Which virus causes chickenpox?

Appeared in: HP CHO -9 October 2022

Explanation

Chickenpox (varicella) is caused by the Varicella-zoster virus (VZV), which is also known as Human alphaherpesvirus 3.
Primary infection with VZV causes chickenpox, a highly contagious disease characterized by a vesicular rash.
After the initial infection, VZV remains latent in nerve ganglia and can reactivate later in life to cause herpes zoster (shingles).

Option A: The Pox virus family (Poxviridae) includes the Variola virus, which causes smallpox, a distinct and more severe disease than chickenpox.
Option B: RNA enteroviruses are a different group of viruses responsible for diseases like polio, hand-foot-and-mouth disease, and viral meningitis.
Option D: Clostridium tetani is a bacterium, not a virus. It produces a toxin that causes tetanus (lockjaw).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of Chickenpox as background academic context rather than a clinical decision trigger.
Recognizing chickenpox is crucial for implementing appropriate infection control measures (airborne and contact precautions) in a healthcare setting to prevent transmission to susceptible individuals, especially the immunocompromised and pregnant women.
Nurses play a key role in educating patients and parents about the VZV vaccine, which is highly effective in preventing chickenpox and its complications.
Understanding that VZV causes both chickenpox and shingles is important for patient assessment. A patient with a painful, dermatomal rash may have shingles, which requires prompt antiviral treatment to reduce pain and prevent postherpetic neuralgia.

How to Approach the Question

First, identify the core of the question, which is to name the specific causative agent for 'chickenpox'.
Scan the options. The question asks for a virus, so you can immediately be skeptical of any option that is not a virus (like a bacterium).
Recall or deduce the specific virus for chickenpox. Varicella is the medical term for chickenpox, which is a strong clue pointing towards 'Varicella-zoster virus'.
Evaluate the other options to confirm your choice. 'Pox virus' is a family, not a specific virus, and is associated with smallpox. 'RNA enterovirus' causes different diseases. 'Clostridium tetani' is a bacterium.
This process of elimination and direct recall confirms that Varicella-zoster virus is the correct answer.

Concept Tested & Keywords

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) p. 146-148

E6 Medicine Harrison 22e Part 1 pp. 1545-1547, 1090-1092

Practise the full HP CHO -9 October 2022

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