Needlestick Hepatitis Transmission — MFDS Part 1 MCQ

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ModerateMicrobiologyNeedlestick Hepatitis TransmissionMFDS Part 1

A susceptible, unvaccinated dental healthcare worker sustains a percutaneous sharps injury involving blood from a source known to carry the relevant virus. If no post-exposure prophylaxis is given, which hepatitis virus has the highest per-exposure transmission risk?

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Correct answer: B — Hepatitis B virus (HBV)

Hepatitis B virus is the most efficiently transmitted hepatitis virus following a contaminated sharps injury. UKHSA quotes an approximate transmission risk of 1 in 3 from a known infected source, compared with about 1 in 30 for HCV. The actual risk varies with source viral load, injury depth and the amount of blood transferred. HAV and HEV are predominantly enterically or foodborne rather than occupational sharps pathogens. Although HDV can be bloodborne, it requires concomitant HBV infection for replication and is not the independent best answer. Hepatitis B immunisation substantially reduces occupational risk, which is why the stem specifies a susceptible, unvaccinated worker without post-exposure prophylaxis.

Reference: UK Health Security Agency. Management of bloodborne virus risk in bomb blast victims (hepatitis B, C and HIV), Key facts. Updated 16 July 2026. https://www.gov.uk/government/publications/bloodborne-viruses-managing-risk-in-bomb-blast-victims/management-of-bloodborne-virus-bbv-risk-in-bomb-blast-victims-hepatitis-b-c-and-hiv