Typhoid is caused by Salmonella typhi bacteria, paratyphoid by Salmonella paratyphi. Typhoid and paratyphoid germs are contracted in the stool and urine of infected people. People get the disease from food or water contaminated with infected stool/urine or from water contaminated by sewage containing the bacteria. Once the bacteria enter your body they multiply and spread from the intestines into the bloodstream. Seek treatment early if you have symptoms as this can save your life.
Attribution: Avallain