HBV vaccination, HIV PEP compliance low among young sexual assault victims

Many paediatric sexual assault victims do not receive hepatitis B virus (HBV) postexposure vaccination and have low compliance to HIV postexposure prophylaxis (PEP), reveals a study in Singapore.

“Improving HBV booster vaccination uptake, HIV PEP adherence and follow-up among children and young persons (CYPs) presenting with sexual assault should be prioritized,” the researchers said.

A total of 278 CYPs who made 292 visits due to sexual assault were included in the analysis. Of these, 40 (13.7 percent) were eligible for HIV PEP, but only 29 (82.9 percent) received it. [Ann Acad Med Singap 2025;54:410-418]

Among CYPs tested at baseline, 9 percent were found positive for Chlamydia trachomatis and 34.9 percent for Gardnerella vaginalis. None of them tested positive for Neisseria gonorrhoeae, Trichomonas vaginalis, HIV, HBV, or hepatitis C.

More than half of CYPs (n=167, 67.6 percent) tested were HBV nonimmune, but only 77 (46.1 percent) were vaccinated. Twenty-seven CYPs were eligible for HBV PEP with immunoglobulin, but only 21 (77.7 percent) received it. Furthermore, 37 sexual assault victims received HIV PEP, including eight deemed ineligible. However, only 10 (27 percent) completed the course. 

There were 153 CYPs (57.7 percent) who attended follow-up overall, and none of them seroconverted for HIV or HBV.

“While most eligible CYPs were offered HIV PEP, uptake and adherence were low, as were outpatient follow-up rates (57.5 percent),” said the researchers, noting that these rates were consistent with those seen in current literature. [Pediatr Emerg Care 2005;21:502-506]

“Factors contributing to poor compliance should be examined to optimize care for this vulnerable population,” they added.

HIV PEP

Most CYPs in this study prescribed HIV PEP were deemed eligible, although five were missed, suggesting the need for more awareness of HIV risks among clinicians.

Previous studies recommend PEP within the first 72 hrs following the sexual assault, particularly for those with oral, vaginal, or anal penetration, with known HIV-positive assailants or assailants with high-risk behaviours. However, unclear histories often complicate the clinical application of PEP. [BMC Health Serv Res 2022;22:441; Curr Opin Infect Dis 2007;20:39-46; https://stacks.cdc.gov/view/cdc/38856]

Moreover, the young age of sexual assault victims makes it challenging to describe the degree of penetration (labial vs vaginal), as well as to ascertain condom use and ejaculation. [Clin Infect Dis 2015;61:S85664]

"This is further hampered by a lack of consensus on the administration of HIV PEP in at-risk populations who present beyond the recommended window for PEP initiation,” the researchers said. 

“Given concerns about drug toxicities and adherence, it is thus unsurprising that decisions around PEP are weighted and require careful, shared discussion among the victims, caregivers, and healthcare providers,” they added. 

In the present study, the researchers reviewed medical records of CYPs aged ≤16 years who presented with sexual assault between January 2022 and August 2023. They also reviewed the assault and assailant characteristics, baseline and follow-up screening for sexually transmitted infections, PEP prescription, adherence, and follow-up attendance.

Sexual assault victims in the preceding 72 hrs by HIV-positive or HIV-status unknown assailants with high-risk characteristics were eligible for HIV PEP.

“Our findings build on prior studies examining the clinical characteristics, prescribing practices of PEP, and follow-up among paediatric sexual assault victims,” the researchers said. “Prospective studies using standardized treatment protocols and risk-stratification tools will be crucial in establishing definitive PEP prescribing guidelines.”