Droplet precautions

Droplets are particles of respiratory secretions ≥5 microns that remain suspended in the air for limited periods. Exposure within three to six feet (one to two meters) of the source can transmit the infection.

Droplet precautions are essential while caring for patients with suspected or confirmed infections with Neisseria meningitidis, Bordetella pertussis, influenza, parainfluenza, adenovirus, Haemophilus influenzae type b, Mycoplasma pneumoniae, rubella, COVID-19.

1. Respiratory viruses (such as parainfluenza virus and COVID-19) can be transmitted by contact and/or via droplets; both contact and droplet precautions should be implemented.
2. Respiratory syncytial virus (RSV) may be transmitted through droplets but is primarily spread by direct contact with infectious respiratory secretions. Therefore, the most important intervention for prevention of RSV transmission in healthcare settings is adherence to contact precautions (plus standard precautions).
3. The CDC does not recommend droplet precautions for RSV. However, droplet precautions are warranted if the infecting agent is not known, if the patient may be coinfected with other pathogens that require droplet precautions, and if exposure to aerosols of infectious respiratory secretions is probable.
4. Healthcare workers caring for patients on droplet precautions should wear a surgical mask when they are within six feet of patients.
5. No special air handling systems or higher-level respirator masks are required for the care of patients with known or suspected infection due to organisms capable of droplet transmission.
6. The doors of rooms used to house these patients may remain open (in contrast with airborne precautions).

 Contact precautions 

Contact precautions are needed for patients with select multidrug-resistant bacteria and several enteric and viral pathogens.

Patients requiring contact precautions should be kept in a private room or in a cohort with other patients having the same indication for contact precautions.

Certain respiratory viruses (such as parainfluenza virus) can be transmitted by contact and/or through droplets. Both contact and droplet precautions are thus required for patients with known or suspected infection due to such organisms.

Healthcare workers must perform hand hygiene and wear gloves on entering the room, even if no direct patient contact is anticipated. Gowns are a must even if direct contact with the patient or infective material is not likely.

Upon room exit, gowns and gloves should be removed and hand hygiene should be performed immediately as hands become contaminated during glove removal.

Medical equipment should be used for a single patient only when possible in order to avoid transfer of pathogens by means of fomites. Equipment not dedicated to a single patient ought to be cleaned and disinfected prior to reuse.

 Airborne precautions

Airborne droplet nuclei are particles of respiratory secretions <5 microns. Droplet nuclei can remain suspended in the air for extended period of time and thus can be a source of inhalational exposure for susceptible individuals.

Airborne precautions are warranted for the care of patients with suspected or confirmed tuberculosis, measles, varicella, smallpox, and severe acute respiratory syndrome (SARS).

Patients on airborne isolation precautions should be kept in a private room with negative air pressure with minimum  6 to 12 air changes per hour.

Doors to the isolation room must remain closed, and all individuals entering the room must wear a respirator with a filtering capacity of 95 percent that allows a tight seal over the nose and mouth.

In the setting of herpes zoster, airborne and contact precautions are warranted for all patients with disseminated zoster and for immunocompromised patients with localized zoster. Dtandard precautions may work for immunocompetent patients with localized zoster that can be contained/covered. Susceptible healthcare workers should refrain from providing direct care to these patients if immune caregivers are available.

COVID19 is transmitted predominantly by droplet spread and direct contact, although airborne transmission may also occur, especially during aerosol-generating procedures like endotracheal intubation; therefore, both airborne and contact precautions are warranted.

Patients in respiratory isolation who require transport outside their isolation rooms for medical procedures should wear surgical masks that cover the mouth and nose during transport. Procedures for these patients should be scheduled when they can be performed quickly and when occupation of waiting areas is minimal. [uptodate.com]

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA