The Airborne Transmission of Infection in Hospital Buildings: Fact or Fiction?

Abstract

Airborne transmission is known to be the route of infection for diseases such as tuberculosis and aspergillosis. It has also been implicated in nosocomial outbreaks of MRSA, Acinetobacter spp. and Pseudomonas spp. Despite this there is much scepticism about the role that airborne transmission plays in nosocomial outbreaks. This paper investigates the airborne spread of infection in hospital buildings, and evaluates the extent to which it is a problem. It is concluded that although contact-spread is the principle route of transmission for most infections, the contribution of airborne micro-organisms to the spread of infection is likely to be greater than is currently recognised. This is partly because many airborne micro-organisms remain viable while being non-culturable, with the result that they are not detected, and also because some infections arising from contact transmission involve the airborne transportation of micro-organisms onto inanimate surfaces.

Dispersion of Expiratory Droplets in a General Hospital Ward with Ceiling Mixing Type Mechanical Ventilation System

“…Among various routes of transmission the significance of airborne transmission in nosocomial infections remains skeptical in the medical society, as suggested by Beggs (2003). The skepticisms come from the lack of knowledge in how airborne microorganisms are dispersed in air and mis-understandings in their viability in air.…”

“…Diseases identified as "Airborne" transmittable, such as tuberculosis (TB), require air isolation. Such classification remains questionable by physical scientists and engineers as reviewed by Beggs (2003). Some droplets of >5 μm in size had evaporation time scales much shorter than their settling time scales, making them become droplet DISPERSION OF EXPIRATORY DROPLETS 245 nuclei before getting settled.…”

Decontamination of the Hospital Environment: New Technologies for Infection Control

“…Microbiological contamination of the clinical environment is increasingly being highlighted as a source of infection, with direct contact with contaminated surfaces, indirect contact with contaminated surfaces via the hands of medical staff or equipment, and the air, all being recognised as potential sources of cross-infection [1][2][3]. High standards of cleaning and disinfection will contribute to minimising the risk of infection, and have been shown to play an important role in controlling outbreaks of infection [4,5].…”

Army Transformation: A Cultural Change

“…Thousands of droplets 1~10 μm in diameter containing viable microorganisms released by a person will quickly contract by evaporation to form droplet nuclei, which remain suspended in air for long periods of time and travel considerable distances as or by attaching to aerosols. In particular, respiratory viruses appear to be spread mainly by droplet nuclei [7,8]. Due to droplet encasement, virus infectivity can be shielded from external forces (e.g., drying, sunlight, and temperature) [9].…”