Evaluation of Streptococcus pneumoniae-urinary antigen detection kit in patients with community acquired pneumonia

Abstract

We evaluated a new rapid urinary antigen detection kit. NOW Streptococcus pneumoniae (Binax Inc., USA) that detected S. pneumoniae antigen by immunochromatographic membrane assay, with 66 Japanese adult patients of community acquired pneumonia. Twenty-two (33.3%) patients were found to be positive with the kit and S. pneumoniae was isolated from six patients (27.3%) of these 22 patients. S. pneumoniae was not isolated from eight of the 22 patients by blood or sputum culture. Analysis of clinical laboratory data showed that the levels of C-reactive protein (CRP) in the serum were significantly higher in the urine-antigen positive group than those in the urine-antigen negative group. There were no significant difference between the two groups including renal function, urinalysis, clinical symptom, and severity of pneumonia. Our study suggests that more cases of community acquired pneumonia are caused by S. pneumoniae than conventional tests can currently confirm. Since it is not technically complex, does not require equipment, and detects within as quickly as in 15 minutes, the S. pneumoniae urinary antigen kit is useful for rapid diagnosis of community acquired pneumonia in adults.