In the chain of infection, which link is most directly interrupted by standard precautions (e.g., hand hygiene, gloves, gowns, masks)?

• A. Mode of transmission
• B. Susceptible host
• C. Portal of exit
• D. Infectious agent

Answer: (A)

Verified step by step guidance

1. Understand the chain of infection, which consists of six links: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host.
2. Identify what standard precautions are: these include hand hygiene, use of gloves, gowns, masks, and other protective measures designed to prevent the spread of pathogens.
3. Analyze how standard precautions work: they primarily aim to block the ways pathogens move from one host or environment to another, especially by interrupting direct or indirect contact.
4. Recognize that by practicing hand hygiene and using protective barriers, the transmission of infectious agents from one person or surface to another is prevented, effectively breaking the 'mode of transmission' link.
5. Conclude that while other links like the infectious agent or susceptible host are important, standard precautions most directly interrupt the mode of transmission in the chain of infection.