What screening is recommended prior to starting Pre-Exposure Prophylaxis (PrEP)?

Recommended Screening Prior to Starting Pre-Exposure Prophylaxis (PrEP)

Before initiating PrEP, mandatory screening includes HIV testing (preferably with a combination antigen-antibody assay), serum creatinine with estimated glomerular filtration rate, and hepatitis B surface antigen testing. 1

Essential Laboratory Testing

HIV Testing

• HIV testing using a combination antigen-antibody assay is mandatory to confirm HIV-seronegative status 1
• If acute HIV infection is suspected, HIV RNA testing should be obtained 1
• Oral fluid-based rapid HIV tests are not recommended due to lower sensitivity for detecting acute or recent infection 2
• For high-risk populations with recent exposure, consider adding HIV RNA testing to exclude acute HIV infection 1

Kidney Function Assessment

• Serum creatinine measurement and estimated glomerular filtration rate determination 1
• TDF-based PrEP is contraindicated in persons with creatinine clearance below 60 mL/min/1.73m² 1

Hepatitis Testing

• Hepatitis B surface antigen (HBsAg) testing is required 1
• Special consideration for patients with active HBV infection as discontinuation of TDF/emtricitabine could lead to acute HBV flares or hepatic decompensation 1
• Hepatitis C serologic testing should be performed at baseline 1

STI Screening

• Comprehensive STI screening including:
  • Syphilis serology
  • Nucleic acid amplification testing for chlamydia and gonorrhea at appropriate anatomical sites (oral, rectal, urine, vaginal) based on exposure history 1
  • Any identified STIs should be treated 1

Additional Assessments

Vaccination Status

• Assess and provide vaccination against:
  • Hepatitis A and B for those not immune 1
  • Human papillomavirus for eligible individuals (women aged 13-26 years and men aged 13-21 years who haven't completed the series) 1

Pregnancy Testing

• Pregnancy testing for women of childbearing potential 1

Risk Assessment

• Evaluation of HIV risk factors to confirm PrEP indication (recommended for populations with annual HIV incidence of at least 2%) 1
• Discussion of adherence capacity and potential barriers 1

Follow-Up Protocol

• Initial follow-up visit 30 days after PrEP initiation for HIV testing, adverse effects assessment, and adherence support 1
• Subsequent follow-up every 3 months for:
  • HIV testing (using combination antigen-antibody assay)
  • STI screening
  • Adherence assessment and support 1
• Creatinine level measurement at least every 6 months, more frequently for higher-risk patients (>50 years, taking hypertension or diabetes medications, or with GFR <90 mL/min) 1
• PrEP prescriptions should not exceed 90 days without interval HIV testing 1

Important Considerations and Pitfalls

Avoiding Missed Acute HIV Infection

• Careful exclusion of primary HIV infection before starting PrEP is crucial as initiating PrEP during undiagnosed acute infection can lead to drug resistance 3
• Be aware that PrEP users who seroconvert may present with lower viral load peaks and fewer symptoms than typical primary HIV infection 3

Hepatitis B Management

• For patients with active HBV infection, discontinuation of TDF/emtricitabine PrEP requires careful monitoring of HBV infection and liver function 1
• Risk of hepatitis flare and hepatic decompensation is significant, particularly in patients with cirrhosis 1

Medication Selection

• Daily TDF/emtricitabine is the recommended regimen for all populations 1
• TDF/lamivudine, TAF/emtricitabine, and TDF alone are not recommended for PrEP 1
• A 1-week lead-in time with daily dosing is recommended before anticipated exposures 1

By following this comprehensive screening protocol before initiating PrEP, providers can ensure safe and effective HIV prevention while minimizing potential adverse effects and complications.