Typhoid fever is caused by which pathogen?

1. syllabus names Salmonella typhi as the causative agent of typhoid. 2. The bacterium enters through contaminated food or water and reaches the small intestine. 3. Confirmed by the Widal test. 4. Symptoms include sustained high fever (39-40°C), weakness, headache and loss of appetite. _Source: syllabus Biology, Ch 7 "Human Health and Disease", §7.1_