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Standard and transmission-based precautions: Clinical skills notes



Infection Control

Standard and Transmission-Based Precautions


When caring for a client, a set of protective practices should be applied to prevent the transmission of infection to and from the client. These include standard precautions, which are used for any client, at any time, in any situation; and transmission-based precautions, which are used for clients with a diagnosed or suspected infectious condition.

Standard precautions

Use personal protective equipment, or PPE, every time there's a risk for exposure to:
  • blood
  • all types of body fluids, secretions, and excretions other than sweat
  • open skin lesions or rashes
  • mucosal surfaces
  • possibly contaminated items or surfaces

This includes wearing gloves; a waterproof gown if there’s a possibility that your clothes get contaminated; and protective mask, goggles, or a face shield for procedures where splashes of body fluids are likely.

Figure 1: Personal protective equipment (PPE).

When moving from a contaminated area to a clean body area, remember to change your gloves and wash your hands thoroughly. Do the same after touching any surfaces in or out of the care setting.

  • If there’s no access to water or soap and your hands aren’t visibly dirty, you can also use an alcohol-based sanitizer. Remember to still wash your hands afterwards as soon as you can. 

In the case of unexpected contact with blood or any body fluids: 

  1. Wipe up any spills.
  2. Disinfect the area with a facility-approved cleaning product.
  3. Practice hand hygiene right away.

In any case, before leaving the client’s room or moving on to another client, remove all your personal protective equipment and practice hand hygiene.

To limit the potential transmission of respiratory infections, standard precautions include: 

  • wearing a mask when caring for clients with suspicious signs or symptoms, like cough
  • instructing these clients to keep at least a one meter, or three feet, distance between themselves and others or to otherwise wear a mask
  • instructing clients to cover their nose and mouth with a tissue whenever they sneeze or cough, and then immediately throw the tissue away in the nearest wastebasket and wash their hands

It might also be helpful to hang a visual reminder of the instructions next to the client’s bed to inform potential visitors.

Transmission-based precautions

Transmission-based precautions are categorized based on the route of transmission of the infectious agent. 

Airborne precautions

  • Refer to clients infected with pathogens transmitted via the airborne route.
    • This means that they can survive and travel through the air over long distances and for an extended period of time, usually several hours to days.
  • These pathogens include:
    • Mycobacterium tuberculosis
    • measles
    • varicella virus (chicken pox)
    • possibly SARS-CoV-2, or severe acute respiratory syndrome coronavirus 2, which is the virus that causes COVID-19
  • In all these cases, the client should be isolated in an airborne infection isolation room, otherwise known as a negative pressure room, with the door closed. These rooms have a ventilation system that allows air to flow in but not out of the room to prevent cross-contamination between rooms. Then, before this air gets released in the outside environment, it passes through a special barrier called a HEPA filter to completely remove all the pathogens.
  • Before entering an airborne precaution isolation room, make sure to put on a fit-tested high-filtration respirator.
  • If possible, all procedures should be carried out in this room. But if it's absolutely necessary to transport the client, they should wear a surgical mask.

Figure 2: Airborne infection isolation room.

Droplet precautions

  • Taken when caring for a client with an infectious condition transmitted via droplets.
    • This means every time the client talks, coughs, or sneezes, loads of tiny droplets containing the pathogen are sprayed out. These droplets can land on another person’s mouth, nose, or eyes, allowing the pathogen to enter a new person.
  • Some examples of these pathogens include:
    • mumps
    • rubella and influenza virus
    • diphtheria
    • Streptococcus
    • pertussis
  • Droplet precautions are similar to airborne ones, with the exception that you only need to apply a face shield and simple face mask when you are closer than one meter, or three feet, to the client.

Contact precautions

  • Used for clients with infections that are transmitted by either direct contact, which is touching the infected client; or indirect contact, which is touching a surface, like a contaminated doorknob, and then touching your own eyes, nose, or mouth.
  • Such pathogens include:
    • staphylococcus aureus
    • herpes simplex
    • varicella zoster
    • respiratory syncytial virus (RSV)
    • SARS-CoV-2, which causes COVID-19
  • For all interactions with these clients or their environment, make sure to always wear gloves and gown and handle and discard contaminated items, like linens, in the appropriate way.

Enteric precautions

  • Help limit the spread of gastrointestinal pathogens, like Clostridium difficile, which are transmitted by the fecal oral route, as well as by direct and indirect contact.
  • Similar to contact precautions, but special attention should be paid to safe disposal or the client's excretions.
    • If bedpans or urinals are used, these have to be carefully discarded into the toilet, rinsed, and disinfected.
  • Toilet seats, sinks, and door handles should be cleaned frequently.
  • These clients should also be reminded to always wash their hands thoroughly after defecation and urination.

Reverse isolation

All the precautions described above aim to prevent an infected client from transmitting their disease to others. Reverse isolation, on the other hand, is used to protect a vulnerable client from contracting infection. This is important for clients whose immune system’s ability to fight infections is compromised, because they can suffer severe complications if exposed to infectious agents. Examples include clients undergoing chemotherapy or those with leukemia. 

  • These clients are usually kept in a private room with an air ventilation system. 

  • Before someone enters the room, they need to practice hand hygiene and put on a mask, gloves, and a gown. 

  • Visitors are limited and gifts of any kind or plants are not allowed in the room. 

  • Personal items and medical equipment should not be shared.

Double-bagging procedure

When contaminated items need to be carried out of a client’s room, two healthcare workers are required. This procedure is also known as double-bagging

  1. The first healthcare worker, known as the “contaminated” one, goes into the client’s room, takes the contaminated items, carefully positions them in an isolation bag, and ties the ends of the bag to secure it. 

  2. The second one, called the “clean” healthcare worker, remains outside of the client’s room holding a second plastic bag. To protect their hands, they form a cuff or collar by folding the top of the bag around their hands. 

  3. The “contaminated” healthcare worker steps outside the client’s room and places the first bag into the second one. 

  4. The “clean” healthcare worker then seals the second bag carefully, touching only the outside of the bag, and proceeds to discard it in a facility-approved manner. 

  5. Both healthcare workers remove their gloves and practice hand hygiene.

Figure 3: Double-bagging procedure. A. The "contaminated" healthcare worker goes into the clients room, and B. hands the contaminated items to a "clean" healthcare worker.