Real-time polymerase chain reaction and culture in the diagnosis of invasive group B streptococcal disease in XXXX : a retrospective study.

@entity1 @entity2623 @entity1892 @entity3
UNASSIGNED: @entity1892 ( @entity1892 ) is a leading cause of invasive disease in @entity1 . Accurate and rapid diagnosis is crucial to reduce morbidity and mortality. Real-time polymerase chain reaction (PCR) targeting the dltR gene was utilised for the direct detection of @entity1892 DNA in blood and cerebrospinal fluid (CSF) from @entity1 at an Irish maternity hospital. A retrospective review of laboratory and @entity1 records during the period 2011-2013 was performed in order to evaluate PCR and culture for the diagnosis of @entity3 . A total of 3570 blood and 189 CSF samples from 3510 @entity1 had corresponding culture and PCR results. Culture and PCR exhibited concordance in 3526 @entity1892 -negative samples and 13 (25  %) @entity1892 -positive samples (n   =   53). Six (11  %) and 34 (64  %) @entity1892 -positive samples were positive only in culture or PCR, respectively. Culture and PCR identified more @entity1892 -positive @entity1 (n   =   47) than PCR (n   =   43) or culture (n   =   16) alone. Using culture as the reference standard, the sensitivity, specificity, and positive and negative predictive values for PCR on blood samples were 71.4  %, 99.2  %, 25  % and 99.9  %, and for CSF samples, they were 60  %, 97.8  %, 42.9  % and 98.9  %, respectively. The sensitivity and positive predictive values were improved (blood: 84.6  % and 55  %; CSF: 77.8  % and 100  %, respectively) when maternal risk factors and other laboratory test results were considered. The findings in this study recommend the use of direct @entity1892 real-time PCR for the diagnosis of @entity2623 in @entity1 with a clinical suspicion of invasive disease and as a complement to culture, but should be interpreted in the light of other laboratory and clinical findings.
