Impact of the Daily Doxycycline Pre-exposure Prophylaxis (PrEP) on the Incidence of Syphilis, Gonorrhoea and Chlamydia

1\. This study is a non-randomized observational cohort trial using before and after comparison to evaluate intervention 2. It would mimic the conditions that would occur outside a clinical trial. 2. After consent and enrolment, all procedures will be guided by the Australian STI Management Guidelines. 3\. All enrolling participants will be offered daily doxycycline 100mg 4. All participants will be invited to complete a survey in every 3 months time for 12 months dated from participation. 5\. All follow-up information will be collected through electronic data capture to allow accurate and timely analyses. 6\. Data collection will be from (i) medical records (ii) online self-completed questionnaire