Parenteral transmission: Which of the following hepatitis viruses can be transmitted by parenteral exposure?

Introduction:
Parenteral transmission includes transfusion, needle sharing, and percutaneous exposures. Several hepatitis viruses spread efficiently by these routes, with implications for screening and infection control.

Given Data / Assumptions:

• The listed viruses are HBV, HCV, and HDV.
• We seek which are transmissible through parenteral exposure.

Concept / Approach:
HBV and HCV are archetypal blood-borne pathogens. HDV is a defective RNA virus that requires HBV for replication; its spread mirrors HBV, including parenteral exposure. Therefore all listed viruses can be parenterally transmitted.

Step-by-Step Solution:
Confirm HBV and HCV parenteral routes (widely documented). Recognize HDV co-transmission with HBV through the same exposures. Choose the inclusive option that captures all three.

Verification / Alternative check:
Blood bank screening, harm reduction, and vaccination strategies target these agents specifically due to parenteral risk.

Why Other Options Are Wrong:

• Any single-virus option: Incomplete; all three are parenterally transmissible.
• None of these: Contradicted by extensive epidemiology.

Common Pitfalls:
Overlooking HDV because it is dependent on HBV; dependence does not negate its parenteral spread when HBV is present.

Final Answer:
All of these are transmitted by parenteral routes.