Re-evaluating STI prophylaxis following sexual assault: The role of DoxyPEP

Sexual assault (SA) remains a significant global concern. Recent UK data estimates that from the age of 16 years, one in four women and one in 18 men experience rape or sexual assault. ¹ Despite increased public discourse and advocacy, fewer than one in six individuals report these crimes to law enforcement authorities. ²

Following SA, bacterial STI rates at baseline screening range from 3%–12%, with chlamydia being most commonly reported.^3–6 There is a paucity of data on STI transmission directly linked to SA due to low follow-up rates and difficulty in determining time of acquisition. ⁷ Furthermore, legal considerations may limit testing practices: a positive result might be used to discredit the survivor; STI testing may not be undertaken to preserve forensic evidence. ⁸

The provision of prophylactic antibiotics following SA remains complex and nuanced, with international guidelines differing in their recommendations. The British Association for Sexual Health and HIV (BASHH) sexual violence guidelines advise against routine antibiotic prophylaxis in SA, recommending case-by-case assessment. ⁹ US guidance advises offering empiric treatment (ceftriaxone, doxycycline, metronidazole) to all survivors presenting within 7 days. ¹⁰ The World Health Organization (WHO) does not recommend routine prophylaxis, citing limited evidence. ¹¹ The Working Group on Sexual Violence suggests that presumptive treatment without testing may be justified, as STI testing adds little legal value. ¹² Notably, all current SA guidance pre-dates the advent of the doxycycline post-exposure prophylaxis (doxyPEP).

The efficacy of doxyPEP in preventing chlamydial and syphilis infections has generated discussion within sexual health, but its potential use following sexual assault has been overlooked. Recent BASHH guidelines suggest considering doxyPEP on a case-by-case basis following SA. ¹³ Survivors of sexual violence often experience a loss of autonomy, and offering STI prophylaxis may help restore a sense of agency. Given variable follow-up attendance rates (10–77%)^5,8,14–17 and rising STI diagnoses, doxyPEP may offer partial assurance where disengagement from care is likely and follow-up testing could be facilitated through home testing kits, minimising re-traumatisation and unnecessary physical examinations.

Women are often underserved by sexual health prevention modalities and underrepresented in clinical trials. Event-based HIV pre-exposure prophylaxis (PrEP) was not evaluated in cisgender women (CGW), and the pivotal trial for tenofovir alafenamide-based PrEP excluded this group. ¹⁸ Data for the effectiveness of doxyPEP in this population is limited to one RCT which found no statistically significant reduction in bacterial STIs. ¹⁹ These findings have been attributed to sub-optimal adherence among study participants, with stigma and privacy concerns identified as key barriers for women. ²⁰ Furthermore, observed inter-individual variability in vaginal drug concentrations compared to rectal tissue may have contributed to the reported outcomes. ²¹

Integrating DoxyPEP in SA care respects the survivor’s autonomy while balancing public health priorities and trauma-informed care. STI prophylaxis is generally acceptable to survivors^8,22 but ethical barriers preclude formal evaluation. Therefore, services should consider offering doxyPEP to individuals presenting within 72 hours of SA regardless of gender. Sexual assault remains a disproportionate threat to females, and without further research evaluating doxyPEP in this population, we risk perpetuating a cycle of neglect in STI prevention for women.