Typhoid (also called typhoid fever) is caused by the bacterium Salmonella typhi, which infects your gut and blood and causes a fever and other symptoms.
Typhoid bacterium easily passes from one person to another through stools (poo) or sometimes urine (wee), for example, if an infected person doesn’t wash their hands properly after going to the toilet.
If someone else eats food or drinks water that's been contaminated with the bacterium, they can develop typhoid.
The incubation period (between when you come into contact with the bacterium and get sick) is usually 7 to 14 days but can be from 3 to 60 days.
Some people can be carriers and infect others without being sick themselves.
There is a milder version of typhoid called paratyphoid fever.