Which bloodborne pathogen carries the HIGHEST risk of transmission to a dental health care worker following a percutaneous needlestick from an infected source?

Correct answer: B. Hepatitis B virus

• A. HIV transmission after percutaneous exposure is approximately 0.3% — the lowest of the three, despite being the most feared.
• B. Correct. HEPATITIS B is the most transmissible of the bloodborne pathogens after needlestick exposure — roughly 30% (up to ~6–30% depending on source e-antigen status), versus about 1.8% for HCV and 0.3% for HIV. HBV also survives on environmental surfaces for days. This is precisely why HBV vaccination is mandatory for dental personnel.
• C. Hepatitis A is transmitted by the fecal–oral route, not by blood, and is not an occupational bloodborne risk.
• D. Hepatitis C transmission after needlestick is approximately 1.8% — real, but an order of magnitude below HBV, and there is no vaccine.