Rapid detection of pneumococcal antigen in serum samples for diagnosing pneumococcal pneumonia.
OBJECTIVE
The aim of the study is to assess the usefulness of C polysaccharide and polysaccharide capsular antigen detection by immunochromatography (ICT) and enzyme immunoassay (EIA), respectively, in serum samples for diagnosing pneumococcal pneumonia.


METHODS
Adult patients included in the study were classified in the following groups: In group 1 we studied 101 serum samples from patients with pneumonia due to Streptococcus pneumoniae. In 53 cases the pneumonia was bacteremic. The second group contained 113 serum samples from patients with no pneumococcal pneumonia. Group 3 was made up of 40 serum samples from healthy subjects with no clinical or radiological signs of pneumonia.


RESULTS
Using ICT, antigen was detected in 50% of patients with pneumococcal pneumonia, in 64.3 and 40.9% of patients with bacteremic and non-bacteremic pneumococcal pneumonia, respectively. Using EIA, antigens were detected in 35.8% of patients with pneumococcal pneumonia, in 45 and 22.2% of patients with bacteremic and non-bacteremic pneumococcal pneumonia, respectively.


CONCLUSIONS
In conclusion, the sensitivity of the tests is low. However, in special situations, where obtaining large volume of urine is difficult, they could be a complementary method in the rapid diagnosis of pneumococcal pneumonia.
Domínguez
J
J
Servei de Microbiologia, Hospital Universitari Germans Trias i Pujol, Badalona, Facultat de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain. jadoming@ns.hugtip.scs.es
Andreo
F
F
Blanco
S
S
Ruiz-Manzano
J
J
Prat
C
C
Latorre
I
I
Galí
N
N
Rivelo
R
R
Matas
L
L
Ausina
V
V
D000328:Adult; D000942:Antigens, Bacterial / Q000097:blood*; D016667:Bacterial Capsules / Q000097:blood*; D002845:Chromatography / Q000379:methods; D006801:Humans; D007124:Immunoenzyme Techniques; D011018:Pneumonia, Pneumococcal / Q000175:diagnosis* / Q000382:microbiology; D011135:Polysaccharides, Bacterial / Q000097:blood*; D012680:Sensitivity and Specificity; D013296:Streptococcus pneumoniae / Q000276:immunology*; D013997:Time Factors
D000942:Antigens, Bacterial; D011135:Polysaccharides, Bacterial; C027158:polysaccharide C-substance (Streptococcus)