What is the recommended post-exposure prophylaxis (PEP) for immediate treatment after potential exposure to infectious diseases such as Human Immunodeficiency Virus (HIV), hepatitis B, and rabies?

Post-Exposure Prophylaxis (PEP) for Infectious Diseases

Post-exposure prophylaxis requires immediate administration of specific medications based on the type of exposure, with HIV PEP requiring a three-drug regimen started within 72 hours, hepatitis B requiring HBIG plus vaccination within 24 hours, and rabies requiring both immunoglobulin and vaccination series. 1

General Principles of PEP

• PEP should be initiated as soon as possible after exposure
• Immediate care to exposure site: wash wounds with soap and water, flush mucous membranes with water 1
• Evaluate the source of exposure when possible (test for HIV, HBV, HCV)
• Assess risk based on type of fluid and exposure route

HIV Post-Exposure Prophylaxis

Timing and Indications

• Start PEP as soon as possible, ideally within 24 hours and no later than 72 hours 2, 3
• PEP is recommended for significant exposures to HIV-positive or high-risk unknown sources
• Risk assessment should consider:
  • Type of exposure (percutaneous, mucous membrane, non-intact skin)
  • Type of body fluid (blood, visibly bloody fluids, potentially infectious fluids)
  • HIV status and viral load of source person

Recommended Regimen

• Current recommendation: Three-drug antiretroviral regimen for all occupational exposures to HIV 3
• Traditional basic regimen includes:
  • Zidovudine (ZDV) 600mg daily in 2-3 divided doses + Lamivudine (3TC) 150mg twice daily (available as Combivir) 1
• Duration: 28 days (4 weeks) 3

Monitoring and Follow-up

• Follow-up should begin within 72 hours of exposure 3
• HIV testing schedule: baseline, 6 weeks, 3 months, and 6 months 2
• If using newer fourth-generation combination HIV tests, testing may conclude at 4 months 3
• Monitor for drug toxicity and adverse effects
• Common side effects include nausea (57%), fatigue (38%), headache (18%), vomiting (16%), and diarrhea (14%) 4

Hepatitis B Post-Exposure Prophylaxis

Timing and Indications

• Administer PEP as soon as possible after exposure, preferably within 24 hours 1, 5
• Efficacy decreases markedly if delayed beyond 48 hours 5

Recommended Regimen

• For unvaccinated individuals exposed to HBsAg-positive source:
  • Hepatitis B Immune Globulin (HBIG) 0.06 mL/kg IM immediately + initiate HB vaccine series 5
• For vaccinated individuals with inadequate antibody response:
  • HBIG immediately + HB vaccine booster dose, or
  • Two doses of HBIG, one immediately and one 1 month later 5
• For perinatal exposure to HBsAg-positive mothers:
  • HBIG 0.5 mL IM within 12 hours of birth + complete HB vaccine series (first dose within 7 days) 5
• For sexual exposure to HBsAg-positive person:
  • HBIG 0.06 mL/kg + begin HB vaccine series within 14 days of last sexual contact 5

Follow-up

• Test for anti-HBs 1-2 months after last vaccine dose 1
• If HBIG was received, anti-HBs response cannot be ascertained for 3-4 months 1

Hepatitis C Post-Exposure Prophylaxis

• No PEP is currently recommended for HCV exposure 1
• Perform baseline and follow-up testing for anti-HCV and ALT at 4-6 months
• Consider HCV RNA testing at 4-6 weeks for earlier diagnosis 1

Rabies Post-Exposure Prophylaxis

While not extensively covered in the provided evidence, rabies PEP typically consists of:

• Rabies immune globulin infiltrated into wound
• Rabies vaccination series (days 0,3,7,14)
• Should be started immediately after exposure

Important Considerations and Pitfalls

Common Pitfalls

1. Delayed initiation of PEP

   • HIV PEP efficacy decreases significantly after 72 hours
   • HBV PEP efficacy decreases markedly after 48 hours

2. Incomplete adherence to PEP regimens

   • Only 43% of healthcare workers complete HIV PEP as initially prescribed 4
   • Side effects are the most common reason for discontinuation (54%) 4

3. Inadequate follow-up

   • Establish a system to encourage exposed persons to return for follow-up testing 1
   • Provide counseling about preventing secondary transmission during follow-up period

Risk Reduction Strategies

• Manage side effects proactively with antimotility and antiemetic agents 1
• Consider modifying dose intervals to improve tolerability
• Provide medication adherence counseling
• Ensure access to expert consultation for complex cases

Institutional Preparedness

• Establish a written bloodborne pathogen policy
• Ensure 24/7 availability of PEP medications
• Develop laboratory capacity for rapid testing
• Train personnel on exposure management protocols
• Create systems for monitoring and evaluating exposure management programs 1

Remember that PEP is an emergency intervention that should be part of a comprehensive approach to preventing infectious disease transmission. Prompt administration of appropriate PEP can significantly reduce the risk of infection following exposure to bloodborne pathogens.