Safety and Infection Control: Chain of Infection and Standard Precautions
Core concepts
Safety questions reward the habit of preventing harm before it happens. Learn the chain of infection: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host. Interventions break a specific link: hand hygiene breaks transmission; covering a cough limits exit; cleaning surfaces removes the reservoir; vaccination reduces host susceptibility.
Know Standard Precautions apply to every patient regardless of diagnosis: hand hygiene, gloves for contact with blood or body fluids, gown and mask when splash is likely, and safe sharps handling. Transmission-based precautions add to standard: contact (gown and gloves, e.g., C. difficile, MRSA), droplet (surgical mask, e.g., influenza, pertussis), airborne (N95 or higher, negative-pressure room, e.g., tuberculosis, measles). Alcohol-based rub is not effective against C. difficile spores; wash with soap and water. Never recap a needle with two hands; use the safety device or a one-handed scoop and dispose immediately in a sharps container.
Traps
Questions love the phrase "the patient has no known infection" to tempt you to skip gloves. Standard Precautions still apply. Another trap is choosing a mask when airborne isolation requires a fit-tested respirator. Watch for answers that reuse gloves between patients or place sharps in a regular trash can. For falls, remember: bed low, brakes locked, call light in reach, and round frequently.
Worked example
A patient with suspected tuberculosis is admitted. Rule of thumb: airborne precautions mean an N95 respirator plus a negative-pressure room, not just a surgical mask. Any answer offering only a surgical mask is wrong.
Rule of thumb
Ask which link of the chain an action breaks; if it does not clearly break one, it is probably not the best answer.