**Question:** Viruses causing hemorrhagic fever are-

A. Dengue virus
B. Ebola virus
C. Influenza virus
D. Hepatitis C virus

**Core Concept:** Hemorrhagic fever is a clinical syndrome characterized by severe bleeding, often accompanied by systemic inflammation and damage to multiple organs. It is caused by various viruses, bacteria, or parasites. Hemorrhagic fever viruses are particularly dangerous due to their potential to cause severe blood vessel damage, leading to excessive bleeding.

**Why the Correct Answer is Right:**

Correct Answer: Ebola virus (Option B)

Ebola virus is a member of the Filoviridae family and is responsible for causing Ebola virus disease (EVD), a severe hemorrhagic fever characterized by high mortality rates and systemic inflammation. EVD typically presents with fever, muscle pain, weakness, diarrhea, and bleeding manifestations. The virus targets and damages vascular endothelial cells, leading to leakage and bleeding.

**Why Each Wrong Option is Incorrect:**

A. Dengue virus (Option A) is responsible for dengue fever, not hemorrhagic fever. Although dengue is often associated with bleeding manifestations (e.g., petechiae, bleeding gums), it does not cause the severe hemorrhagic complications seen in hemorrhagic fever.

C. Influenza virus (Option C) primarily causes respiratory infections and is not associated with hemorrhagic fever. While influenza can lead to pneumonia and other organ involvement, it is not recognized for causing severe hemorrhagic complications.

D. Hepatitis C virus (Option D) primarily causes liver infections and liver diseases, such as hepatitis and cirrhosis. Hepatitis C virus does not typically lead to hemorrhagic fever and severe bleeding manifestations.

**Clinical Pearl:**

Understanding the differences between viral hemorrhagic fevers (such as Ebola and Marburg viruses) and other viral infections (e.g., influenza) is crucial for identifying the appropriate treatment and management strategies. Early recognition and isolation of patients with hemorrhagic fever are essential to prevent outbreaks and minimize transmission to healthcare workers.

In conclusion, the correct answer is Ebola virus (Option B) as it is the primary cause of hemorrhagic fever and exhibits severe vascular damage leading to bleeding manifestations. Understanding the differences between viral hemorrhagic fevers and other viral infections is crucial for appropriate management and prevention strategies.