Which of the following is NOT considered a reservoir of infection?

• A. A contaminated water source
• B. An autoclave used to sterilize instruments
• C. Soil containing dormant bacterial spores
• D. An asymptomatic human carrier

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the concept of a 'reservoir of infection.' A reservoir of infection is any person, animal, plant, soil, or substance in which an infectious agent normally lives and multiplies, serving as a source from which other individuals can be infected.
2. Step 2: Analyze each option to determine if it can harbor and maintain the infectious agent over time, thus acting as a reservoir.
3. Step 3: Consider 'a contaminated water source' — water can harbor pathogens and serve as a reservoir, so this is typically considered a reservoir of infection.
4. Step 4: Consider 'soil containing dormant bacterial spores' — soil can contain spores of bacteria like Clostridium species, which can survive for long periods and infect hosts, so soil is a reservoir.
5. Step 5: Consider 'an asymptomatic human carrier' — such carriers harbor pathogens without showing symptoms and can transmit infection, making them reservoirs. Finally, consider 'an autoclave used to sterilize instruments' — since an autoclave is designed to kill all microorganisms, it does not serve as a reservoir of infection.