The following answer choices list a disease followed by the primary organism(s) that carries that disease. Which of the following is not an example of a zoonotic disease?

• A. Measles virus; humans.
• B. Rabies virus; all mammal species.
• C. Yersinia pestis (plague); rodents and fleas.
• D. West Nile virus; birds and mosquitos. 

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the definition of a zoonotic disease. A zoonotic disease is an infectious disease that can be transmitted from animals to humans.
2. Step 2: Review each disease and its primary organism(s) to determine if the disease is transmitted from animals to humans (zoonotic) or only between humans.
3. Step 3: Analyze 'Measles virus; humans.' Measles is a viral disease that is transmitted only between humans, with no animal reservoir involved, so it is not zoonotic.
4. Step 4: Analyze 'Rabies virus; all mammal species.' Rabies is transmitted from infected mammals to humans, making it a classic example of a zoonotic disease.
5. Step 5: Analyze 'Yersinia pestis (plague); rodents and fleas' and 'West Nile virus; birds and mosquitos.' Both involve animal reservoirs and vectors transmitting the disease to humans, confirming their zoonotic nature.