The 32-year-old American, who is under the first U.S. government-ordered quarantine since 1963, flew from Atlanta to Paris in early May to celebrate his wedding and honeymoon in Europe and returned from Prague by way of Montreal, each time taking regular trans-Atlantic flights.
The decision was taken at the recommendation of the European Center for Disease Prevention and Control (ECDC) and concerns people who were in close proximity to the American, who has a highly drug-resistant form of tuberculosis (XDR-TB), on board the flights.
"As a precautionary measure and following recommendations from the World Health Organization (WHO), the ECDC's advice is to perform contact tracing for passengers 2 rows ahead, 2 rows behind and the row of the infected passenger, and the cabin crew concerned," the ECDC said in a statement. "The ECDC's advice is that the risk for these persons is very limited, other passengers are not considered at risk."