Clinical studies of a new latex particle agglutination test for detection of Haemophilus influenzae type b polyribose phosphate antigen in serum, cerebrospinal fluid, and urine.

A new latex particle agglutination test for direct detection of Haemophilus influenzae type b polyribose phosphate antigen in serum, cerebrospinal fluid, or urine was evaluated from studies at four clinical centers. Although use of a serum buffer significantly reduced inconclusive agglutination of the latex particles, the retesting of serum samples, after heat inactivation and dilution, resolved all serum samples, with one exception, as reactive or nonreactive for the presence of the polyribose phosphate antigen. A clinical accuracy of 100% was obtained for the latex particle agglutination method in respect to its capability for detection of polyribose phosphate antigen in all patients with confirmed infection by H. influenzae type b.