American Board of Internal Medicine (ABIM) Certification Practice Exam

What is a common source of exposure leading to infections by Pasteurella multocida?

1. Veterinary clinics

2. Contact with infected animals or animal products

3. Food and water contamination

4. Hiking in wooded areas

The correct answer is: Contact with infected animals or animal products

The identification of contact with infected animals or animal products as a common source of exposure leading to infections by Pasteurella multocida is grounded in the bacterium's ecology and transmission pathways. Pasteurella multocida is primarily found in the oral and nasopharyngeal regions of various animals, particularly domestic pets like cats and dogs, as well as livestock. Infections in humans often occur following bites, scratches, or licks from these animals, as well as through handling infected animal tissues or products. The transmission of Pasteurella multocida through direct contact with infected animals is well-documented, particularly in cases involving pet owners or veterinary personnel who may experience injuries while handling animals. This highlights the importance of understanding the zoonotic nature of certain pathogens, where animals can serve as reservoirs that transmit infections to humans. While veterinary clinics might be a setting where such exposure occurs, the broader context of general contact with infected animals and their products encapsulates the primary mode of infection more comprehensively. Additionally, food and water contamination and hiking in wooded areas are less relevant sources for Pasteurella multocida specifically, as these pathways are not associated with the usual transmission mechanisms for this bacterium.