Table 1. Summary of the clinical and laboratory characteristics of study subjects included in this study.

Patient Number	HIV status	Syphilis stage	Sample type	Pre or post- treatment sampling #	PCR Whole Blood	PCR Serum	RPR titre	TPPA titre
1	Positive	Secondary	Plasma	Pre	Positive	Indet.	1/512	>1/20480
2	Negative	Primary	Plasma	Pre	Negative	Indet.	1/4	1/160
3	Positive	Early latent	Plasma	Pre	Negative	Positive	1/1	1/1280
4	Positive	Secondary	Plasma	Pre	Positive	Positive	1/128	1/20480
5	Positive	Secondary	Plasma	Pre	Positive	Positive	1/128	>1/20480
6	Negative	Secondary	Plasma	Pre	Negative	Positive	1/128	>1/20480
7	Positive	Early Latent	Plasma	Pre	Positive	Positive	1/64	1/10240
8	Positive	Secondary	Plasma	Pre	Positive	Indet.	1/32	1/1280
9	Positive	Secondary	Plasma	Pre	Positive	Positive	1/512	>1/20480
			Urine
10	Negative	Primary	Plasma	Pre	Positive	Indet.	1/16	1/5120
			Urine
11	Positive	Secondary	Plasma	Pre	ND	Indet.	1/128	>1/20480
			Urine
12	Negative	Secondary	Plasma	Pre	Positive	Negative	1/32	>1/20480
13	Positive	Secondary	Plasma	Post	ND	Indet.	1/128	>1/20480
14	Negative	Primary	Plasma	Post	Positive	Indet.	1/16	1/5120
			Urine
15	Negative	Primary	Plasma	Post	Negative	Indet.	1/8	1/1280
16	Positive	Secondary	Plasma	Post	Positive	Negative	1/64	1/20480
17	Positive	Primary	Plasma	Post	Positive	Negative	1/64	>1/20480
18	Positive	Secondary	Plasma	Post	Negative	Negative	1/128	>1/20480

Legend: ^#- patients were treated with intramuscular injection with 2.4 MU Benzathine penicillin G; Indet.- indeterminate PCR result, second confirmatory PCR was not performed; ND- not done