Rapid diagnosis of genitourinary infections by use of the Limulus lysate amebocyte test

The Limulus amebocyte lysate (LAL) assay has realized numerous clinical applications, including rapid diagnosis of significant Gram negative bacteriuria and gonorrhea. Several published studies have demonstrated that the LAL test detects significant Gram negative bacteriuria with greater than 90% accuracy and that the predictive value of a negative test (97%) is similar to that of other currently available screening methods for bacteriuria. The test has also succeeded when used for presumptive diagnosis of gonorrhea in men, although it has not been shown to be superior to Gram stain examination of urethral exudate. The LAL test appears to offer excellent sensitivity for examination of cervical secretions from women being screened for gonorrhea, although the specificity of the test appears low, especially when a low-risk population is being examined.