Role of viral bioaerosols in nosocomial infections and measures for prevention and control

Abstract

A B S T R A C TThe presence of patients with diverse pathologies in hospitals results in an environment that can be rich in various microorganisms including respiratory and enteric viruses, leading to outbreaks in hospitals or spillover infections to the community. All hospital patients are at risk of nosocomial viral infections, but vulnerable groups such as older adults, children and immuno-compromised/-suppressed patients are at particular risk of severe outcomes including prolonged hospitalization or death. These pathogens could transmit through direct or indirect physical contact, droplets or aerosols, with increasing evidence suggesting the importance of aerosol transmission in nosocomial infections of respiratory and enteric viruses. Factors affecting the propensity to transmit and the severity of disease transmitted via the aerosol route include the biological characteristics affecting infectivity of the viruses and susceptibility of the host, the physical properties of aerosol particles, and the environmental stresses that alter these properties such as temperature and humidity. Non-specific systematic and individual-based interventions designed to mitigate the aerosol route are available although empirical evidence of their effectiveness in controlling transmission of respiratory and enteric viruses in healthcare settings are sparse. The relative importance of aerosol transmission in healthcare setting is still an on-going debate, with particular challenge being the recovery of infectious viral bioaerosols from real-life settings and the difficulty in delineating transmission events that may also be a result of other modes of transmission. For the prevention and control of nosocomial infections via the aerosol route, more research is needed on identifying settings, medical procedures or equipment that may be associated with an increased risk of aerosol transmission, including defining which procedures are aerosol-generating; and on the effectiveness of systematic interventions on aerosol transmission of respiratory and enteric viruses in healthcare settings.

Cold atmospheric plasma inactivation of aerosolized microdroplets containing bacteria and purified SARS‐CoV‐2 RNA to contrast airborne indoor transmission

“…In this perspective, new preventive solutions to mitigate the effects of airborne transmission might be needed, including suitably modified ventilation systems in synergy with powerful new filtering devices able to capture and/or inactivate the airborne microdroplets. [ 6,8–12 ] Indeed, several studies demonstrated that the transmission via aerosols is of great importance in the COVID‐19 pandemic caused by the SARS‐CoV‐2. [ 9 ] In particular, the SARS‐CoV‐2 virus is primarily released from the respiratory tract as an aerosol with droplets generated, for example, by exhalation, talking, sneezing, coughing, and it can be increasingly released through intubation, bronchoscopy, rhinoscopy, or surgical interventions.…”

“…In this perspective, new control technologies capable of inactivating aerosolized bacteria and viruses are highly sought after; these new technologies must be economically convenient, should not be responsible for secondary pollution, and must be able to effectively inactivate different types of pathogens. [ 8,17 ] However, the efficacy of treatments depends on genome structure of the pathogens and their replication machinery [ 18 ] ; furthermore, new technologies must take into account the possibility that both bacteria and viruses could develop harmful mutagenic outcomes associated with multiple transition mutations across the genome when they are underexposed or undergo insufficient inactivation treatments. [ 18,19 ]…”

Reducing Aerosol-Related Risk of Transmission in the Era of COVID-19: An Interim Guidance Endorsed by the International Society of Aerosols in Medicine

“…(16) Nevertheless, HCWs should learn how to reduce risks associated with all aerosol delivery devices as not all drugs that are nebulized in the acute care setting are available in pMDIs, dry powder inhalers (DPIs), or soft mist inhalers (SMIs) such as antibiotics and prostaglandins. (17,18) Inhalers, such as pMDIs, have been suggested to present less risk than other medical aerosols, often without supporting evidence. (19,20) The rationale for reduced risk compared with other medical aerosols may be because drug is enclosed and less open to contamination than open cup nebulizers, and the low emitted dose (100 lL/actuation) produces less aerosol mass with shorter treatment times.…”

The Need for Ocular Protection for Health Care Workers During SARS-CoV-2 Outbreak and a Hypothesis for a Potential Personal Protective Equipment

“…For example, during the slit lamp or direct fundoscopy examination, an ophthalmology doctor need to directly face the patient at a distance of 3-10 cm. There is also huge risk of aerosol exposure during processes such as dental repair, open surgery, tracheal intubation and so on (51,52). A recent survey conducted in British ophthalmology practitioners showed that they were very unconfident about no ocular protection in the daily work and called for more eye protection (53).…”