Typhoid Fever has a long history of human infection, causing the death of many people. While the incidence has decreased with improved hygiene it still is a cause of serious infection, especially in developing countries.
Causative Salmonella species: S. enterica serovar Typhi
Exposure: contaminated food or water
Incubation period: usually 5-14 days
Duration of symptoms: 2-4 weeks
Clinical features:
(1) fever
(2) headache
(3) apathy to delirium
(4) gastroenteritis
(5) bacteremia with dissemination to bone marrow, spleen, liver, aorta, bone, and other sites
Complications may include:
(1) aortitis
(2) intestinal perforation
(3) GI hemorrhage
(4) encephalopathy or meningitis
(5) pneumonia
(6) DIC
(7) focal abscess
(8) chronic carriage
Infections tend to be more severe in immunocompromised patients.
Paratyphoid fever is similar but clinically less severe. It is due to S. enterica serovars Paratyphi A, Paratyphi B and Paratyphi C.
