# AI advises a healthcare worker after needle-stick injury to 'wait for the source patient's HIV test result' before starting PEP

- **ID:** `medical/needle-stick-hiv-pep-delay`
- **Domain:** medical
- **Category:** data_error
- **Error Code:** `CDC-2023-PEP`
- **Verification:** ai_generated
- **Fix Rate:** 83%

## Root Cause

Post-exposure prophylaxis (PEP) for HIV must be started within 72 hours of exposure, ideally within 4 hours. Delaying PEP to wait for source patient test results—especially if the source is high-risk (e.g., IV drug user, unknown status)—wastes critical time. CDC guidelines recommend starting empiric PEP immediately if source is high-risk or status unknown, and stopping only if source tests negative.

## Workarounds

1. **Immediately after needle-stick injury: wash wound with soap and water (don't scrub), flush mucous membranes with water. Go to occupational health or ED within 4 hours. Start empiric PEP (e.g., tenofovir disoproxil fumarate 300 mg + emtricitabine 200 mg once daily, plus raltegravir 400 mg twice daily or dolutegravir 50 mg once daily) if source is high-risk or unknown. Obtain source patient's consent for HIV testing, but do not delay PEP. If source tests negative (with fourth-generation antigen/antibody test), PEP can be stopped.** (90% success)
   ```
   Immediately after needle-stick injury: wash wound with soap and water (don't scrub), flush mucous membranes with water. Go to occupational health or ED within 4 hours. Start empiric PEP (e.g., tenofovir disoproxil fumarate 300 mg + emtricitabine 200 mg once daily, plus raltegravir 400 mg twice daily or dolutegravir 50 mg once daily) if source is high-risk or unknown. Obtain source patient's consent for HIV testing, but do not delay PEP. If source tests negative (with fourth-generation antigen/antibody test), PEP can be stopped.
   ```
2. **If source patient is unavailable or refuses testing, continue full 28-day PEP course. Offer HCW baseline HIV test, then follow-up testing at 6 weeks, 12 weeks, and 6 months post-exposure.** (85% success)
   ```
   If source patient is unavailable or refuses testing, continue full 28-day PEP course. Offer HCW baseline HIV test, then follow-up testing at 6 weeks, 12 weeks, and 6 months post-exposure.
   ```

## Dead Ends

- **Recommending to wait for source patient's rapid HIV test (e.g., fingerstick) before starting PEP** — Rapid tests have a window period (up to 3 months for some); a negative rapid test does not rule out acute HIV infection. PEP should start immediately if source is high-risk. (75% fail)
- **Telling HCW to 'just wash the wound and monitor for symptoms'** — Symptoms of acute HIV infection appear 2-4 weeks post-exposure; waiting for symptoms loses the window for PEP entirely. PEP is only effective if started before seroconversion. (90% fail)
- **Suggesting that PEP is only needed if the source patient is known to be HIV-positive** — Many source patients are unaware of their status; up to 40% of occupational HIV exposures are from unknown-status sources. Empiric PEP is standard in these cases. (80% fail)