Typhoid fever, the art of its laboratory diagnosis

Abstract

The diagnosis of typhoid fever is always complex. There is no pathognomonic symptomatology. Historically, Widal reaction (contained in febrile antigens) was useful for its diagnosis and management. Currently, this practice perpetuates only in underdeveloped countries because it is a quick and cheap test, however, useless. The diagnosis of typhoid fever is accomplished only by two tests: isolating Salmonella typhi or detecting its DNA, by culture or polymerase chain reaction, respectively. Immunofluorescence in feces is a useful test, guiding us to start antimicrobial therapy immediately.