The organism is Salmonella typhi. The organism penetrates into intestinal mucosa and takes few organisms to establish an infection. Ulceration occurs and bacteria enter blood and lymph. They can establish infections in lymph, gallbladder, spleen, and skin. Fever and patient debilitation occur.
Some individuals have minor cases and become carries who are a source of the disease.
There are 3-4 carriers per 100,000 in the US Bacterial dysentery , Shigellosis is common and in the US we have 25 cases per 100,000 in infants. In a rural community of Guatemala 1965-1969, there were 200,000 cases per 100,000 population. Infants averaged two infections per year. There are several Shigella species that attack the intestines and cause ulcerous lesions. Symptoms are bloody and mucous diarrhea.