Study objectives: Evaluation of a newly available rapid
(15 min) immunochromatographic membrane test (ICT) to detect
Streptococcus pneumoniae in urine samples, in order to
assess its utility in the diagnosis of bacteremic and nonbacteremic
Setting: We studied urine samples from 51
patients with bacteremic and nonbacteremic pneumonia due to S
pneumoniae diagnosed by blood culture and pneumococcal
polysaccharide capsular antigen detection by
counterimmunoelectrophoresis in urine samples, 16 patients with
probable pneumococcal pneumonia, 71 patients with nonpneumococcal
pneumonia, and 16 patients with pneumonia but no pathogen identified.
Urine samples were collected and frozen at − 20°C until used.
The ICT test was performed following the instructions of the
Measurements and results:S
pneumoniae antigen was detected in 41 of 51 patients with
pneumococcal pneumonia (80.4%); results were positive in 23 of 28
bacteremic cases (82.1%) and in 18 of 23 nonbacteremic cases (78.3%).
From patients with a diagnosis of presumptive pneumococcal pneumonia,
antigen was detected in seven urine samples (43.7%) and also in one
case of the 16 patients with pneumonia but no pathogen identified. The
specificity of the ICT test was 97.2%.
The ICT assay is a valuable tool for the diagnosis of pneumococcal
pneumonia, especially for the nonbacteremic cases.