Assessment of enzyme immunoassay versus radioimmunoassay for detection of Legionella pneumophila serogroup 1 antigen in frozen urine specimens.
An enzyme immunoassay (EIA) was compared with a radioimmunoassay (RIA) for detection of Legionella pneumophila serogroup 1 antigen in 37 frozen urine samples. Among 18 samples positive by the RIA at the time of collection, 50% (9 of 18) of stored specimens retained positivity when retested by the RIA whereas 78% (14 of 18) of stored specimens retained positivity when retested by the EIA (P < 0.02). A false-negative result occurred after storage for 5 months or less if the original RIA result showed weak positivity.
Chang
F Y
FY
Special Pathogens Laboratory, Veterans Affairs Medical Center, Pittsburgh, Pennsylvania, USA.
Stout
J E
JE
Yu
V L
VL
D006801:Humans; D007124:Immunoenzyme Techniques; D016952:Legionella pneumophila / Q000302:isolation & purification*; D011863:Radioimmunoassay; D014556:Urine / Q000382:microbiology*