Following diseases are transmitted by culex mosquito except

Appeared in: UPPSC 2022

Explanation

Rift Valley Fever (RVF) is the correct answer as it is the only disease in the list not primarily transmitted by Culex mosquitoes.
RVF is a viral zoonosis, and its primary vectors are mosquitoes from the Aedes genus.
While Culex mosquitoes can sometimes transmit RVF during large epidemics, they are not the main vector, making RVF the exception among the choices.
The other three options—Japanese encephalitis, Filariasis, and West Nile fever—all have Culex mosquitoes as their principal vector.

Option A: This is incorrect because Japanese encephalitis is a well-known disease transmitted by Culex mosquitoes, specifically Culex tritaeniorhynchus, which thrive in rice paddies.
Option B: This is incorrect. Lymphatic filariasis (caused by Wuchereria bancrofti) is primarily transmitted by Culex quinquefasciatus mosquitoes in many urban and semi-urban parts of the world.
Option C: This is incorrect because West Nile fever virus is transmitted to humans principally by mosquitoes of the Culex genus, which become infected when they feed on infected birds.

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 the specific vector for a disease is critical for community health nurses to design and implement effective vector control strategies. For example, controlling Culex involves managing polluted stagnant water, while controlling Aedes involves managing clean water storage.
This knowledge helps in differential diagnosis. A patient's travel history and the local mosquito population can provide clues to the potential cause of a fever.
What if? If a community reports a sudden increase in dead birds followed by human cases of fever and encephalitis, a nurse should suspect a West Nile Virus (Culex-borne) outbreak and initiate surveillance and public education on avoiding mosquito bites, especially during evening and dawn.

How to Approach the Question

First, identify the keyword 'except' in the question. This tells you that three of the options are transmitted by Culex mosquitoes, and you need to find the one that is not.
Review the stem of the question, which focuses on 'culex mosquito' as the vector.
Systematically evaluate each option by recalling the primary mosquito vector for that disease.
Ask yourself for each option: 'Is this disease transmitted by Culex?'
Japanese encephalitis? Yes. Filariasis? Yes. West Nile fever? Yes.
Rift Valley fever? No, it's primarily Aedes. This is the outlier.

Concept Tested & Keywords

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart B (pp 202-403 of 604) pp. 152-154, 133-135

Practise the full UPPSC 2022

Attempt every question from this paper in a timed mock, then review the full solution for each one.