[Diagnostic importance of various methods of determining infectious O-antigenemia in patients with typhoid and paratyphoid fevers A and B].

Altogether 181 patients with typhoid and paratyphoid fever (54 with typhoid fever, 50 with paratyphoid fever type A, and 77 with paratyphoid fever type B) were investigated. Of them 108 (59.7%) patients were examined during the 1st week of disease. Serum specific O-antigens of typhoid and paratyphoid fever agents were determined by enzyme immunoassay (EIA), radioimmunoassay (RIA), and O-aggregate hemagglutination reaction (O-AHA), serum specific O-antibodies were determined by RDHA, EIA, RIA or O-AHA used during the 1st week of disease were twice as effective as RDHA. Combined use of EIA and O-AHA for the detection of serum specific O-antigens made it possible to diagnose typhoid fever in 90.91%, paratyphoid fever type A in 96.15%, and paratyphoid fever type B in 95.55% of cases.