Table 4.

Contact definition by country and year

Country	Year	Definition for passengers	Definition for crew
Germany (air ambulance)	2012	Contact tracing of healthcare workers including those during transport to the hospital.	.
UK	2013	Two-row rule.	.
Italy	2013	Two-row rule.	All crew
Greece	2014	Two-row rule.	.
UK	2014	Two-seat radius around case prioritised, rest of passengers only tested and followed if they became symptomatic.	.
USA	2014	All passengers and crew (for all emerging diseases).	All crew
Netherlands	2014	Within three rows of case.	.
China	2014	Close contacts: two-row rule; other contacts: all other passengers.	.
Philippines	2015	Category A: passengers in surrounding three rows; category B: in surrounding three rows only transiting in Philippines; category E: all other passengers. (categories C and D were regarding contacts outside the flight).	.
China	2015	Close contacts: passengers in the adjacent two rows; other contacts: all other passengers on flight.	All crew
Thailand	2015	Passengers in the two rows surrounding case. Low risk: contact further than 1 m.	High risk: interaction closer than 1 m; low risk: contact further than 1 m
UK	2018	Three rows in front and behind.	.
South Korea	2018	Passengers sitting near case.	All crew