International travelers should be aware that some countries require disinsection of certain passenger aircraft in order to prevent the importation of insects such as mosquitoes. Disinsection procedures may include the spraying of the aircraft passenger compartment with insecticide while passengers are present. While the recommended disinsection procedures have been determined to be safe by the World Health Organization, they may aggravate certain health conditions (i.e., allergies). Travelers with such conditions or who are otherwise interested in determining what disinsection procedures may be performed on a particular flight should contact their travel agent or airline.