Transmission-based precautions (TBPs) are used in addition to Standard Precautions when they alone may be insufficient to prevent the transmission of infections (Health Victoria, 2020). TBPs are used for patients known or suspected to be infected or colonised with epidemiologically important or highly transmissible pathogens that can transmit or cause infection (CDC, 2016). The type of TBPs applied is based upon the mode of transmission of the pathogen and for diseases that have multiple routes of transmission, more than one TBP category is applied. There are three main routes of transmission to consider: contact, droplet and airborne.
Precautions for Contact transmission are required for patients known or suspected to be infected or colonised with microorganisms that can be transmitted by:
- direct contact e.g. contact when performing patient-care activities that require touching the patient’s skin or bodily fluid secretions; or;
- indirect contact e.g. touching potentially contaminated environmental surfaces or equipment in the patient’s environment (CDC, 2016).
Examples include Staphylococcus aureus (MSSA or MRSA), Vancomycin-resistant enterococci (VRE), Clostridium difficile infection (CDI) and scabies.
Precautions for Droplet transmission are required for patients known or suspected to be infected with microorganisms transmitted by droplets. Droplets can be generated by coughing, sneezing, talking or during the performance of procedures (e.g. nebulisation) (CDC, 2016).
Examples include pertussis, influenza, rubella, and mumps.
Precautions for Airborne transmission are required for patients known or suspected to be infected with microorganisms that can be transmitted to other patients/staff via the airborne route (CDC, 2016)
Examples include Tuberculosis, chickenpox, and measles.
Note: Some diseases have multiple routes of transmission and more than one transmission-based precautions category may be used, for example, Multi-drug resistant microorganisms such as Multi-drug resistant tuberculosis (MDR-TB) and Human respiratory syncytial virus (RSV). When used either singularly or in combination, they are always used in addition to Standard Precautions.
Transmission based precaution requirements (Siegel et al., 2007; CDC 2016)
Contact Precautions
- Ensure appropriate patient placement
- In acute care hospitals: use a single patient space or room if available.
- In long-term and other residential settings: make room placement decisions by balancing risks to other patients. Place together patients in the same room who are infected or colonised with the same pathogen.
- In ambulatory settings: place patients in an exam room or cubicle as soon as possible.
- Use personal protective equipment (PPE) appropriately, including gloves and gown.
- Wear a gown and gloves for all interactions that may involve contact with the patient or the patient’s environment.
- Donning PPE upon room entry and properly discarding before exiting the patient room is done to contain pathogens.
- Limit transport and movement of patients outside of the room to medically-necessary purposes.
- When transport or movement is necessary, cover or contain the infected or colonized areas of the patient’s body.
- Remove and dispose of contaminated PPE and perform hand hygiene prior to transporting patients on Contact Precautions.
- Don clean PPE to handle the patient at the transport location.
- Use disposable or dedicated patient-care equipment (e.g., blood pressure cuffs).
- If common use of equipment for multiple patients is unavoidable, clean and disinfect such equipment before use on another patient.
- Prioritise cleaning and disinfection of patient rooms
- Ensure rooms are frequently cleaned and disinfected at least daily or prior to use by another patient if the outpatient setting,
- Focus on frequently-touched surfaces and equipment in the immediate vicinity of the patient (e.g., bed rails, overbed table, bedside commode, lavatory surfaces in patient bathrooms, doorknobs).
Droplet Precautions
- Ensure appropriate patient placement in a single room if possible.
- In acute care hospitals: if single rooms are not available, prioritise patients who have excessive coughing and sputum production for single-patient room placement. Place patients in the same room who are infected with the same pathogen.
- In long-term care and other residential settings: make decisions regarding patient placement on a case-by-case basis considering infection risks to other patients in the room and available alternatives.
- In ambulatory settings: place patients who require Droplet Precautions in an exam room or cubicle as soon as possible and instruct patients to follow Respiratory Hygiene/Cough Etiquette.
- Use personal protective equipment (PPE) appropriately.
- Don mask upon entry into the patient room or patient space.
- Limit transport and movement of patients outside of the room
- If transport or movement outside of the room is necessary, instruct the patient to wear a mask and follow Respiratory Hygiene/Cough Etiquette.
Airborne Precautions
- Ensure appropriate patient placement in an airborne infection isolation room (AIIR) constructed according to the Guideline for Isolation Precautions.
- In settings where Airborne Precautions cannot be implemented due to limited engineering resources, masking the patient and placing the patient in a private room with the door closed will reduce the likelihood of airborne transmission until the patient is either transferred to a facility with an airborne infection isolation room (AIIR) or returned home.
- Restrict susceptible healthcare personnel from entering the patient’s room
- Patients known or suspected to have measles, chickenpox, disseminated zoster, or smallpox should be cared for by immune healthcare personnel if available.
- Use personal protective equipment (PPE) appropriately, including a fit-tested NIOSH-approved N95 or higher-level respirator for healthcare personnel.
- Limit transport and movement of patients outside of the room
- If transport or movement outside an AIIR is necessary, instruct patients to wear a surgical mask, if possible, and observe Respiratory Hygiene/Cough Etiquette.
- Healthcare personnel transporting patients who are on Airborne Precautions do not need to wear a mask or respirator during transport if the patient is wearing a mask and infectious skin lesions are covered.
- Immunise susceptible persons as soon as possible following unprotected contact with vaccine-preventable infections (e.g., measles, varicella, or smallpox).
- Administer measles vaccine to exposed susceptible persons within 72 hours after the exposure. (CDC, 2019)
- Administer varicella vaccine to exposed susceptible persons within 120 hours after the exposure. (CDC, 1969)
- Administer smallpox vaccine to exposed susceptible persons within 4 days after exposure. (Petersen et al., 2015)
- Environmental Controls
- Filter incoming air using central or point-of-use high-efficiency particulate (HEPA) filters capable of removing 99.97% of particles ≥0.3 µm in diameter (CDC, 2020).
- Monitor air pressure daily with visual indicators (e.g., smoke tubes, flutter strips)
- Ensure well-sealed rooms that prevent infiltration of outside air (CDC, 2020).
- Avoid carpeting in hallways and patient rooms in areas (CDC, 2020).
Table 1: Transmission-based precautions required according to the route of transmission
| Infection control measures | Route of Transmission | ||
| Contact | Droplet | Airborne | |
| Gloves | For all manual contact with patients, environmental surfaces, and hospital devices | As per standard precautions | As per standard precautions |
| Aprons/Gowns | Yes | As per standard precautions | As per standard precautions |
| Respirators | Not required | Not required | Yes (P2 or N95) |
| Masks | As per standard precautions | Yes | No |
| Goggles/Shields | As per standard precautions | Yes | As per standard precautions |
| Patient Placement | Yes or cohort patients with the same infection | Yes or cohort patients with same infection (door closed) | No |
| Negative Pressure Ventilation Rooms | Not required | Not required | Essential |
| Door/ Bed Signs | Isolation notice should be displayed Advice all staff of the necessary precautions | Isolation notice should be displayed Advice all staff of the necessary precautions | Isolation notice should be displayed Advice all staff of the necessary precautions |
| Visits to another department | Limit movement of a patient from the room to essential purposes only If transfer/ movement is necessary, notify the receiving department/IPC | Limit movement of a patient from the room to essential purposes only If transfer/ movement is necessary, place a surgical fluid shield mask on the patient If transfer/movement is necessary, notify the receiving department/IPC Team in advance | Limit movement of a patient from the room to essential purposes only If transfer/ movement is necessary, place a surgical fluid shield mask on the patient If transfer/movement is necessary, notify the receiving department/IPC Team in advance |
| Cutlery/Crockery | Separate or disposable cutlery or crockery is not indicated | Separate or disposable cutlery or crockery is not indicated | Separate or disposable cutlery or crockery is not indicated |
Source: CDC 2017; Health Victoria, 2020
Signage
Signage should be positioned prominently outside the room of a patient in TBPs. This is to ensure staff and visitors do not enter without appropriate PPE. The following are examples of signs for Contact, Droplet, and Airborne Precautions that can be posted outside patient rooms.
References
CDC. 2020. Guideline For Isolation Precautions: Preventing Transmission Of Infectious Agents In Healthcare Settings (2007). [online] Available at: <https://www.cdc.gov/infectioncontrol/guidelines/isolation/precautions.html> [Accessed 9 November 2020].
CDC. 2019. Interim Measles Infection Prevention Recommendations In Healthcare Settings | CDC. [online] Available at: <https://www.cdc.gov/infectioncontrol/guidelines/measles/index.html> [Accessed 9 November 2020].
CDC 2016. Transmission-Based Precautions | Basics | Infection Control | CDC”. [online] Available at: <https://www.cdc.gov/infectioncontrol/basics/transmission-based-precautions.html> [Accessed 9 November 2020].
CDC, 1969. Prevention Of Varicella: Recommendations Of The Advisory Committee On Immunization Practices (ACIP). Morbidity and Mortality Weekly Report (MMWR) July 12, 1996, / 45(RR11);1-25. [online] CDC. Available at: <https://www.cdc.gov/mmwr/preview/mmwrhtml/00042990.htm> [Accessed 9 November 2020].
Health Victoria. 2020. Infection Control – Standard And Transmission-Based Precautions. [online] Available at: <https://www2.health.vic.gov.au/public-health/infectious-diseases/infection-control-guidelines/standard-additional-precautions#:~:text=Transmission%2Dbased%20precautions%20are%20used,spread%20of%20an%20infectious%20agent.&text=Transmission%2Dbased%20precautions%20are%20based,transmission%20of%20the%20infectious%20agent.> [Accessed 9 November 2020].
Petersen, B., Damon, I., Petrowski, C., Delman, D., Guarnizo, J., H. Beigi, R., Edwards, K. and Fisher, M., 2015. Clinical Guidance For Smallpox Vaccine Use In A Postevent Vaccination Program. Morbidity and Mortality Weekly Report (MMWR) 64(RR02);1-26. [online] CDC. Available at: <https://www.cdc.gov/mmwr/preview/mmwrhtml/rr6402a1.htm> [Accessed 9 November 2020].
Siegel, J., Rhinehart, E., Jackson, M. and Chiarello, L., 2007. 2007 Guideline For Isolation Precautions: Preventing Transmission Of Infectious Agents In Healthcare Settings. 2nd ed. [ebook] Healthcare Infection Control Practices Advisory Committee (HICPAC), pp.43-64. Available at: <https://www.cdc.gov/infectioncontrol/pdf/guidelines/isolation-guidelines-H.pdf> [Accessed 9 November 2020].
National Health and Medical Research Council 2010. Australian guidelines for the prevention and control of infection in healthcare. Canberra Available at:< https://www.safetyandquality.gov.au/standards/nsqhs-standards/preventing-and-controlling-healthcare-associated-infection-standard/infection-prevention-and-control-systems> (accessed Sep 2017).
