HIV and STI Testing Requirements for PrEP in Australia's PBS
HIV and STI testing for PrEP through Australia's Pharmaceutical Benefits Scheme (PBS) requires HIV testing every 3 months, STI screening every 3 months, and kidney function monitoring at baseline and every 6 months.
Initial Testing Requirements Before Starting PrEP
Mandatory Tests
- HIV testing: A negative HIV test is mandatory before initiating PrEP, preferably using a combination antigen-antibody assay (4th generation test) 1, 2
- Serum creatinine and estimated glomerular filtration rate: Must be performed within 7 days before starting PrEP 1, 2
- Hepatitis B surface antigen (HBsAg): Required to assess for active hepatitis B infection 1, 2
- STI screening: Comprehensive testing for gonorrhea and chlamydia (at all relevant anatomical sites based on sexual practices) and syphilis serology 1
- Pregnancy test: Required for women before initiating PrEP 2
Additional Baseline Testing
- Hepatitis C antibody: Recommended, especially for high-risk individuals 1
- HIV RNA testing: Should be performed if acute HIV infection is suspected 1
Ongoing Monitoring Requirements
HIV Testing
- Frequency: Every 3 months 1, 2
- Test type: Laboratory-based HIV antibody and antigen test 1, 2
- Prescription limits: PrEP prescriptions should not exceed 90 days without interval HIV testing 1
STI Screening
- Frequency: Every 3 months 1, 2
- Tests included:
- Gonorrhea and chlamydia nucleic acid amplification tests (genital and non-genital sites)
- Syphilis serology
- Hepatitis C antibody (annually, or more frequently for high-risk individuals) 1
Kidney Function Monitoring
- Frequency: At least every 6 months 1, 2
- More frequent monitoring: Required for patients >50 years old, those with baseline creatinine clearance <90 mL/min, or those with hypertension or diabetes 1
Special Considerations
First Follow-up Visit
- A follow-up visit 30 days after PrEP initiation is recommended for:
- HIV testing
- Assessment of adverse effects
- Adherence support 1
Rapid PrEP Initiation
- If a negative HIV test result is available from within the past 7 days, PrEP can be initiated at the first visit (same day) 1
- If no recent test result is available, a rapid point-of-care test should be performed, and PrEP started only if negative 1
Hepatitis B Monitoring
- For individuals with active HBV infection, careful monitoring of liver function is required when starting or stopping PrEP due to risk of hepatitis flares 1
Implementation Challenges
Despite clear guidelines, adherence to testing protocols in Australia has been suboptimal:
- Studies show only 35% of MSM receive annual HIV testing as recommended 3
- Among higher-risk MSM, only 15% receive 6-monthly HIV testing 3
Clinical Pearls
- Documentation: Always document HIV status before each PrEP prescription renewal
- Adherence support: Use each follow-up visit to assess and address barriers to PrEP adherence 1
- Comprehensive prevention: Deliver PrEP as part of a comprehensive prevention package including risk-reduction counseling 2
- Consider DoxyPEP: For cisgender men who have sex with men and transgender women, doxycycline post-exposure prophylaxis (200mg within 72 hours after condomless sex) can be considered to reduce bacterial STI incidence 2
By following these testing requirements, healthcare providers can ensure safe and effective PrEP provision while monitoring for HIV, STIs, and potential adverse effects of medication.