Interpretation of sequential testing for syphilis among 540 Ethiopian factory workers who donated a mean of eight consecutive blood samples during 5 years of follow up, before and after retesting for sequential inconsistent RPR/TPPA results
| No of subjects categorised according to their test results before retesting | |||||
|---|---|---|---|---|---|
| Category (a) | Category (b) | Category (c) | |||
| *17 subjects, formerly classified as (c), were interpreted as no syphilis after retesting. | |||||
| †Defined as consistent sequential RPR seroconversion with or without (in case TPPA was positive throughout) TPPA seroconversion. | |||||
| 194 subjects with all consecutive samples RPR−/TPPA− | 170 subjects with at least one sample RPR+/TPPA− | 176 subjects with at least one sample TPPA+ | |||
| Interpretation of test results in subjects after retesting of samples in 93 subjects in (c) | No syphilis (consecutive samples TPPA−) | Past syphilis (consecutive samples RPR−/TPPA+) | Prevalent syphilis (consecutive samples RPR+/TPPA+) | Incident syphilis† | |
| 364+17* subjects (70.5%) | 111 subjects (20.6%) | 37 subjects (6.9%) | 11 subjects (2.0%) | ||