Table 4 Distribution of Architect sample/cut-off (S/CO) ratios for 1059 non-treponemal and 147 treponemal sera

S/CO ratio	From routine screening		Previous positive cases from serum bank
S/CO ratio	Non-treponemal	Treponemal	Primary	Secondary	Early latent	Latent—unknown duration
<0.1	715	0	0	0	0	0
0.1–0.19	294	0	0	0	0	0
0.2–0.29	27	0	0	0	0	0
0.3–0.39	6	0	0	0	0	0
0.4–0.49	3	0	2	0	0	0
0.5–0.59	2	0	0	0	0	0
0.6–0.69	0	0	0	0	0	0
0.7–0.79	1	0	0	0	0	0
0.8–0.89	0	0	0	0	0	0
0.9–0.99	1	0	0	0	0	0
1–1.09	0	0	1	0	0	0
1.1–1.19	0	0	2	0	0	0
1.2–1.29	2	0	1	0	0	0
1.3–1.39	0	0	3	0	0	0
1.4–1.49	2	0	0	1	0	0
1.5–1.59	1	0	0	0	0	0
1.6–1.69	0	0	2	0	0	0
1.7–1.79	1	0	1	1	0	0
1.8–1.89	0	0	0	0	0	0
1.9–1.99	1	0	0	0	0	0
2–2.99	1	4	5	2	0	0
3–3.99	1	1	2	0	1	1
4–4.99	1	1	2	0	0	1
5–9.99	0	4	5	2	0	0
10–19.99	0	12	15	19	5	3
20–29.99	0	24	34	4	3	6
30–39.99	0	2	4	0	0	1
Total	1059	48	79	29	9	12