Evaluation of a commercial latex particle agglutination test for rapid diagnosis of Haemophilus influenzae type b infection.

The effectiveness of a commercially available latex particle agglutination test (Bactogen) in the diagnosis of invasive Haemophilus influenzae type b infection was evaluated. Bactogen correctly diagnosed all 27 patients with bacteriologically proven H influenzae type b infection (sensitivity 100%). Two of 39 patients with proven, non-H influenzae type b infections had false-positive tests (specificity 95%). One of 103 sera and 0 of 55 urine specimens from hospitalized adults contained detectable H influenzae type b antigen. Bactogen is a sensitive, specific, commercially available test for rapid diagnosis of H influenzae type b infection.