Chapter 8Advising Travelers with Specific Needs

Advice for Air Crews

Phyllis E. Kozarsky

OVERVIEW

As airlines expand their reach and air crews are asked to travel to more exotic destinations, these travelers need to prepare ahead of time for the exposures they may encounter. To some degree, air crews are similar to all travelers to such destinations, but the differences require some modifications of travel health guidance for several reasons:

Layovers are short, often <24 hours.
Travel is frequent.
Travel to new destinations may be on short notice.
Despite short travel times, air crews may be more adventuresome and thus have more risk than typical package tourists.
Air crews may perceive themselves to be low risk because of their generally healthy status and because their exposure time in-country is short.

Given these factors, it is worth noting some guidelines for this special group. In general, American carriers traveling to destinations in the developing world try to inform their air crews about health issues they may face. However, airlines do not necessarily have available on their staff occupational health or other providers who are experts in travel medicine, and the airlines may not be aware of special risks at their destinations. Air crews and clinicians seeing such travelers should, therefore, encourage airlines to avail themselves of professionals who are knowledgeable in the field and who can help determine recommendations for the various destinations served.

Pilots typically know some of the medications and classes of medications that are not permitted while flying, so clinicians should always discuss medication options. Medications with central nervous system adverse events should not be prescribed, and a trial should be taken between trips of any medication that could have side effects that may interfere with flying. Pilots and flight attendants should also be aware that certain foods and beverages containing trace amounts of products could cause a drug screen to turn positive. They should also consider the effects of drinking too much water (possibly causing hyponatremia) on health and drug tests. If questions arise, an aeromedical examiner should be consulted who will know the Federal Aviation Administration rules for what medications can and cannot be taken by pilots. These physicians are responsible for certifying that pilots are fit to fly, and they examine pilots on a regular basis.

Although any travel health provider can see and advise flight crews, it is important to ask the crew member what the airline may require, in addition to what is required or recommended to maintain the person’s health while traveling. If in doubt, the travel health provider should contact the airline medical director or occupational health department for guidance. For example, some air crews primarily fly domestic routes or routes to Western Europe or Japan, so would not fly to a region of yellow fever risk in their normal daily work. However, an airline may require that crew members without contraindications be vaccinated against yellow fever, so that the airline has flexibility to shift crews and be able to address any urgent need.

GENERAL HEALTH MEASURES

Although pilots are required to have periodic physician visits to ensure they are fit to fly, these may not address some issues that may affect them when they travel internationally, particularly to destinations in the developing world. Flight attendants and others should also consider asking their health care providers about these recommendations:

Administering a periodic tuberculin skin test, if traveling frequently to destinations where the prevalence of tuberculosis is much higher than in the United States, where the incidence of antimicrobial resistance is higher, and where the crew member will be in close contact with crowds (www.who.int/tb/challenges/mdr/en/).
Checking at each visit to make sure that routine immunizations are up-to-date (see below).
Immunizing against seasonal influenza every year when the vaccine becomes available, and immunizing against any outbreak influenza strain, should a special vaccine be available.

In addition, all medications for chronic conditions should be carried in extra quantities, as they may not be available at some locations, and even if available and less costly, may be counterfeit (see Chapter 2, Perspectives: Counterfeit Drugs). The business of manufacturing counterfeit medications in developing countries is huge and growing; it is impossible to tell from the packaging or pills if they are counterfeit. Some counterfeit drugs contain little or no active ingredient, and others contain toxic contaminants.

Vaccinations

Because of the frequency of travel to international destinations, air crews may be exposed to various diseases that are not common in the United States. For example, measles can be a life-threatening illness for adults and is more common in most of the world, including Europe, because of lack of mandatory childhood immunization against the disease in many countries. International flight crews should consider a travel health visit to ensure as complete protection as possible. Some may have short notice before traveling to new destinations; thus, travelers should be asked about this possibility during their visit, so that vaccinations for an upcoming trip—that may not be imminent—may be given, or a series may be started early. Providers should educate travelers about health risks in the various destinations; whether certain vaccinations are administered will depend on the traveler’s tolerance for risk.

Routine Vaccinations

All travelers should make sure they are up to date with routine vaccinations (see the separate sections on these diseases in Chapter 3):

Measles—A person born in the United States before 1957 is assumed to be immune to measles. If born after, it is important to have documentation of having had the disease or having had 2 vaccine doses against measles. Measles vaccine is typically given as MMR (measles-mumps-rubella).
Varicella—Strongly recommended for travelers with no history of chickenpox
Polio—A single booster is recommended as an adult. Although transmission of the polio virus is not a problem in the Western Hemisphere, it remains a risk in some countries in sub-Saharan Africa and in Asia.
Diphtheria-tetanus-pertussis—Administered at 10-year intervals (a single booster of the triple combination, and thereafter Td) for complete protection
Hepatitis B—Administered to all children and adolescents in the United States, it is advisable for frequent travelers because of unpredictability of exposure.
Hepatitis A—Administered to all children in the United States, it is advisable for all travelers.
Others—Any age-related (such as varicella-zoster) or health maintenance-related (such as pneumococcal) vaccinations should be considered.

Special Vaccinations for Travel

Although there are no established guidelines or recommendations for the use of travel vaccinations in pilots and other air crews, it may be reasonable to offer meningococcal, Japanese encephalitis, yellow fever, and typhoid vaccine to this special population because of their frequent, short-stay, and at times unpredictable travel and destinations. As well, they are generally a group who travels frequently beyond work, so they should always be asked during a consultation whether they plan other travel itineraries that can be addressed at the same time.

Malaria Chemoprophylaxis

Crew members are typically informed by their airline as to which destinations harbor malaria. Some European and Asian air carriers have longer experience flying to destinations where malaria is endemic, and these airlines have various policies with respect to its prevention. Although there may be malaria transmission in some areas of destination countries, sometimes there is none in the capitals or the larger urban areas to which the major American carriers fly (such as in China or the Philippines). This is generally not the case in sub-Saharan Africa, where there can be substantial exposure during a short 24-hour layover (however, in Kenya, there is no malaria risk in Nairobi). Although there may be little risk at the hotels in the destination, risk may be increased at the international airports and during unpredictable delays in transit. Even during short single stops (for example, in West Africa en route to South Africa) there is some risk when the aircraft doors are open. Little published data are available on the risk of malaria for flight crews with short layovers, but some information suggests that it is less than that for tourists.

Flight crew members should be educated about the risk of malaria at their destinations and have an individual risk assessment for preventive measures. For destinations where the prevalence of malaria is high (countries in West Africa, for example), crew members should take prophylaxis for layovers. For other destinations where crews are thought to be at low risk based on local intensity of transmission, accommodations, and personal behaviors, they may be advised to use insect repellents and no chemoprophylaxis. Flight crews should always:

Educate themselves as much as possible about malaria.
Understand the importance of personal protective measures such as repellents, and use them properly.
Take chemoprophylaxis if recommended by their doctor.
Know that if fever or chills occur after exposure, it is a medical emergency.
Know how they can get medical assistance at their destinations or at home in the event of symptoms or signs of malaria.

There are several options for malaria chemoprophylaxis, depending on the destination city. The combination of country-specific recommendations that can be accessed either in this text (see Chapter 3, Yellow Fever and Malaria Information, by Country) or on the CDC Travelers’ Health website (www.cdc.gov/travel) should help with this decision, along with the individual assessment. Chemoprophylaxis recommendations for pilots and air crew include the following:

Mefloquine—The current product label for mefloquine contains a caution against using mefloquine for malaria prophylaxis in pilots.
Chloroquine—There are no contraindications for use of chloroquine in pilots or air crew. Chloroquine may not be the preferred option for many because of the need to continue taking the drug for 4 weeks after the last exposure, thus requiring more than 4 weeks of drug administration for even a single night of exposure. In addition, in many areas malaria is resistant to chloroquine.
Atovaquone-proguanil—There are no contraindications for use of atovaquone-proguanil in pilots or air crew members. In addition, because of the short-stay nature of their travel, use of atovaquone-proguanil as chemoprophylaxis may be preferred because of the need to take the drug for only 7 days after leaving an area of exposure risk.
Doxycycline—There are no contraindications for use of doxycycline in pilots or air crew. Doxycycline may not be the preferred option for many because of the need to continue taking the drug for 28 days after the last exposure, thus requiring >4 weeks of drug administration for even a single night of exposure.
Primaquine—There are no contraindications for use of primaquine in pilots or air crew. Like atovaquone-proguanil, use of primaquine as chemoprophylaxis may be attractive because of the need to take the drug for only 7 days after leaving an area of exposure risk. A blood test for the enzyme glucose-6-phosphate dehydrogenase is required before prescribing. CDC recommends primaquine for prevention of malaria in areas with mainly Plasmodium vivax.

Food and Water Precautions and Travelers’ Diarrhea

Pilots and air crew members should follow the same safe food and water precautions and prevention and management of travelers’ diarrhea as other travelers (see Chapter 2, Travelers’ Diarrhea). They should also be well versed in the recognition and self-treatment of travelers’ diarrhea to avoid unnecessary illness that would affect their job performance.

Bloodborne Infections and Sexually Transmitted Diseases

Although these risks and preventions are addressed in more detail in other sections, it is worth reiterating that frequent travelers have an increased likelihood of engaging in casual and unprotected sex. It is common to think that people from Western countries would have the same risk of HIV and STDs; however, travelers have far higher rates of such infections. Dental procedures and activities such as acupuncture, tattooing, and piercing also are ill-advised during travel to developing countries.

BIBLIOGRAPHY

Bagshaw M, Nicolls DS. Aircraft cabin environment. In: Keystone JS, Kozarsky PE, Freedman DO, Nothdurft HD, Connor BA, editors. Travel Medicine. Philadelphia: Mosby; 2008. p. 447–61.
Byrne N. Urban malaria risk in sub-Saharan Africa: where is the evidence? Travel Med Infect Dis. 2007 Mar;5(2):135–7.
Byrne NJ, Behrens RH. Airline crews’ risk for malaria on layovers in urban sub-Saharan Africa: risk assessment and appropriate prevention policy. J Travel Med. 2004 Nov–Dec;11(6):359–63.