CATIE statement on the use of doxyPEP to prevent syphilis

Syphilis rates in Canada are on the rise. This includes a long-standing outbreak among gay, bisexual and other men who have sex with men (gbMSM) and a more recent, rapidly worsening heterosexual outbreak. A steep increase in new syphilis cases among cis women has led to the re-emergence of congenital syphilis (syphilis passed to infants during pregnancy).

The health effects of untreated syphilis can be serious, including neurological disease and disability. Untreated syphilis in a pregnant person often causes miscarriage or stillbirth or results in children being born with syphilis.

The rapid rise in syphilis rates means that new prevention tools are urgently needed. One approach is doxycycline prophylaxis. This involves taking the antibiotic doxycycline to prevent syphilis, either after an episode of condomless sex (doxyPEP) or on a regular, usually daily, basis (doxyPrEP). Of note, doxycycline cannot be used in pregnancy because it can harm the developing fetus.

Research is ongoing to assess the effectiveness of doxyPrEP in preventing bacterial STIs including syphilis.

However, studies have already established that doxyPEP is effective at preventing syphilis among gbMSM and trans women at risk of bacterial STIs. As a result, calls have been made to implement doxyPEP to address the syphilis crisis in these populations.

CATIE released a statement aiming to support community-based service providers and health system decision-makers, by providing evidence-informed recommendations on the rollout of doxyPEP in Canada.

Access the full statement here.