The main cause of plague is?

Appeared in: BSF Staff Nurse - 2015

Explanation

Plague is an infectious disease caused by the gram-negative bacterium Yersinia pestis.
It is a zoonotic disease, primarily affecting small mammals and their fleas. Humans typically get infected through the bite of an infected flea.
Y. pestis infection can manifest in several forms, including bubonic (most common), septicemic, and pneumonic plague.
Historically, Y. pestis was responsible for devastating pandemics, including the 'Black Death' in the 14th century.

Option A: Varicella-zoster is a virus, not a bacterium. It is responsible for causing chickenpox (varicella) in children and can reactivate later in life to cause shingles (herpes zoster).
Option B: Salmonella typhi is a bacterium that causes typhoid fever, a systemic illness typically spread through contaminated food or water. Its symptoms are different from plague.
Option D: The genus Corynebacterium includes the species Corynebacterium diphtheriae, which causes diphtheria, an acute bacterial infection of the throat and upper respiratory tract.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of Infectious Diseases as background academic context rather than a clinical decision trigger.
Nurses must be able to recognize the signs of plague (e.g., sudden onset of fever, chills, headache, and a painful, swollen lymph node or 'bubo') for prompt isolation and initiation of treatment.
Pneumonic plague is the most virulent form and can be spread from person-to-person. It requires strict droplet precautions (e.g., N95 respirator for staff, surgical mask on the patient) to prevent nosocomial and community spread.
Public health reporting is mandatory for suspected cases of plague. Nurses play a crucial role in notifying the appropriate authorities to initiate contact tracing and control measures.

How to Approach the Question

This is a factual recall question that tests your knowledge of microbiology and infectious diseases.
First, identify the key term in the question: 'plague'.
Next, systematically review each option, recalling the specific disease associated with each microorganism.
Option A, Varicella zoster, is a virus that causes chickenpox/shingles. Eliminate this option.
Option B, Salmonella typhi, is the bacterium that causes typhoid fever. Eliminate this option.
Option D, Corynebacterium, is the genus of bacteria that causes diphtheria. Eliminate this option.

Concept Tested & Keywords

QGThicC75807862gLdNtUa

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 pp. 1796-1798, 1798-1800

E6 Medicine Harrison 22e Part 1 p. 1383-1385

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.