Time Sequence in early syphilis:
(1) time after exposure that chancre appears: average 3 weeks
(2) time for seroconversion in nontreponemal tests:
(2a) begins about 2 weeks after appearance of chancre
(2b) 90% seroconvert by 6 weeks after appearance of chancre
(2c) 100% seroconvert by 9-12 weeks after appearance of chancre
(3) time after exposure for development of secondary syphilis: 6-20 weeks
Algorithm
Is a lesion consistent with early syphilis present? (Y or N)
If a lesion is present, is a darkfield or DFA examination positive for spirochetes?
(1) If spirochetes are seen, then treat for syphilis.
If a lesion is not present, or if the direct examination in negative, is a nontreponemal serology test positive?
(1) if positive, then titer the specimen with the nontreponemal test and perform a treponemal serology test.
(2) if negative, repeat testing later. After 6 months from exposure, if a person has not seroconverted, then further testing probably is not warranted.
If the treponemal serology test is
(1) nonreactive, then consider a false positive.
(2) reactive, then treat for syphilis.
