KFD is caused by?
**Core Concept**
KFD, or Kyasanur Forest Disease, is a tick-borne viral hemorrhagic fever endemic to the Indian subcontinent. It is caused by a viral agent that affects the host's immune system and causes severe hemorrhagic manifestations.
**Why the Correct Answer is Right**
KFD is caused by the Kyasanur Forest Disease virus (KFDV), a member of the Flaviviridae family, which also includes other notable viruses like Zika and dengue fever. The KFDV is primarily transmitted through the bite of an infected tick, particularly the Haemaphysalis spinigera species. Upon infection, the virus targets the host's immune system, leading to the production of pro-inflammatory cytokines and the activation of the complement system, resulting in vascular damage and hemorrhage.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as KFD is not caused by a rickettsial agent like Coxiella burnetii, which causes Q fever.
**Option B:** This option is incorrect as KFD is not caused by a viral agent like Ebola, which is a distinct viral hemorrhagic fever endemic to Africa.
**Option C:** This option is incorrect as KFD is not caused by a bacterial agent like Leptospira, which causes leptospirosis, a different disease altogether.
**Clinical Pearl / High-Yield Fact**
It is essential to note that KFD is often misdiagnosed as malaria or dengue fever due to its similar clinical presentation. However, the presence of hemorrhagic manifestations and a significant elevation in liver enzymes can help differentiate KFD from these diseases.
**Correct Answer: D. Kyasanur Forest Disease virus (KFDV)**