a-IPC cheat sheet

Chain of infection: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host; breaking any link prevents transmission.

Standard precautions apply to all patients regardless of diagnosis: hand hygiene, gloves, gown, mask/eye protection based on anticipated exposure to blood or body fluids.

Transmission-based precautions: contact (MRSA, C. difficile, scabies), droplet (influenza, pertussis, meningococcus), airborne (TB, measles, varicella) with N95 respirator and negative-pressure room.

Hand hygiene indications per WHO 5 Moments: before patient contact, before aseptic task, after body fluid exposure risk, after patient contact, after touching patient surroundings.

Alcohol-based hand rub is ineffective against C. difficile spores and norovirus; use soap and water for these organisms.

Droplet precautions require a surgical mask within about 3 feet (1 meter); airborne precautions require fit-tested N95 or higher and an airborne infection isolation room.

Sterilization destroys all microorganisms including spores; disinfection reduces or eliminates pathogens on inanimate objects but may not kill spores.

Personal protective equipment removal order: gloves first, then goggles/face shield, then gown, then mask/respirator last; perform hand hygiene after removal.

Post-exposure prophylaxis exists for HBV (vaccine and/or immune globulin), HIV (antiretroviral regimen), and varicella (VZIG or vaccine) but not for all pathogens.

Outbreak definition: increase in cases above the expected baseline for a defined population, place, and time; confirmed by comparing observed versus expected rates.

Attack rate = (number of new cases among exposed / number exposed) x 100; used in foodborne and point-source outbreak investigations.

Incidence measures new cases over a time period; prevalence measures all existing cases at a point in time (point prevalence) or over a period.

Device-associated infection rates are expressed per 1,000 device-days: (number of infections / number of device-days) x 1,000.

Surgical site infection rate = (number of SSIs / number of operative procedures) x 100, stratified by procedure and NNIS risk index.

Isolation duration rules: contact precautions for C. difficile typically until diarrhea resolves; MRSA contact precautions often continued until cultures negative per policy.

Occupational bloodborne exposure: wash the site with soap and water, do not squeeze or scrub, report immediately, and obtain source and exposed-person testing.

Notifiable disease reporting goes to the local or state public health authority within the jurisdiction's required timeframe (often 24 hours for urgent conditions).

Cleaning precedes disinfection; organic material inactivates many disinfectants, so visible soil must be removed before applying a disinfectant at the labeled contact time.