The virus that causes smallpox (Variola) is -

Appeared in: Raj. CHO - 2023

Explanation

The question provides a direct clue by equating the common name of the disease, smallpox, with its scientific name, Variola.
The Variola virus, a member of the Orthopoxvirus family, is the specific causative agent for the infectious disease known as smallpox.
Smallpox was a highly contagious and often fatal disease before its global eradication through a successful vaccination program.
The name of the virus and the disease it causes are eponymous in this case, making 'Variola' the correct choice.

Option A: Varicella refers to the Varicella-zoster virus (VZV), which is a type of herpesvirus.
Option B: Rubella is the virus that causes German measles, a different viral exanthem.
Option C: Influenza viruses are responsible for the seasonal flu, which is primarily a respiratory illness and does not typically cause a vesicular rash like smallpox.

Visual 1: Diagram - A side-by-side comparison of the rash distribution in smallpox (centrifugal) and chickenpox (centripetal). This helps visualize a key diagnostic difference.
Visual 2: Infographic - A timeline showing the key milestones of the WHO's smallpox eradication program, culminating in 1980. This highlights one of public health's greatest achievements.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Causative agent of smallpox as background academic context rather than a clinical decision trigger.
Despite its eradication, knowledge of smallpox is critical for biopreparedness, as the virus could be used as a bioterrorism agent. Nurses must be aware of the classic signs to aid in early detection.
The global eradication of smallpox is a prime example of the effectiveness of vaccination campaigns. The vaccine used a live, related virus called vaccinia to confer immunity.
What if? If a patient presented with a widespread vesicular rash and fever, a nurse's priority assessment would be to determine if the lesions are all in the same stage (synchronous, suggesting smallpox) or in different stages (asynchronous, suggesting chickenpox). This finding would be critical to report immediately.

How to Approach the Question

First, carefully read the question stem and identify the key terms: 'virus', 'smallpox', and the parenthetical '(Variola)'.
Recognize that the question itself provides the scientific name for the smallpox virus, which is 'Variola'. This is a significant clue.
Scan the provided options to see if this name is listed.
Option D, 'Variola', is an exact match to the name given in the question.
To confirm, mentally review the other options. 'Varicella' is chickenpox, 'Rubella' is German measles, and 'Influenza' is the flu. Since these are all incorrect, it solidifies 'Variola' as the right answer.

Concept Tested & Keywords

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E6 Microbiology Applied AnjuDhir 3e Part 1 p. 367-368

Practise the full Raj. CHO - 2023

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