Typhoid fever is caused by a bacteria named salmonella typhi. It is spread by feaco-oral route and it is contagious disease. Typhoid bacteria come out from the body via feacal matter and if your hand hygiene is not proper you can spread infection to others. There is one historic incidence behind typhoid. Typhoid Mary Mary was a cook and suffering from typhoid and due to poor hand hygiene she spread the infection in the community.