title: Enzyme-linked immunosorbent assay for detection of human antibodies to Salmonella typhi Vi antigen.
abstract: An enzyme-linked immunosorbent assay (ELISA) was developed to detect antibodies to Salmonella typhi Vi antigen in human serum, and the results were compared with those from a previously described hemagglutination assay (HA). The ELISA detected Vi antibodies at a titer of greater than or equal to 20 in 40 (52%) of 77 sera from typhoid fever patients, whereas the HA gave titers of greater than or equal to 20 in 35 (47%). Determination of titers of serum specimens from 170 persons without typhoid fever revealed Vi antibody titers of greater than or equal to 20 in 4 (2.3%) by the ELISA and 3 (1.7%) by the HA. Unlike the sensitized erythrocytes used in the HA, the ELISA reagents have a shelf life of greater than or equal to 1 year. The ELISA may be preferred by some laboratories, especially those already performing other ELISA tests.
mesh_terms: D000907:Antibodies, Bacterial / Q000032:analysis*; D000942:Antigens, Bacterial / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D012485:Salmonella typhi / Q000276:immunology*; D014435:Typhoid Fever / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial