What testing and follow-up care is recommended for a female patient, taking an oral contraceptive pill, who presents 1 week after a suspected drink/needle spiking and possible sexual assault incident, with no current symptoms of STI or systemic illness, and is approximately 3 days from expected menses?

Post-Sexual Assault Testing and Follow-Up Protocol

Your current testing plan is appropriate for baseline screening, but you must arrange prophylactic antimicrobial treatment immediately and schedule mandatory repeat testing at specific intervals—particularly at 2 weeks for bacterial STIs and at 6 weeks, 3 months, and 6 months for HIV and syphilis. 1

Immediate Management (Current Visit - 1 Week Post-Assault)

Baseline Testing Already Ordered

Your ordered tests are appropriate and include: 1

• HIV serology - baseline only; cannot rule out infection at this timepoint
• Syphilis serology - baseline only; repeat testing mandatory
• Hepatitis B and C serology - appropriate baseline
• Chlamydia & Gonorrhea NAAT (vaginal) - appropriate
• Urine drug screen - appropriate given suspected spiking

Critical Gap: Prophylactic Treatment Should Be Offered Now

Most experts recommend routine prophylactic antimicrobial therapy after sexual assault because follow-up compliance is often difficult and patients benefit from reassurance of treatment. 1 The standard prophylactic regimen is: 1

• Ceftriaxone 125 mg IM (single dose) - covers gonorrhea
• Metronidazole 2 g orally (single dose) - covers trichomonas and bacterial vaginosis
• Azithromycin 1 g orally (single dose) OR Doxycycline 100 mg orally twice daily for 7 days - covers chlamydia

Hepatitis B vaccination should be initiated immediately if the patient is not already vaccinated or immune based on serology. 1 Complete the 3-dose series at 0,1-2 months, and 4-6 months. 1

Additional Testing Consideration

Trichomonas testing via vaginal NAAT should be added if not already included in your chlamydia/gonorrhea NAAT panel. 2 Trichomonas is one of the most frequently diagnosed infections among women following sexual assault. 1

Mandatory Follow-Up Testing Schedule

2-Week Follow-Up

Repeat testing for chlamydia, gonorrhea, and trichomonas at 2 weeks is essential if prophylactic treatment was not given, because infectious agents may not have produced sufficient concentrations to be detected at the initial examination. 1, 2, 3 If prophylactic treatment was provided, this visit can focus on clinical assessment and ensuring treatment completion.

6-Week Follow-Up

Repeat HIV and syphilis serology at 6 weeks after the assault. 1 The window period for these infections means initial negative results do not exclude infection.

3-Month Follow-Up

Repeat HIV and syphilis serology at 3 months (12 weeks) after the assault if initial and 6-week results were negative. 1 This is critical because:

• HIV antibody seroconversion may not be detectable until 3 months post-exposure 2
• Syphilis serologic tests require 6-12 weeks to become positive after infection 1, 3

6-Month Follow-Up

Final HIV testing at 6 months (24 weeks) provides definitive exclusion of HIV acquisition from the assault. 1 Some guidelines recommend this extended timepoint for complete reassurance, though most seroconversions are detected by 3 months.

Pregnancy Considerations

Since the patient is 3 days from expected menses and taking oral contraceptives, perform a urine pregnancy test now as baseline. 1 If her period is late, repeat pregnancy testing at 2 weeks. 1 While oral contraceptives provide pregnancy protection, emergency contraception would have been most effective within 72-120 hours post-assault (this window has now passed). 1

Critical Counseling Points

Window Period Education

Emphasize that negative baseline tests do NOT rule out infection. 2, 3 The patient must understand:

• Bacterial STIs (chlamydia, gonorrhea) may not be detectable for up to 2 weeks 2, 3
• HIV may not be detectable for 6-12 weeks 2
• Syphilis may not be detectable for 6-12 weeks 1, 3

Behavioral Precautions

Advise abstaining from sexual activity until 7 days after completing prophylactic treatment (if given), or until repeat testing confirms no infection. 2 If she resumes sexual activity, consistent condom use is essential until all follow-up testing is complete. 1

Psychological Support

Referral to Sexual Assault Referral Centre (SARC) or equivalent counseling services is not optional—it should be strongly encouraged as part of standard care. 1 Responses to assault vary, and ongoing psychological support improves outcomes. 1

Common Pitfalls to Avoid

The most critical error is testing once at 1 week and assuming negative results exclude infection. 2 A negative test at 1 week does not rule out bacterial STIs (which need 2-week repeat) or blood-borne infections (which need 6-week and 3-month repeats). 2, 3

Do not rely solely on the patient's oral contraceptive use to exclude pregnancy risk. 1 Baseline and follow-up pregnancy testing is still indicated given the assault circumstances.

Failing to offer prophylactic treatment is a missed opportunity. 1 Even though the patient is asymptomatic, prophylaxis prevents potential complications (especially ascending pelvic infection from chlamydia/gonorrhea) and provides psychological reassurance. 1

Document clearly that physical examination was not performed due to telehealth limitations. 1 If any symptoms develop (vaginal discharge, pelvic pain, fever, lesions), in-person examination becomes necessary.