Evaluation of rapid screening assay for the direct detection of Haemophilus influenzae type b antigen in cerebrospinal fluid in paediatric meningitis

ABSTRACT

OBJECTIVE: To evaluate the use of a rapid antigen detection assay for detection of Haemophilus influenzae type b (Hib) antigen in cerebrospinal fluid (CSF) from children with meningitis. DESIGN AND METHODS: CSF specimens from children with meningitis were tested for bacterial antigens using latex agglutination (LA) tests and a novel rapid antigen test after all other investigations were completed. The analytical sensitivity of the antigen assays was compared using sterile CSF to which Hib was added. RESULTS: Hib meningitis was confirmed by culture in 4/10 (3.3 percent) of paediatric patients and in none of 29 neonates. The sensitivity and specificity of both LA and the rapid antigen test were 100 percent and 98.6 percent, respectively. The rapid screening assay also gave a positive result in a case of meningococcal meningitis. In CSF spiked with Hib, LA detected 4.2 x 10 5 cfu, while the rapid assay detected 100 cfu. CONCLUSIONS: Both LA and the rapid antigen assay detected all cases of Hib meningitis, but the analytical sensitivity of the rapid screening assay was much greater. Prospective studies of the rapid test for detection of other bacterial pathogens are required.(Au)