The present study was designed to evaluate the applicability of th.: use of the rapid test, NOW
test, to middle ear effusions and to study its validity characters as a diagnostic test for streptococcus
pneumoniae infection of the middle ear with effusion. The study included 40 children with chronic otitis
media with effusion (OME) and scheduled for myringotomy. There were 10 patients with bilateral and
30 with unilateral OME. The middle ear effusions were collected at the time of myringotomy and were
cultured and also processed for the NOW test. Twenty-nine (58%) specimens gave sterile culture, while
the other twenty-one (42%) specimens gave bacterial growth. Streptococcus pneumoniae grew on 7
cultures. NOW test gave 9 positive results, 6 gave bacterial growth on culturing of the specimen while
the other three specimens gave sterile culture. NOW test could diagnose the presence of streptococcus
pneumoniae infection with sensitivity 85.7%, specificity 93%, and accuracy 92% and with a negative
predictive value (1010 of 97.6%. NOW test could detect antibodies in three specimens of those
diagnosed by culture as being sterile. Thus, NOW test could detect antibodies against streptococcus
pneumoniae wall antigen with a sensitivity of 90%, specificity of .100%, and accuracy of the diagnosis
being 98% and PPV of 100% and NPV of 97.6%. We can conclude that NOW test proved to be simple,
rapid and reliable test for diagnosis of streptococcus pneumoniae infection and also could detect
carriers of infection with a negative predictive value of 97.6%. |
