What causes Yellow Fever?

Appeared in: Uttarakhand CHO - 2021

Explanation

Yellow Fever is a viral hemorrhagic disease caused by the Yellow Fever virus, a member of the Flavivirus genus.
The virus is transmitted to humans primarily through the bite of infected mosquitoes, specifically the Aedes aegypti species in urban settings.
This makes 'Mosquitoes' the most specific and accurate answer for the transmission vector of the disease.

Option A: Flies are mechanical vectors for diseases like typhoid, cholera, and dysentery by contaminating food, but they are not the biological vector for the Yellow Fever virus.
Option B: Rats are reservoirs for diseases like plague (transmitted by fleas) and leptospirosis (transmitted through urine-contaminated water), but they do not transmit Yellow Fever.
Option C: While mosquitoes are insects, this option is too general and less precise. In medical and nursing questions, the most specific correct answer is preferred. Since 'Mosquitoes' is an option, it is the superior choice.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Vector-borne disease transmission as background academic context rather than a clinical decision trigger.
Nurses must be vigilant in identifying potential cases of Yellow Fever in travelers returning from endemic areas (Africa, South America) by recognizing key symptoms like sudden fever, chills, headache, and jaundice.
Patient education is a key nursing role, especially regarding the highly effective 17D vaccine, which provides lifelong immunity and is often required for international travel to at-risk countries.
What if? A patient presents with fever and jaundice but has no travel history to an endemic area. The nurse's assessment should prioritize other causes like viral hepatitis, leptospirosis, or dengue, as Yellow Fever would be highly unlikely.

How to Approach the Question

First, identify the core of the question: it asks for the cause or vector of Yellow Fever.
Recall or deduce that Yellow Fever is a well-known mosquito-borne illness.
Evaluate the options for specificity. 'Flies' and 'Rats' are incorrect vectors for this disease.
Compare 'Insects' and 'Mosquitoes'. Recognize that 'Mosquitoes' is a specific type of insect and is the most precise correct answer available.
Select the most specific and accurate option, which is a common principle in answering multiple-choice questions in nursing exams.

Concept Tested & Keywords

QyJSbxaBzVj8Sp76L8gq1X

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 2077-2079

E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart B (pp 202-403 of 604) p. 144-146

E6 Medicine Davidson Principles Practice 24e p. 264-266

Practise the full Uttarakhand CHO - 2021

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