Travel can facilitate the transfer of communicable disease. The volume and rapidity of travel
can have an international impact on disease. This is particularly true for aircraft, as the global
span of the aviation industry requires the loading and rapid transport of people and supplies
from many locations all over the world. With the 21st-century potential for millions of people
to have access to air travel on a global scale come the added problems encountered by aircraft
operators that transit both into and out of disease-affected areas or areas with variable and
sometimes inadequate standards of general hygiene and sanitation.