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Table 4 Sensitivities and specificities of multiplex real-time PCR for detection of S. pneumoniae and H. influenzae.

From: Multiplex quantitative PCR for detection of lower respiratory tract infection and meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis

Species Reference test Detection limit of the assay Cutoff 105 copies/mL
   Sensitivity Specificity PPVa NPVb Sensitivity Specificity PPV NPV
S. pneumoniae BAL culture, blood culture and urinary antigen test 95%
(20/21)
75%
(101/135)
37%
(20/54)
99%
(101/102)
90%
(19/21)
80%
(108/135)
41%
(19/46)
98%
(108/110)
  BAL culture, blood culture and urinary antigen tes + lytA PCR 91%
(43/47)
89%
(97/109)
78%
(43/55)
96%
(97/101)
79%
(37/47)
95%
(104/109)
88%
(37/42)
91%
(104/114)
H. influenzae BAL culturec 90%
(28/31)
65%
(81/125)
39%
(28/72)
96%
(81/84)
81%
(25/31)
85%
(106/125)
57%
(25/44)
95%
(106/112)
  BAL culturec + fucK PCRd 93%
(69/74)
96%
(79/82)
96%
(69/72)
94%
(79/84)
63%
(47/74)
100.0%
(82/82)
100%
(47/47)
75%
(82/109)
  1. a Positive predictive value
  2. b Negative predictive value
  3. c Blood culture were also performed for H. influenzae but all were negative
  4. d fucK PCR was performed in the PCR positive and culture negative samples
  5. Analysis of bronchoalveolar lavage from 156 adults with lower respiratory tract infection.