ANTIGEN-DETECTION IN OROPHARYNGEAL SECRETIONS FOR RAPID DIAGNOSIS OF PNEUMOCOCCAL PNEUMONIA

To determine the value of detection of antigen in the oropharynx in th e diagnosis of pneumococcal pneumonia, oropharyngeal secretions were c ultured for the presence of Streptococcus pneumoniae and tested for th e presence of pneumococcal antigen. Sputum (if available) collected on the same day was also investigated for the presence of antigen. Detec tion of pneumococcal antigen was found to be directly related to the s everity of pneumococcal carriership or infection (p < 0.0001) and was not related to culture results. Patients with pneumococcal pneumonia h ad the highest antigen detection rate (38 %), followed by patients wit h pneumonia of unknown etiology (32 %) and patients with an acute lowe r respiratory tract infection due to Streptococcus pneumoniae (20 %). Pneumococcal carriers had a detection rate of only 9 %. Antigen could be detected in only one patient of the control groups. Although antige n detection in sputum was superior to that in oropharyngeal secretions , concordant results were obtained in 8 (40 %) and 6 (36 %) patients w ith pneumococcal pneumonia and pneumonia of unknown etiology respectiv ely. The results strongly suggest that pneumococcal carriage seldom le ads to a detectable level of antigen, and that antigen detection in th e oropharynx appears to be of additive value in the diagnosis of pneum ococcal pneumonia.