HIV Exposure

1. See Also
   1. HIV Transmission
   2. Sexually Transmitted Disease
   3. Bloodborne Pathogen Exposure
   4. Rape Management
2. Risk Factors: Exposure Source
   1. See HIV Risk Factor
3. Epidemiology: Risk of HIV Infection after single exposure
   1. Transfusion of HIV positive blood: >90%
      1. U.S. Risk: less than 1 per 100,000 transfusions are HIV contaminated
   2. Percutaneous needle stick: 0.3%
   3. Receptive anal intercourse: 0.5%
   4. Receptive vaginal intercourse: 0.1%
   5. Insertive intercourse: 0.05 to 0.07%
   6. Oral intercourse: 0.005 to 0.01%
   7. Blood to mucous membrane: 0.09%
   8. Blood to non-intact skin: <0.1%
   9. Maternal to fetal vertical transmission: 13-39% if no intrapartum AZT
4. Indications: Postexposure prophylaxis
   1. Occupational HIV Exposure (needle stick)
   2. Non-occupational HIV Exposure
      1. Isolated high risk exposure within last 72 hours
      2. Exposure to HIV positive or high risk sexual partner
5. Evaluation: Define the source patient status
   1. Unknown source
   2. HIV status unknown
   3. HIV negative
   4. HIV positive Class I
      1. Asymptomatic HIV or
      2. HIV Viral Load <1500 RNA copies/ml
   5. HIV positive Class II
      1. Symptomatic HIV Infection or
      2. AIDS or
      3. Acute seroconversion or
      4. HIV Viral Load >1500 RNA copies/ml
6. Precautions
   1. All post-exposure protocols have significant risks
      1. Serious potential adverse effects (some are life threatening)
      2. Serious drug interactions (some are life threatening)
   2. Consultation with local HIV experts is recommended unless treating physician is comfortable with these protocols and medications
7. Evaluation: Define the needle stick exposure severity
   1. Less severe
      1. Solid needle exposure or
      2. Superficial injury
   2. More severe
      1. Large bore hollow needle or
      2. Deep needle puncture or
      3. Visible blood on device or
      4. Needle used in patient's artery or vein
8. Protocol: Post-exposure Prophylaxis following NEEDLE STICK
   1. Source HIV positive Class I (asymptomatic, viral load <1500)
      1. LESS SEVERE: Basic 2 drug post-exposure prophylaxis
      2. MORE SEVERE: Expanded 3 drug post-exposure prophylaxis
   2. Source HIV positive Class II (symptomatic, AIDS, acute seroconversion, viral load >1500)
      1. Expanded 3 drug post-exposure prophylaxis
   3. Source HIV STATUS UNKNOWN or unknown source (regardless of exposure severity)
      1. HIGH RISK patient or community: Consider basic 2 drug post-exposure prophylaxis
      2. LOW RISK patient or community: No post-exposure prophylaxis
9. Protocol: Post-exposure prophylaxis following MUCOUS MEMRANE exposure and NON-INTACT SKIN exposure (e.g. dermatitis, open wound)
   1. Source HIV positive Class I (aymptomatic and viral load <1500)
      1. SMALL VOLUME exposure: Consider basic 2 drug post-exposure prophylaxis
      2. LARGE VOLUME exposure: Basic 2 drug post-exposure prophylaxis
   2. Source HIV positive Class II (symptomatic, AIDS, acute seroconversion, viral load>1500)
      1. SMALL VOLUME exposure: Basic 2 drug post-exposure prophylaxis
      2. LARGE VOLUME exposure: Expanded 3 drug post-exposure prophylaxis
   3. Source HIV STATUS UNKNOWN or unknown source
      1. HIGH RISK patient or community AND LARGE VOLUME exposure: Consider basic 2 drug post-exposure prophylaxis
      2. LOW RISK patient or community OR SMALL VOLUME exposure: No post-exposure prophylaxis
10. Protocol: Medications (2 and 3 drug protocols)
    1. Precaution
       1. Antiretrovirals have serious side effects and require discussion of risks prior to starting
       2. All drug 1 and drug 2 options cause Lactic Acidosis and hepatitic Steatosis
    2. Course
       1. Start within hours of exposure (within 24 to 36 hours)
       2. Continue for 4 weeks
    3. Drug 1 (choose one)
       1. Preferred
          1. Zidovudine (ZDV, AZT, Retrovir) 300 mg po bid (or 200 mg po tid)
          2. Tenofovir (TDF, Viread) 300 mg po daily
       2. Alternative
          1. Stavudine (d4T, Zerit) 40 mg po bid (30 mg bid for <60 kg adult or for toxicity)
          2. Didanosine (ddI, Didanosine) 400 mg po daily or 200 mg po bid (250 mg daily or 125 mg bid if <60 kg adult)
             1. Typically avoid ddI due to toxicity
    4. Drug 2 (choose one)
       1. Emtricitabine (FTC, Emtriva) 200 mg po daily
       2. Lamivudine (3TC) 300 mg PO daily (or 150 mg po bid)
    5. Drug 3 (choose one and add to regimen if the expanded 3 drug regimen is indicated)
       1. Preferred
          1. Lopinavir-Ritonavir (LPV/RTV, LPV/r, Kaletra) 400/100 po bid
       2. Alternative - without Ritonavir (RTV) combination
          1. Atazanavir (Reyataz, ATV) 400 mg po daily
          2. Fosamprenavir (FPV, Lexiva, Telzir, FOSAPV) 1400 mg po bid
          3. Nelfinavir (NFV, Viracept) 1250 mg po bid
          4. Efavirenz (Sustiva, EFV) 600 mg po qhs
       3. Alternative - with Ritonavir (RTV) combination
          1. Atazanavir-Ritonavir (Reyataz/RTV, ATV/r) 300/100 mg po daily
          2. Fosamprenavir-Ritonavir (Lexiva/RTV, FPV/r, FOSAPV/r) 1400/200 mg po daily (or 700/100 po bid)
          3. Indinavir-Ritonavir (IDV/RTV, IDV/r) 800/100 mg po bid
          4. Saquinavir-Ritonavir (SQV/RTV, SQV/r) 1000/100 mg po bid
    6. Combinations (combines Drugs 1 and 2)
       1. Combivir (AZT 300 + 3TC 150) one bid
       2. Truvada (TDF 300 + FTC 200) one daily
11. Lab: Monitoring - obtain baseline labs to monitor for adverse reaction
    1. Pregnancy Test
    2. Complete Blood Count with differential and platelets
    3. Urinalysis
    4. Renal Function tests
       1. Blood Urea Nitrogen (BUN)
       2. Serum Creatinine
    5. Liver Function Tests
       1. Aspartate Aminotransferase
       2. Alanine Aminotransferase
       3. Alkaline Phosphatase
       4. Total Bilirubin
12. Lab: Monitoring - follow-up
    1. Follow-up weekly during protocol
13. Management: Consultation Indications
    1. Treating clinician without experience using these medications or protocols
    2. Delayed exposure report beyond optimal 24-36 hour time frame
    3. Unknown source
    4. Exposed patient is pregnant or lactating
    5. Source patient is known to be resistant to certain Antiretroviral agents
    6. Adverse effects of Antiretroviral agents limiting use
14. Efficacy
    1. Zidovudine alone: 81% reduction in HIV seroconversion
       1. Zidovudine not used alone anymore due to resistance
       2. Cardo (1997) N Engl J Med 337:1485-90
15. Resources
    1. National HIV Clinicians Consultation Center
       1. http://www.ucsf.edu/hivcntr/Hotlines/PEPline.html
       2. Phone (PepLine): 1-888-HIV-4911 or 888-448-4911 (health care providers only)
16. Reference
    1. (2005) MMWR Morb Mortal Wkly Rep 54: (RR-9): 1-17
    2. (1996) MMWR Morb Mortal Wkly Rep 45:468-72
    3. (2001) MMWR Morb Mortal Wkly Rep 50(RR-11):24-25
    4. Merchant (2000) Ann Emerg Med 36:371