Mukherjee P, Lim PL, Chow A, Barkham T, Seow E, Win MK, Chua A, Leo YS, Cheng Chen MI
Emerg Infect Dis.2010 Jan;16(1):21-6
Description: In June 2009, during Singapore's pandemic influenza plan containment phase, pandemic (H1N1) 2009 was introduced into the country through imported cases. To understand how travel patterns affected the initial outbreak, the authors examined epidemiological and travel data for the first 116 case-patients admitted with travel-associated infection to Tan Tock Seng Hospital, Singapore,. 61% and 54% of patients, respectively, met US Centers for Disease Control and Prevention and World Health Organization temperature criteria for influenza-like illness. One fourth of the case-patients travelled after illness onset, and 15% became ill while travelling. Regions of exposure for imported infections changed rapidly; case-patients initially arrived from North America, followed by Australasia and Southeast Asia. Case-patients on longer flights were more likely to become ill before arrival; those with shorter flights tended to become ill after arrival. Thermal scanners detected fevers in 12% of the arriving case-patients, resulting in a shorter time to isolation.
Link to the article
ECDC comment: 2010-02-01: Data from the authors shows that only a minority of cases were detected by airport thermal scanners. These measures are not considered effective for early detection and containment, as passengers have to become symptomatic before disembarking from a flight and have fever high enough to be detected, so prevention efforts should focus on other strategies. However, detection does result in a hospital referral by an airport doctor leading to shorter time to isolation and treatment, and may build confidence among some travellers.