Table 1.

Chronological modifications to the definition of CE by national and international health organizations

Year	Organization	Cough etiquette developments and important events
1999	WHO [5,10,11]	Regarding problems with influenza pandemic vaccine production and availability, alternative control measures have to be thought of in advance.
2000	WHO [12]	Cough etiquette: Turning head and covering mouth when coughing, using clothes or spittoons to spit into.
2003		Severe acute respiratory syndrome
2005		Avian influenza
2006	ECDC [13]	Good respiratory hygiene: covering mouth and nose when coughing or sneezing using tissues and disposing them appropriately.
		NPI is an area neglected by research and those that fund research. There is little evidence and almost no experimental studies to show whether NPI measures work. This topic should receive urgent research attention.
	CPIP*[14]	Individuals with respiratory infection should be educated to cover their mouth and nose with a tissue when coughing and dispose of used tissues in waste containers.
	WHO [15]	Recommendations made for cough etiquette have been made more on the basis of plausible effectiveness than controlled studies.
2007	US-CDC [16]	The components of respiratory hygiene/cough etiquette are 1) covering the mouth and nose during coughing and sneezing, 2) using tissues to contain respiratory secretions with prompt disposal into a no-touch receptacle, 3) offering a surgical mask to persons who are coughing to decrease contamination of the surrounding environment, and 4) turning the head away from others and maintaining spatial separation, ideally >3 feet, when coughing.
		Effectiveness of currently recommended infection control measures for individuals is still unknown and additional research is needed to validate NPI and assess their effectiveness.
	CIDAAP**[17]	Respiratory hygiene/cough etiquette: Cover the nose/mouth when coughing or sneezing; cough or sneeze into elbow rather than hand.
2009		Influenza A H1N1 virus pandemic
	US-CDC [18]	Cover your mouth and nose with a tissue when coughing or sneezing; use the nearest waste receptacle to dispose of the tissue after use, perform hand hygiene.
	ECDC [19]	Cover your mouth and nose using tissues when coughing or sneezing; or cough or sneeze into an arm rather than your hands.
		There have never been trials of respiratory hygiene on either respiratory infections generally, or specifically influenza.
		Most European countries recommended to adopt the simple public health measures of: respiratory hygiene, hand washing, and early self-isolation.
2010	ECDC [19]	Personal protective measures (non-pharmaceutical) for reducing the risk of transmitting human influenza are based in part in evidence from studies and in part on judgment based on public health experience.

*Canadian pandemic influenza plan.

** Committee on infectious diseases of the American Academy of Pediatrics.