Marriott International is the world's largest hotel company, with brands such as Marriott, Ritz-Carlton, Bulgari Hotels & Resorts, Luxury Collection, St. Regis, W, Westin and Sheraton. Image credit: Marriott Hotel chain Marriott International has introduced a global cleanliness council to promote higher standards of cleanliness as the COVID-19 coronavirus outbreak ravages the travel and tourism business.