Question

African swine fever causes huge mortality in pigs. The disease is caused by

• A. Picornavirus
• B. Pestivirus
• C. Influenza virus
• D. Iridovirus

Hint:

Do not confuse Classical Swine Fever (caused by a Pestivirus) with African Swine Fever (historically grouped under Iridovirus, now in its own family Asfarviridae).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
African Swine Fever (ASF) is a highly contagious, severe hemorrhagic viral disease affecting domestic and wild pigs, causing mortality rates approaching 100%.

Step 2: Detailed Explanation:
The African Swine Fever Virus (ASFV) is a large, double-stranded DNA virus.
Historically, due to its icosahedral symmetry, large DNA genome, and cytoplasmic replication, ASFV was classified under the family Iridoviridae (Iridoviruses).
Although modern molecular virology has reclassified ASFV into its own unique family, Asfarviridae (of which it is the sole member), older classic veterinary curricula and competitive exams still categorize or associate it with the Iridovirus group due to these historical taxonomic and morphological similarities.
Let us review the other options:
- Picornavirus is a small, single-stranded RNA virus family causing diseases like Foot-and-Mouth Disease (FMD) and Swine Vesicular Disease.
- Pestivirus (family Flaviviridae) causes Classical Swine Fever (Hog Cholera) and Bovine Viral Diarrhea (BVD).
- Influenza virus causes Swine Influenza.
Therefore, ASFV is historically and morphologically associated with the Iridoviruses.

Step 3: Final Answer:
The disease is caused by an Iridovirus (specifically Asfarviridae), which corresponds to option (D).