Question

In which of the following tissue, rabies viruses multiply in bats?

• A. Brain tissue
• B. Fatty tissue
• C. Muscle
• D. Spinal tissue

Hint:

In bats, the rabies virus has a unique reservoir site: Brown Adipose Tissue (Brown Fat).
This tissue allows the virus to survive and persist during periods of hibernation when the bat's metabolism is suppressed.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The rabies virus, a member of the genus *Lyssavirus* (family *Rhabdoviridae*), is a neurotropic virus that infects all warm-blooded animals.
While the virus primarily replicates in the central nervous system (CNS) and salivary glands of most mammals, its pathogenesis in bats has unique characteristics.

Step 2: Detailed Explanation:
In insectivorous and frugivorous bats, the rabies virus exhibits a unique tissue tropism.
In addition to replicating in the brain (CNS) and salivary glands, the rabies virus replicates and persists in the brown adipose tissue (brown fat or fatty tissue).
Brown adipose tissue is highly vascularized and metabolically active, serving as a key site for thermogenesis in hibernating bats.
The virus can replicate in this brown fat during both active periods and periods of torpor or hibernation.
This unique tissue tropism allows the virus to remain latent or replicate slowly during winter hibernation without killing the host.
When the bat emerges from hibernation, the increased metabolic activity in the brown fat helps reactivate and spread the virus to the salivary glands, allowing transmission through bites.
Therefore, brown adipose tissue (fatty tissue) is a vital reservoir site for rabies virus multiplication and persistence in bats.

Step 3: Final Answer:
The correct option is (B).