A single blood culture is positive in only half the cases. Stool culture is not usually positive during the acute phase of the disease. Bone marrow culture increases the diagnostic yield to about 80% of cases. The Widal test is an old serologic assay for detecting IgM and IgG to the O and H antigens of salmonella. The test is unreliable but is widely used in developing countries because of its low cost. Newer serologic assays are somewhat more sensitive and specific than the Widal test but are infrequently available. Because there is no definitive serologic test for typhoid or<unk>  fever, the diagnosis often has to be made clinically.<unk>  B is diagnosed by the isolation of the agent in blood or stool and demonstration of antibodies anti BH in the Widal test. Antibodies to<unk>  C are not usually tested and the diagnosis is made with blood cultures.
Paratyphoid fever laboratory findings
Trench fever laboratory findings
Typhoid fever laboratory findings
Relapsing fever laboratory findings
Rift valley fever laboratory findings
Scrub typhus laboratory findings
Rocky Mountain spotted fever laboratory findings
Lassa fever laboratory findings