Table 2.

Comparison of ProGastro SSCS assay to culture/EIA for prospectively tested specimens

Species or gene target and clinical site	Resultsa				Performance (% [95% CI])b
	TP	FP	TN	FN	Sensitivity	Specificity
C. coli/C. jejuni
A	9	8	327	0	100 (63–100)	97.6 (95–99)
B	5	1	382	0	100 (46–100)	99.7 (98–100)
C	6	2	277	0	100 (52–100)	99.3 (97–100)
D	0	2	120	0	NA	98.3 (94–100)
Total	20	13c	1,106	0	100 (80–100)	98.9 (98–99)
Salmonella spp.
A	5	0	339	0	100 (46–100)	100 (99–100)
B	7	4	377	0	100 (56–100)	98.9 (97–100)
C	1	0	284	0	100 (55–100)	100 (98–100)
D	7	6	108	1	87.5 (47–99)	94.7 (88–98)
Total	20	10d	1,108	1e	95.2 (74–100)	99.1 (98–100)
Shigella spp.
A	2	1	341	0	100 (5–100)	99.4 (97–100)
B	13	4	371	0	100 (72–100)	98.9 (97–100)
C	0	0	285	0	NA	100 (98–100)
D	0	1	121	0	NA	99.1 (95–100)
Total	15	6f	1,118	0	100 (75–100)	99.4 (99–100)
stx1 and/or stx2
A	0	2	341	0	NA	92.9 (90–95)
B	4	2	383	0	100 (40–100)	99.5 (98–100)
C	4	3	278	0	100 (40–100)	98.9 (97–100)
D	1	2	119	0	100 (5–100)	98.3 (94–100)
Total	9	9g	1,121	0	100 (63–100)	99.2 (98–100)

^aTP, true positive; FP, false positive, TN, true negative; FN, false negative;

^bCI, confidence interval; NA, not applicable.

^cSix of 13 were positive for C. jejuni or C. coli following bidirectional sequencing analysis.

^dTen of 10 were positive for Salmonella spp. following bidirectional sequencing analysis.

^eOne of 1 was negative for Salmonella spp. following bidirectional sequencing analysis.

^fSix of 6 were positive for Shigella spp. following bidirectional sequencing analysis.

^gEight of 9 were positive for stx₁, stx₂, or both following bidirectional sequencing analysis.