What are the indications for post-exposure prophylaxis (PEP) for human immunodeficiency virus (HIV)?

Indications for HIV Post-Exposure Prophylaxis (PEP)

PEP should be initiated as soon as possible, ideally within 24 hours but no later than 72 hours after exposure, in any individual exposed to potentially infectious bodily fluids from a source known or reasonably suspected to be HIV-positive. 1

Core Requirements for PEP Eligibility

All three of the following criteria must be met 2:

• Timing: Exposure occurred within the past 72 hours (PEP is unlikely to be effective beyond this window) 2, 1
• Infectious fluid exposure: Contact with blood, blood-stained fluids, semen, vaginal/rectal secretions, breast milk, or cerebrospinal/amniotic/peritoneal/synovial/pericardial/pleural fluids 2
• HIV risk: Known or reasonable suspicion that the source person is HIV-positive 2

Types of Exposures Warranting PEP

Sexual Exposures 2, 1

• Receptive or insertive vaginal intercourse
• Receptive or insertive anal intercourse
• Receptive oral sex with ejaculation
• Contact with mucous membranes (vagina, rectum, mouth) by potentially infectious fluids 2

Parenteral Exposures 2

• Needlestick injuries with hollow-bore needles containing fresh blood 2
• Deep injuries with visible blood on the device 3
• Procedures involving needles placed in source patient's blood vessels 3
• Sharing injection drug equipment 2, 1

Mucous Membrane Exposures 2

• Splashes of blood or infectious fluids to eyes, nose, or oral cavity 2

Special Circumstances 2, 1

• Sexual assault cases (offer PEP promptly without waiting for complete risk assessment) 1
• Exposures where source HIV status is unknown but risk factors suggest possible infection 2

Exposures That Do NOT Require PEP

PEP should not be offered in the following situations 2:

• Exposed person is already HIV-positive 2, 1
• Source person is confirmed HIV-negative (using fourth-generation antigen/antibody test) 2
• Non-infectious bodily fluids: tears, non-blood-stained saliva, urine, sweat, feces, vomitus, sputum, or nasal secretions 2
• Found-needle injuries in public settings (no documented HIV transmissions from discarded needles exposed to drying) 2
• Exposure occurred more than 72 hours ago 2, 1

Risk Assessment Algorithm

Step 1: Determine Source HIV Status 2, 4

• If source is known HIV-positive → Proceed with PEP
• If source tests HIV-negative with fourth-generation test and no acute infection symptoms → PEP not indicated 2
• If source status unknown → Assess based on risk factors and local HIV prevalence 2

Step 2: Evaluate Exposure Type 3

Higher risk exposures include:

• Deep injuries 3
• Visible blood on device 3
• Terminal illness in source patient (higher viral load) 3
• Large-bore hollow needles 2

Step 3: Initiate PEP Without Delay 2, 1, 4

Do not wait for:

• HIV test results from exposed person 2, 4
• Source person HIV testing 4
• Complete risk factor assessment 4

Critical Timing Considerations

• Optimal window: Within 24 hours of exposure 1, 4
• Maximum window: Up to 72 hours post-exposure 2, 1
• Beyond 72 hours: PEP is not recommended as efficacy is negligible 2
• Delayed presentation: Expert consultation advised for cases presenting 24-36 hours after exposure 2

Common Pitfalls to Avoid

• Never delay PEP initiation while waiting for source person testing or detailed risk assessment 2, 4
• Do not test discarded needles for HIV contamination—base decisions on exposure type and epidemiology 4
• Avoid overestimating risk from found needles in public settings (no documented transmissions) 2
• Do not withhold PEP in sexual assault cases due to incomplete information 1
• Remember that PEP can be discontinued if the exposed person is later found to be HIV-positive or if source is confirmed negative 2

High-Risk Populations Requiring Special Attention

Individuals with ongoing risk factors who may benefit from transitioning to PrEP after completing PEP 2, 1:

• Persons who have used PEP in the past year 2
• Those with repeated sexual or injection drug use exposures 2, 1
• Sexual partners of HIV-positive individuals 2