Evaluation of Streptococcus pneumoniae urinary antigen test in healthy children with nasopharyngeal pneumococcal carriage

Abstract

We evaluated the influence of colonization with pneumococci on the results of Streptococcus pneumoniae urinary antigen detection assay by testing 23 healthy children aged 1-3 years in one nursery. Nasopharyngeal swab specimens for culture and urine samples for antigen detection test were obtained. 7 of 12 children who were nasopharyngeal carriers of pneumococci had a positive result of the urine antigen test. 3 of 11 children without pneumococci in the nasopharynx also had a positive result of the urine antigen test, who were diagnosed as having acute pneumonia within one month before this study. Thus we found that 58.3% of the children with pneumococcal carriage and 27.3% of non-carriers had false-positive test results. This test is not likely to be useful for diagnosing the etiology of childhood acute pneumococcal pneumonia.