**Question:** Route of transmission of Hepatitis E virus is:

A. Oral-fecal
B. Transfusion
C. Vertical
D. Blood products

**Core Concept:**
Hepatitis E virus (HEV) is an RNA virus that primarily affects the liver and can cause acute hepatitis. The virus primarily spreads through the fecal-oral route, although other modes of transmission do exist.

**Why the Correct Answer is Right:**
Hepatitis E virus is primarily transmitted through the consumption of contaminated water or food, specifically fecal matter. This route is known as oral-fecal transmission. The correct answer, A, represents this mode of transmission accurately.

**Why Each Wrong Option is Incorrect:**
B. Transfusion: HEV transmission via blood transfusion is considered rare, as the virus is not commonly found in blood donors. However, this option is incorrect because it does not represent the primary mode of transmission.
C. Vertical: Vertical transmission, i.e., from mother to child, is not the primary mode of HEV transmission, and option C is incorrect.
D. Blood products: Although HEV can occasionally be transmitted through blood products, this is less common than oral-fecal transmission. Option D is incorrect due to focusing on a less common mode of transmission.

**Clinical Pearl / High-Yield Fact:**
The high prevalence of HEV in endemic regions, such as parts of Asia and Africa, highlights the importance of proper sanitation and hygiene to prevent the spread of this virus. Ingestion of contaminated water or food is the primary mode of transmission, emphasizing the significance of safe water and food practices in preventing HEV infection.