Japanese Encephalitis is transmitted by
**Core Concept**
Japanese Encephalitis (JE) is a viral infection caused by the **Japanese Encephalitis virus**, primarily transmitted through the bite of an infected mosquito. The virus belongs to the **Flavivirus** genus, which also includes other notable pathogens like West Nile virus and Dengue virus.
**Why the Correct Answer is Right**
The correct answer is related to the primary vector responsible for transmitting the Japanese Encephalitis virus to humans. The **Culex** mosquito species, particularly **Culex tritaeniorhynchus**, is the main vector for JE virus transmission. When an infected mosquito feeds on the blood of a vertebrate host, such as pigs or birds, it ingests the virus, which then replicates within the mosquito before being transmitted to another host during a subsequent feeding.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because, although other mosquitoes can transmit diseases, they are not the primary vectors for Japanese Encephalitis.
**Option B:** Incorrect as it does not specify the correct vector.
**Option C:** Incorrect because, while ticks can transmit various diseases, Japanese Encephalitis is primarily mosquito-borne.
**Option D:** Incorrect as fleas are not the primary vectors for JE.
**Clinical Pearl / High-Yield Fact**
Japanese Encephalitis is a significant cause of encephalitis in Asia, and vaccination is a crucial preventive measure, especially for individuals living in or traveling to endemic areas.
**Correct Answer:** D. Culex mosquito