Figure 1From: Estimating age-dependent per-encounter chlamydia trachomatis acquisition risk via a Markov-based state-transition model Data collection scheme for the YWP: the blue dots indicate the determination of the STI status at enrollment and all subsequent quarterly visits; the light green dots indicate antimicrobial treatment of infected subjects at the visits; and the red dots indicate face- to- face interviews in which subjects reveal the number of unprotected coital events. Back to article page