cardiovascular disease. This can worsen heart failure and precipitate acute coronary syndrome (ACS), acute myocardial infarction (AMI), arrythmias, and stroke, and contribute to excess mortality from these causes. Extremely hot temperatures have been associated with heart failure deaths. The combined effect of humidity and hot temperatures can affect blood pressure and can increase hospitalizations related to CVD.

Heat, air quality, and CVD

Heat can worsen air pollution and air pollution can worsen CVD and trigger cardiovascular events. Air pollution, especially fine particulate matter (PM 2.5 ) but including ozone, sulfur dioxide and other air pollutants, can increase the risk of cardiovascular events such as AMI, arrhythmia, and death.

Hot and dry weather can increase the risk of wildfires, and wildfire smoke can provoke adverse cardiovascular and cerebrovascular events. During the warmest months of the year, exposure to multiple concurrent environmental hazards, including wildfire smoke, pollen, and mold from floods, can amplify risks to cardiovascular health.

Heat, medications, and CVD

Many medications , including medications to manage CVD, and over the counter medications like antihistamines and analgesic medications, can impair heat tolerance and the body’s ability to regulate its temperature. Medications can decrease the body’s ability to sweat, and therefore to cool itself.

This can predispose people to heat illness during hot days.

Antihypertensive medications lower blood pressure and, in the setting of dehydration from heat, may be more likely to contribute to fainting. Antiplatelet drugs, such as aspirin and clopidogrel, can decrease blood vessel dilation and reduce the ability for the body to eliminate heat. Diuretics and heat can both promote electrolyte imbalance and dehydration, which can contribute to CVD risk. Dehydration can increase the risk for kidney injury from medications such as non-steroidal anti-inflammatory drugs (NSAIDs). Dehydration can also increase blood levels of medications which may result in adverse events.

Lastly, many medications, including certain antibiotics, can increase sensitivity of the skin to the sun, and direct heat can degrade or damage certain medications, such as insulin or inhalers used to treat chronic obstructive pulmonary disease.

Attention to heat exposure as a component of medication management for patients with cardiovascular disease may prevent harm. The Heat and Medications page provides more information on medications and heat that can inform patient guidance.    

Take these 5 steps to help your patients stay safe on hot days and document them in a Heat Action Plan  with your patients.

• Ask about baseline status of cardiovascular disease, including blood pressure control and CVD symptoms. Poorly controlled blood pressure or heart disease may increase sensitivity to heat and poor air quality.
• Does your patient have working air conditioning?
• Can they check and control indoor temperatures where they live?
• Do they have an electric fan?
• Do they know how to locate a cooling center if needed?
• Does your patient have stable housing?
• Do they live on a higher floor of a multi-story building where they may be exposed to more heat?
• Are they regularly exposed to indoor air pollutants such as secondhand smoke or mold?
• Do they have a portable air purifier or a filter in their HVAC system?
• Does your patient have a neighbor, friend, or family member who can check on them during hot days?
• Does their mobility limit their ability to seek cooling in their home or elsewhere?
• If heat leads to a power outage, does your patient have a plan for refrigerated medications and/or electric medical devices, such as nebulizer machines, ventilators, or oxygen concentrators?
• Does your patient check the daily and hourly weather forecast to know the hottest time of the day? Can they access the HeatRisk tool?
• Where does your patient get information about how to protect their health from heat and what measures do they take to do so?
• Does your patient take medications that increase risk from heat exposure?
• How much time does your patient spend outdoors on hot days for work, sports, or recreation?
• Are they exposed to outdoor air pollution at home, work, or elsewhere, such as a major roadway, construction site, industrial facility, or frequent wildfire smoke?
• Do they have allergies to grass, weeds, and tree pollens?
• Review the HeatRisk Tool  with your patients which outlines how commonly each color HeatRisk level may occur and provides suggested actions people can take at each color level.
• Some people will be sensitive to heat when HeatRisk is yellow and will need to take action at the yellow level. Ask your patients to monitor their symptoms at HeatRisk yellow and orange and let you know if this applies to them.
• Review the signs of heat-related illness and signs of worsening CVD associated with heat exposure with your patients. Heat symptoms include heavy sweating, muscle cramps, weakness, light headedness, headache, nausea, and vomiting. Develop a plan with them for when to seek medical care.
• Wear light, loose-fitting clothing that covers arms and legs, a hat with a brim that shades the face, ears, and back of the neck, and sunglasses.
• Apply broad spectrum  sunscreen that filters out UVA and UVB rays. The sunscreen should have an SPF of 30 or higher.
• Remind your patients to try to schedule their activities during the coolest time of the day or evening, if possible.
• Use an air conditioner if they have one or find a location that does. Even a few hours in a cool location can lower the risk for health problems from heat.
• Use fans, but only if indoor temperatures are less than 90°F. In temperatures above 90°F, a fan can increase body temperature.
• Refer patients who need assistance with home energy costs to the Low-Income Heat Energy Assistance Program (LIHEAP).
• Direct your patients to information about public resources such as cooling centers, pools, and splash pads. The nearest cooling center locations can be located by calling 2-1-1, checking  public resources , and/or contacting your local health department and emergency management agency.
• Review signs and symptoms of dehydration, which include:

Cold, clammy skin Dizziness or feeling lightheaded Rapid heart rate Excessive sweating or an inability to sweat Fatigue Headache Muscle cramps or spasms

Nausea Abdominal cramping Swelling in extremities Darker color urine Infrequent urination Thirst

• Emphasize the importance of regular and consistent fluid and food intake throughout the day.
• Advise patients to consider limiting beverages higher in sugars, sodium, caffeine, and alcohol, if possible, which may lead to dehydration. See Guideline 4 of the dietary guidelines .
• Advise patients that water is usually the best choice, although sports drinks containing electrolytes may be necessary if sweating for several hours.
• Since patients with CVD may restrict sodium intake, remind them to look at the sodium content of beverages.
• Remind patients with heart failure or kidney disease to monitor for signs and symptoms of fluid overload and dehydration on hot days. Consider fluids with electrolyte supplements as needed.
• Review the Air Quality Index (AQI) with your patients at on the HeatRisk Dashboard , their phone’s weather app, or at airnow.gov . Ensure they know how to access, understand, and use the information including which action steps they can take based on the specific air quality level.

About the Air Quality Index (AQI) and Actions to Consider at Each Level

The AQI reports air quality for common air pollutants such as ground-level ozone, particle pollution, carbon monoxide, sulfur dioxide, and nitrogen dioxide. Its value ranges from 1 to 500, with higher numbers corresponding to worse air quality and greater health concerns.

When the number is above 100, outdoor air is considered unhealthy for sensitive groups including people with CVD. On days with an AQI > 100, it is okay for people with CVD to be outside, but they can consider taking more breaks and do less intense activities. If they have symptoms such as palpitations, shortness of breath, or unusual fatigue, this may indicate a serious problem and they should contact you.

Some patients with CVD may be sensitive to air pollution when the AQI is between 51 and 100. Ask your patient to use the AQI to assess whether they have more symptoms when the AQI is between 51 and 100. If so, refer them to actions to take for people sensitive to poor air quality.

Of note, the Air Quality Index does not include pollen counts . This means that on some days, the Air Quality Index may be low even though pollen levels in the air are high.

• Remind your patients that indoor air can be as polluted as outdoor air.
• Educate patients that cigarette and e-cigarette smoke, candles and air fresheners are indoor sources of air pollution.
• If possible, bring outdoor air in when cooking indoors.
• Encourage patients to allow clean indoor air inside when the AQI is less than 100 (or <50 for sensitive individuals).
• Discuss air purifiers, also known as air sanitizers, air cleaners, and/or air filters used in HVAC systems . While these devices cannot remove all air pollutants, they can improve indoor air quality for many pollutants when used properly. A list of portable cleaners can be found here .
• Some homes have HVAC systems with replaceable filters. These filters have MERV (Minimum Efficiency Reporting Values) ratings or are designated as HEPA (high efficiency particulate air) filters . To effectively remove indoor air pollution, HEPA filters or filters with MERV of 13 or higher can be used.
• Air filters should be replaced regularly.  Replacement frequency depends on how much air pollution is present but can be done every 60-90 days.
• Do-it-yourself (DIY) air cleaners may be a more affordable and accessible alternative to commercial versions to filter out smoke particles and can be constructed using a box fan and a high-efficiency home air filter.
• Counsel your patients to take all medications as directed unless otherwise guided by you or another clinician.
• Review your patient’s medication list with them, highlighting medications that may reduce their heat tolerance such as diuretics, or medications that may need to be adjusted because of interactions with higher heat. See the Heat and Medications page  for more information.
• Provide guidance on proper medication storage, especially for medications that individuals may carry with them, such as inhalers which can malfunction or burst from high heat. Counsel your patients not to leave medications in a car or other places that can get excessively hot. Remind patients that insulin can be degraded by heat and should be refrigerated.
• Counsel your patients to limit sun exposure if they take a medication, such as a statin, that causes sensitivity to the sun. To avoid sunburn which can promote dehydration, recommend applying sunscreen of SPF 30 or greater, using a sun-protective hat and clothing, and trying to stay indoors during the hottest part of the day.
• Plan for what to do in the event of a power outage for medications requiring refrigeration like insulin, for medication delivery devices like nebulizer machines, and for electrical medical devices, like ventilators and oxygen concentrators.

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• Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
• You will be subject to the destination website's privacy policy when you follow the link.
• CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website.

Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.

Volume 30, Number 5—May 2024

Cme activity - synopsis, crimean-congo hemorrhagic fever virus for clinicians—epidemiology, clinical manifestations, and prevention.

Main Article

Clinical phases of Crimean-Congo hemorrhagic fever*

*ALT, alanine aminotransferase; aPTT, activated partial thromboplastin time; AST, aspartate aminotransferase; CCHFV, Crimean-Congo hemorrhagic fever virus; CK, creatine phosphokinase; DIC, disseminated intravascular coagulation; FDP, fibrinogen degradation products; LDH, lactate dehydrogenase; MOF, multiorgan failure; PT, prothrombin time.

1 Current affiliation: Pfizer Inc., New York, New York, USA. These materials reflect only the personal views of the author and may not reflect the views of her employer.

2 Members of this group are listed at the end of this article.

Exit Notification / Disclaimer Policy

• The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
• Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
• You will be subject to the destination website's privacy policy when you follow the link.
• CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website.