Culex is the vector that causes?

NHM UP Staff Nurse - 2017

Applied Microbiology & Infection control

Easy

Appeared in: NHM UP Staff Nurse - 2017

Explanation

The Culex genus of mosquitoes, particularly the species Culex tritaeniorhynchus, is the principal vector for the Japanese Encephalitis (JE) virus.
JE is a viral brain infection that is a leading cause of viral encephalitis in Asia.
The transmission cycle of JE primarily involves Culex mosquitoes, pigs (as amplifying hosts), and wading birds (as reservoir hosts), with humans being incidental hosts.
Among the given options, JE has the strongest and most classic association with the Culex genus as a primary vector.

Option A: Although Culex quinquefasciatus is a major vector for Bancroftian filariasis in urban India, filariasis is also transmitted by other mosquito genera like Anopheles and Mansonia. This makes the link less exclusive than the link between Culex and JE.
Option C: Dengue fever is transmitted by the Aedes aegypti mosquito, not Culex. Aedes mosquitoes are characterized by their black and white striped legs and are typically day-biting.
Option D: Yellow fever is also transmitted by the Aedes aegypti mosquito. It is a viral hemorrhagic disease found in tropical regions of Africa and the Americas.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Vector-borne diseases and their specific mosquito vectors as background academic context rather than a clinical decision trigger.
Understanding vector habits is crucial for targeted public health education. For JE (Culex), prevention focuses on using bed nets at night, controlling polluted water sources, and vaccination in endemic areas.
For diseases like Dengue (Aedes), prevention strategies emphasize eliminating clean water containers where mosquitoes breed and protecting against bites during the daytime.
A nurse's role includes educating communities about these differences to empower them to take appropriate preventive measures based on the prevalent diseases in their area.

How to Approach the Question

First, identify the keyword in the question stem, which is 'Culex'.
Recall the primary diseases associated with the Culex mosquito vector. The most common ones are Japanese Encephalitis and Filariasis.
Next, evaluate the given options. 'Dengue' and 'Yellow fever' are primarily transmitted by Aedes mosquitoes, so these options can be confidently eliminated.
You are left with 'Filariasis' and 'JE'. Both can be transmitted by Culex.
To make the final choice, consider the strength of the association. Filariasis is also transmitted by other genera (Anopheles, Mansonia), while JE is classically and most strongly associated with Culex. Therefore, JE is the best fit for this question.

Concept Tested & Keywords

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