Identification of Streptococcus pneumoniae Revisited

The sensitivities and specificities of several different diagnostic assays for Streptococcus pneumoniae were assessed using 99 clinical isolates of S. pneumoniae and 101 viridans streptococci and were as follows: Pneumoslide, 99 and 87%, respectively; Directigen, 100 and 85%, respectively; Phadebact, 100 and 98%, respectively; deoxycholate drop test, 99 and 98%, respectively; deoxycholate tube test, 100 and 99%, respectively; optochin, 99 and 98%, respectively; and Gram Positive Identification Card, 90 and 96%, respectively. Identification of clinical isolates of S. pneumoniae should be confirmed using one or more diagnostic assays with well-documented high (e.g., ≥95%) sensitivities and specificities.