Evaluation of the Sofia Streptococcus pneumoniae FIA test for the detection of S. pneumoniae antigen in urine.

In this study, we evaluated the Sofia Streptococcus pneumoniae FIA test (Quidel Corporation, San Diego, CA, USA), a new immunofluorescence-based lateral flow test for the qualitative detection of S. pneumoniae antigen in urine or cerebrospinal fluid specimens. The analyses of 100 non-concentrated urine samples (including 50 samples from S. pneumoniae cases) showed a sensitivity and specificity (95 % CI) of, respectively, 66.0 % (52.2-77.6) and 100.0 % (92.9-100.0) for the Sofia test, and 62.0 % (48.2-74.1) and 98.0 % (89.5-99.7) for the BinaxNOW SPN Antigen Card. There were no significant differences in sensitivity and specificity between the tests (McNemar's tests, P=0.625 and P=1.000). In conclusion, this study indicates that the Streptococcus pneumoniae FIA test shows similar sensitivity and specificity rates compared to the BinaxNOW SPN Antigen Card.