Table 1.

The novel Clostridium difficile diagnostic assay loop-mediated isothermal amplification (LAMP; Illumigene) compared to cell culture cytotoxin B (CTBA) and/or toxigenic culture (TC) as the gold standarda

Diagnostic assayDiagnostic assay compared to CTBA plus TC
SensitivitySpecificityPPVNPV
% (no. of specimens/total no.)CI (%)% (no. of specimens/total no.)CI (%)% (no. of specimens/total no.)CI (%)% (no. of specimens/total no.)CI (%)
LAMP98 (49/50)89–10098 (218/222)95–9992 (49/53)82–9899 (218/219)97–100
CTBA72 (36/50)57–84100 (222/222)98–100100 (36/36)90–10094 (222/236)90–97
TC100 (50/50)93–100100 (222/222)98–100100 (50/50)93–100100 (222/222)98–100
  • a One of the four specimens that tested positive by LAMP only was positive in an in-house rpoA PCR, indicating that both the sensitivity and specificity of the LAMP test are higher. PPV, positive predictive value; NPV, negative predictive value; CI, confidence interval.