Hepatitis G virus (GBV-C/HPgV) – Transmission routes: Identify the correct mode(s) of transmission documented for this agent.

Introduction:
Hepatitis G virus, now often termed GBV-C or human pegivirus (HPgV), is detected in blood donors, persons with parenteral exposures, and some sexually exposed populations. This question checks recognition of the principal transmission routes implicated for this virus.

Given Data / Assumptions:

• HPgV/GBV-C is found in the bloodstream and can be transmitted via contaminated needles or transfusion.
• Sexual transmission has been documented.
• There is no strong evidence of purely fecal–oral transmission analogous to HAV.

Concept / Approach:
Align epidemiologic patterns with transmission modes. Bloodborne and sexual routes mirror those of HBV/HCV to varying extents. Therefore, when options list parenteral and sexual routes, selecting both is appropriate.

Step-by-Step Solution:
Step 1: Associate detection in blood donors and IV drug users with parenteral spread.Step 2: Review studies indicating sexual transmission.Step 3: Exclude exclusive fecal–oral spread given limited supportive evidence.Step 4: Select “Both (a) and (b).”

Verification / Alternative check:
Seroprevalence studies and transfusion-screening data support bloodborne spread; cohort data support sexual transmission components.

Why Other Options Are Wrong:

• Parenteral only or sexual only: incomplete.
• None of these: contradicted by epidemiologic evidence.
• Fecal–oral only: not the principal route for HPgV.

Common Pitfalls:
Assuming “hepatitis” always implies fecal–oral spread; conflating HAV/HEV with bloodborne agents.

Final Answer:
Both (a) and (b).