Determination of Pneumococcal Pneumonia Frequency through Isolation of Pneumococcal Antigen from Urine Using Immunochromatographic Method (Binax NOW)

Streptococcal pneumoneae is the most common etiologic agent of community-acquired pneumonia. Pneumococcal isolation from sputum can only demonstrate the possibility of pnumococcal infection because of the possibility of carrying. Definitive diagnosis is made by isolation of pnumococcus from blood and sterile body fluids. Real percentage of positive blood culture in pnumococcal pneumonia is around 15-30%. If urine pneumococcal antigen detection is added to conventional laboratory methods, pnumococcal diagnosis can be increased by 38.9%. The aim of this survey was determining the prevalence of pnumococcal pneumonia in bacterial pneumonia through isolation of pneumococcal antigen from urine. Patients and This descriptive cross-sectional study was performed on patients diagnosed with acute bacterial pneumonia. The subjects were above the age of 18 and admitted to Rasoul-e-Akram Hospital in 2007. Urine samples of patients were tested for antigen detection by immunochromatographic method with Binax NOW Streptococcus pneumoneae test. Blood samples of all patients were cultured. Patients who were admitted for elective surgery and had no infection entered the study as a control group. Quantitative variables were evaluated by using mean and standard deviation and qualitative variables were evaluated by using percentage. From the total of 43 patients, 26(60.5%) were men and 17(39.5%) were female. The mean age of the patients was 55.47 (± 22.46) years. S.pneumoneae was isolated from 2 (4.65%) patients by culture(blood and pleural culture) and from five (11.6%) patients by urine antigen test. S.pneumoneae was seen only in spring and winter. Normal leukocyte count was seen in 2 cases and lukocytosis existed in 3 of them. Lobar infiltration was seen in 4 subjects and pleural effusion in 1. In 2 cases of positive pneumococcal culture, urine pneumococcal antigen test was positive. None of the members of the control group had positive urine pneumococcal antigen test. Pneumococcal antigen was isolated from the urine of 5 patients. There was no positive urine pneumococcal antigen test in the control group,which reveals pneumococcal carriage in adults is very low in this study. This study shows urine pneumococcal antigen test is a good diagnostic tool in adults and can help establish diagnosis.