The first human disease that was proved to have a viral etiology is?

UPRVUNL - 2021

Applied Microbiology & Infection control

Easy

Appeared in: UPRVUNL - 2021

Explanation

Yellow fever was the first human disease proven to have a viral etiology.
In 1901, the Walter Reed Commission in Cuba demonstrated that the disease was caused by a filterable agent (a virus).
This commission also confirmed that the virus was transmitted by the Aedes aegypti mosquito, a discovery initially proposed by Cuban scientist Carlos Finlay.
This finding was a cornerstone in the history of medicine, establishing the concept of viruses as disease-causing agents in humans and the role of vectors in transmission.

Option B: Although a vaccine for smallpox was developed by Edward Jenner in 1796, this was based on observation and predated the discovery of viruses. The viral cause of smallpox was not proven until much later.
Option C: Louis Pasteur developed a vaccine for rabies in 1885. However, like with smallpox, this was achieved without the understanding that a virus was the causative agent. The viral nature of rabies was confirmed later.
Option D: The various viruses that cause hepatitis (A, B, C, D, E) were discovered much later in the 20th century. For example, the Hepatitis B virus was visualized in 1970, and the Hepatitis A virus was identified in 1973.

Clinical Relevance

Nursing practice connection: Knowing History of Virology helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding the history of virology helps appreciate the scientific foundation of modern infectious disease control, including vaccination, vector control, and antiviral therapies.
The discovery that yellow fever was transmitted by mosquitoes directly led to public health strategies focused on vector control (e.g., eliminating mosquito breeding sites), which remain critical for preventing many diseases today (like Dengue, Zika, and Chikungunya).
What if the question asked for the first virus ever discovered? The answer would be Tobacco Mosaic Virus (TMV), which was identified as a 'filterable agent' infecting tobacco plants in 1892 by Dmitri Ivanovsky, predating the discovery of the first human virus.

How to Approach the Question

First, identify the key terms in the question: 'first human disease', 'proved', and 'viral etiology'.
The word 'proved' is crucial. It means you are looking for the first time a scientific link was definitively established between a virus and a human illness.
Consider each option in a historical context. You may know that vaccines for smallpox and rabies existed early on.
Differentiate between the development of a vaccine (which can be done without knowing the exact cause) and the scientific proof of the causative agent.
Recall or deduce that the concept and proof of viruses came after the initial work on vaccines for smallpox and rabies.
Evaluate Yellow Fever and Hepatitis. Yellow Fever's discovery in the early 1900s places it as a foundational event in virology, whereas hepatitis viruses were identified much more recently. This makes Yellow Fever the most likely correct answer.

Concept Tested & Keywords

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E6 Medicine Davidson Principles Practice 24e p. 265-267