When is the best time for a healthcare worker with a needlestick injury to start postexposure prophylaxis (PEP) for human immunodeficiency virus (HIV) prevention?

Initiating postexposure prophylaxis (PEP) for HIV infection as soon as possible after a needlestick injury is crucial. The most effective time frame for starting PEP is within 72 hours of exposure, but the ideal approach is to begin treatment immediately, as the effectiveness of PEP diminishes significantly the longer one waits.

The rationale behind immediate initiation is that it enhances the chances of preventing HIV infection in non-infected individuals who have been exposed to the virus. Delaying treatment could allow the virus to establish an infection, which is why immediate action is prioritized.

The window for efficacy of PEP typically extends to 72 hours, but urgent action reduces the risk of transmission more effectively than waiting. Thus, beginning PEP immediately is the recommended protocol to ensure optimal outcomes following potential exposure to HIV.