Specimens harboring HBV – Identify which body fluids/tissues may contain hepatitis B virus in an infected person.

Introduction:
Understanding which specimens can harbor hepatitis B virus (HBV) informs transmission risk, infection control, and counseling. HBV is a bloodborne virus, but infectious virions and HBsAg can also be present in other body fluids.

Given Data / Assumptions:

• HBV circulates at high titers in blood of infected persons, especially in HBeAg-positive states.
• Sexual transmission implicates semen and vaginal secretions.
• HBV DNA and HBsAg can be detected in saliva; although transmission risk is lower than blood exposure, presence is documented.

Concept / Approach:
List fluids with demonstrated HBV presence and potential infectivity. When multiple relevant specimens are enumerated (blood, semen, saliva), the comprehensive choice is “All of these.”

Step-by-Step Solution:
Step 1: Confirm blood as the principal reservoir for transmission (transfusion, needlesticks).Step 2: Confirm semen as a vehicle for sexual transmission.Step 3: Confirm detection of HBV markers in saliva, supporting potential albeit lower risk.Step 4: Choose the inclusive option.

Verification / Alternative check:
Infection control guidelines list blood and certain body fluids, including semen and, to a lesser extent, saliva, as relevant for HBV presence. Vaccination and standard precautions remain key.

Why Other Options Are Wrong:

• Single-fluid choices understate HBV distribution.
• None of these: contradicted by robust virologic evidence.

Common Pitfalls:
Assuming saliva cannot harbor HBV; ignoring that infectivity varies by fluid and viral load.

Final Answer:
All of these.