Flaviviridae taxonomy — Which viruses are members of the family Flaviviridae? (Select the option that correctly groups members.)

Introduction:
Accurate viral classification is important for understanding transmission, pathogenesis, and antiviral targets. Flaviviridae includes mosquito-borne flaviviruses and the hepaciviruses, with important human pathogens across both genera.

Given Data / Assumptions:

• Rubella is listed alongside Yellow fever virus and Hepatitis C virus.
• The family Flaviviridae comprises genera such as Flavivirus and Hepacivirus.
• Only one option should be entirely correct.

Concept / Approach:
Yellow fever virus is a prototypic Flavivirus. Hepatitis C virus belongs to the genus Hepacivirus within Flaviviridae. Rubella virus, however, is a Rubivirus placed in the Togaviridae family, not Flaviviridae. Therefore the correct grouping must include Yellow fever and Hepatitis C but exclude Rubella.

Step-by-Step Solution:

Verification / Alternative check:
Standard taxonomy charts list Flaviviridae members such as dengue, yellow fever, West Nile, Zika (Flavivirus) and hepatitis C (Hepacivirus). Rubella is separated under Togaviridae.

Why Other Options Are Wrong:

• Rubella virus only: wrong family.
• Yellow fever virus only: incomplete because it omits Hepatitis C virus.
• Hepatitis C virus only: incomplete because it omits Yellow fever virus.
• None of these: incorrect because two members are indeed Flaviviridae.

Common Pitfalls:
Memorizing only arthropod-borne members and forgetting that Hepatitis C is also in Flaviviridae.

Final Answer:
Both Yellow fever virus and Hepatitis C virus