The disease Kala-azar is spread by?

Appeared in: BSF Staff Nurse - 2015

Explanation

Kala-azar, also known as Visceral Leishmaniasis, is a protozoal disease caused by the parasite Leishmania donovani.
The disease is transmitted to humans through the bite of an infected female phlebotomine sand fly.
The sand fly acts as the biological vector, where the parasite develops before being transmitted during a blood meal.
In India, the primary vector for Kala-azar is the sand fly species Phlebotomus argentipes.

Option B: Butterflies are insects that primarily feed on nectar from flowers and are not blood-sucking. They are not vectors for any human diseases.
Option C: House flies are mechanical vectors, meaning they can carry pathogens on their bodies and transfer them to food or surfaces. They are associated with diseases like cholera and typhoid, not Kala-azar, which requires a biological vector.
Option D: Bed bugs are nuisance pests that cause significant discomfort and allergic reactions from their bites, but they are not considered competent vectors for transmitting diseases to humans.

Clinical Relevance

Nursing practice connection: Knowing Vector-borne disease transmission helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Nurses are vital in educating communities in endemic areas about vector control measures, such as using insecticide-treated bed nets, applying insect repellent, and maintaining environmental sanitation to reduce sand fly breeding sites.
During patient care, nurses must monitor for key signs of Kala-azar, including prolonged fever, splenomegaly, and weight loss, and report them for timely diagnosis.
When administering treatments like liposomal Amphotericin B, nurses must closely monitor for adverse reactions, such as infusion-related fever, chills, and potential nephrotoxicity.

How to Approach the Question

First, identify the key terms in the question: 'Kala-azar' and 'spread by'. This is a direct recall question asking for the vector of a specific disease.
Access your knowledge base on communicable diseases and their modes of transmission, particularly those prevalent in the Indian subcontinent.
Evaluate each option based on its known role as a disease vector.
Option A, Sand fly, is a known vector for Leishmaniasis (Kala-azar).
Options B, C, and D (Butterfly, House fly, Bed bug) are either not vectors or are associated with different types of diseases and transmission mechanisms.
Conclude that the sand fly is the specific vector responsible for transmitting Kala-azar.

Concept Tested & Keywords

QCE39mEVN8l5BEBVot5rX2

E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart B (pp 202-403 of 604) p. 169-171

E6 Ghai Essential Pediatrics(pp 26-904 of 913) p. 279-281

Practise the full BSF Staff Nurse - 2015

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