title: Effectiveness of cough etiquette maneuvers in disrupting the chain of transmission of infectious respiratory diseases.
abstract: BACKGROUND
  The effectiveness of recommended measures, such as "cover your mouth when coughing", in disrupting the chain of transmission of infectious respiratory diseases (IRD) has been questioned. The objective of the current study was to determine the effectiveness of simple primary respiratory hygiene/cough etiquette maneuvers in blocking droplets expelled as aerosol during coughing.
  
  
  METHODS
  In this study, 31 healthy non-smokers performed cough etiquette maneuvers in an effort to cover their voluntarily elicited best effort coughs in an open bench format. A laser diffraction system was used to obtain accurate, non-invasive, quantitative, real time measurements of the size and number of droplets emitted during the assessed cough etiquette maneuvers.
  
  
  RESULTS
  Recommended cough etiquette maneuvers did not block the release and dispersion of a variety of different diameter droplets to the surrounding environment. Droplets smaller than one-micron size dominate the total number of droplets leaked when practicing assessed maneuvers.
  
  
  CONCLUSIONS
  All the assessed cough etiquette maneuvers, performed as recommended, do not block droplets expelled as aerosol when coughing. This aerosol can penetrate profound levels of the respiratory system. Practicing these assessed primary respiratory hygiene/cough etiquette maneuvers would still permit direct, indirect, and/or airborne transmission and spread of IRD, such as influenza and Tuberculosis. All the assessed cough etiquette maneuvers, as recommended, do not fully interrupt the chain of transmission of IRD. This knowledge urges us all to critically review recommended CE and to search for new evidence-based procedures that effectively disrupt the transmission of respiratory pathogens. Interrupting the chain of transmission of IRD will optimize the protection of first responders, paramedics, nurses, and doctors working in triage sites, emergency rooms, intensive care units, and the general public against cough-droplet-spread diseases.
authors.affiliation: Mucophysiology Laboratory, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada. g.zayas@ualberta.ca.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Zayas
authors.forename: Ming C
authors.initials: MC
authors.lastname: Chiang
authors.forename: Eric
authors.initials: E
authors.lastname: Wong
authors.forename: Fred
authors.initials: F
authors.lastname: MacDonald
authors.forename: Carlos F
authors.initials: CF
authors.lastname: Lange
authors.forename: Ambikaipakan
authors.initials: A
authors.lastname: Senthilselvan
authors.forename: Malcolm
authors.initials: M
authors.lastname: King
mesh_terms: D000328:Adult; D000336:Aerosols; D000416:Alberta; D003140:Communicable Disease Control / Q000379:methods*; D003371:Cough; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D006225:Hand / Q000382:microbiology; D006266:Health Education / Q000379:methods; D064368:Healthy Volunteers; D006801:Humans; D006920:Hygiene; D008297:Male; D008397:Masks / Q000382:microbiology; D008875:Middle Aged; D010316:Particle Size; D012141:Respiratory Tract Infections / Q000517:prevention & control* / Q000635:transmission; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D000336:Aerosols