Advice for Aircrews
As airlines expand their reach and aircrews are asked to travel to more exotic destinations, often with short layovers, these frequent travelers need to prepare ahead of time for the exposures they may encounter. To some degree, aircrews 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 24–48 hours.
- Travel is frequent.
- Travel to new destinations may be on short notice.
- Despite short travel times, aircrews may be more adventuresome and thus have more risk than typical tourists.
- Aircrews may perceive themselves to be low-risk because of their generally healthy status and because their in-country exposure time is short.
Given these factors, it is worth noting some guidelines for this special group. In general, air carriers that fly to the developing world try to inform their crews about health issues they may face. However, airlines do not necessarily employ occupational health providers or experts in travel medicine; they may be unaware of special risks at the destinations they serve. Therefore, airlines may wish to avail themselves of professionals who are knowledgeable in the field and who can help make recommendations for their traveling employees.
Pilots are often aware of some of the medications and classes of medications that may interfere with their flight capacity. Providers should not prescribe for pilots medications that affect the central nervous system when flying. Pilots who take sedating antihistamines (including diphenhydramine [Benadryl] and chlorpheniramine) should not fly until more than 5 half-lives have elapsed since the last dose. For diphenhydramine, this equates to a 2-day “no fly” rule (9 days for chlorpheniramine). Trials of new medications or any drugs with potential side effects that could interfere with a pilot’s abilities or judgment should take place between (not during) trips. Prescriptions or recommendations for nonsedating antihistamines (loratadine, desloratadine, and fexofenadine, for example) can be provided after an initial trial period demonstrates they can be taken without adverse effect.
Federal Aviation Authority (FAA)-certified aeromedical examiners (AMEs) examine pilots regularly and are responsible for certifying that they are fit to fly. For some common medications, AMEs might not certify pilots taking them without clearance from the FAA. For other medications, AMEs will advise pilots not to fly. The FAA provides a list of these medications at www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/ame/guide/pharm/dni_dnf. Sometimes medication decisions are made on a case-by-case basis. If questions arise, an AME should be consulted (www.faa.gov/pilots/amelocator).
Although any travel health provider can see and advise flight crews, it is important to ask each crewmember what the company requires, in addition to what is required or recommended to maintain 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 aircrews 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 crewmembers without contraindications be vaccinated against yellow fever, so that the airline has flexibility to shift crews and address any urgent needs.
General Health Measures
Although pilots are required to have periodic provider visits to ensure they are fit to fly, these do not address 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, or where the crewmember will be in close contact with crowds (www.who.int/tb/areas-ofwork/drug-resistant-tb/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.
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 or of poor quality (see Chapter 6, Perspectives : Avoiding Poorly Regulated Medicines and Medical Products during Travel). The manufacture of counterfeit medications in developing countries is a large and growing industry. 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.
Because of their frequency of travel, aircrews 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; it is more common in most of the world, including Europe, because of a lack of mandatory childhood immunization in some countries. In addition, flight crews may not have had varicella as children and, because of their age, may not have been immunized. This illness often occurs at a later age in the tropics; thus, if there is interaction with local populations in these destinations, risk for infection will be higher.
International flight crews should consider a travel health visit to ensure as complete protection as possible. Since some may have short notice before traveling to new destinations, ask aircrew members about this possibility during their visit so that vaccinations for upcoming trips may be given, or a series can be started early. Educate travelers about health risks in the various destinations; administration of certain vaccinations will depend on the traveler’s tolerance for risk.
At a minimum, aircrew members should be up-to-date with routine vaccinations. These vaccines include measles-mumps-rubella (MMR), diphtheria-tetanus-pertussis, varicella, polio, and the seasonal influenza vaccine (see the separate sections on these diseases in Chapter 4).
Although there are no established guidelines or recommendations for the use of travel vaccinations in pilots and other aircrew members, for some it may be reasonable to offer meningococcal, Japanese encephalitis, yellow fever, and typhoid vaccines because of their frequent, short-stay, and at times unpredictable assignments. In addition, because some pilots do relief work or fly to areas of natural disasters, cholera vaccine may also be considered for them. Hepatitis A is advisable for all travelers and may be stressed for aircrews, since most adults in the United States have not been immunized. Hepatitis B is advisable for frequent travelers because of the unpredictability of exposure. Aircrews are generally a group who travel frequently beyond work, so they should always be asked during a consultation whether they are planning other travel that can be addressed at the same time.
Airlines typically inform crewmembers 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 prevention of the disease. While 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 (although in Ethiopia, there is no malaria risk in Addis Ababa).
Although the risk of malaria transmission in hotels at the destination may be low, it may be increased at the international airports, during unpredictable delays in transit, and during outings on layovers. Even during short single stops (for example, in West Africa on the way 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.
Unfortunately, experience has shown that American and European aircrews going to malaria-endemic destinations continue to acquire malaria, as well as develop severe and complicated disease. Some illness may result from lack of awareness of airline recommendations, failure to take precautions against mosquito bites, lack of compliance with antimalarial prophylaxis, or inaccurate information regarding toxicity of medication. Transmission can be focal and intermittent, so prophylaxis for every trip to a highly endemic region should be stressed.
Flight crewmembers should have easy access to educational materials and prophylaxis and, if desired, should be able to have an individual risk assessment for preventive measures. For destinations where the prevalence of malaria is high (countries in West Africa, for example), crewmembers should take prophylaxis for layovers. For destinations where crews are thought to be at low risk based on local intensity of transmission, accommodations, and personal behaviors, providers may advise them to use insect repellents and to take other precautions to avoid mosquito bites (see Chapter 3, Mosquitoes, Ticks & Other Arthropods) but take no prophylaxis. 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 prophylaxis if recommended.
- 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 prophylaxis, depending on the destination city, although needed duration of prophylaxis and adverse effects profiles of some of the drugs make them less than desirable for aircrews. Country-specific recommendations can be accessed either in this text (see Chapter 2, Yellow Fever Vaccine & Malaria Prophylaxis Information, by Country) or on the CDC Travelers’ Health website (www.cdc.gov/travel). International airlines generally prefer the combination drug atovaquone-proguanil; its adverse effect profile and its dosing make it the most suitable for aircrews.
Additional information on malaria prevention may be found in Chapter 4, Malaria.
Other Vectorborne Diseases
In the last decade, several mosquitoborne viruses have emerged or reemerged, including dengue, chikungunya, and Zika (see the individual disease sections in Chapter 4). Preventing mosquito bites in tropical and subtropical destinations is critical to preventing disease. Because Zika virus infection during pregnancy can cause severe birth defects, airlines should develop flight destination policies for pilots and flight attendants who are pregnant, plan to become pregnant, or have a partner who is or may become pregnant.
Food and Water Precautions and Travelers’ Diarrhea
Advise pilots and aircrew members to 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 moderate to severe travelers’ diarrhea to shorten the duration of illness that could affect their job performance. In addition, pilots should make sure that their preferred medication for self-treatment is compatible with flying.
Bloodborne and Sexually Transmitted Infections
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, and travelers have higher rates of HIV and other sexually transmitted infections (see Chapter 9, Sex & Travel). The risk of acquisition may be higher not only for diseases such as gonorrhea and chlamydia but also for chronic illnesses such as hepatitis B and C. Dental procedures and activities such as acupuncture, tattooing, and piercing also are ill-advised during travel to developing countries.
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Phyllis E. Kozarsky