BMJ 2014;349:g6571 doi: 10.1136/bmj.g6571 (Published 4 November 2014)
Page 1 of 1
Letters
LETTERS AIRPORT SCREENING FOR EBOLA
Airport screening for Ebola: current thermal scanning procedures are unreliable 1
1
Cyrus Rustam Kumana emeritus professor , Bernard M Y Cheung professor , Lung S Chan 2 professor Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong; 2Department of Earth Sciences, University of Hong Kong, Hong Kong 1
We agree with the editorial on airport screening for Ebola virus,1 which challenges the policy of enhanced screening as currently used. Whether applied to those exiting an affected area or arrivals, apart from being easily circumvented, temperature checks that depend on currently deployed thermal scanning procedures in common use are unreliable. When using remote sensing infrared thermography, the most reliable estimate of body temperature is obtained when the probe is targeted at the ear and not the forehead or face; the most accurate reading accrues if the camera points to the side of the face and is at a short distance (about 1 m) from the hotspot in the ear. These findings stemmed from research carried out in Hong Kong during and after the epidemic of severe acute respiratory syndrome.2 3 It is hardly surprising therefore that a healthcare worker arriving in New York after caring for patients with Ebola has complained about her detention and quarantine based on readings from a
forehead scanner and a confusing array of other findings. This account was first published in the Dallas Morning News,4 and it later generated much controversy worldwide. Authorities that undertake or demand such screening should be made aware of the observations from Hong Kong. Competing interests: None declared. 1 2 3 4
Mabey D, Flasche S, Edmunds WJ. Airport screening for Ebola. BMJ 2014;349:g6202. (14 October.) Chan LS, Cheung GTY, Lauder IJ, Kumana CR. Screening for fever by remote sensing infrared thermographic camera. J Travel Med 2004;11:273-9. Chan LS, Lo JLF, Kumana CR, Cheung BMY. Utility of infrared thermography for screening febrile subjects. Hong Kong Med J 2013;19:109-15. Hickox K. Her story: UTA grad isolated at New Jersey hospital in Ebola quarantine. Dallas Morning News 2014. www.dallasnews.com/ebola/headlines/20141025-uta-grad-isolatedat-new-jersey-hospital-as-part-of-ebola-quarantine.ece.
Cite this as: BMJ 2014;349:g6571 © BMJ Publishing Group Ltd 2014
[email protected] For personal use only: See rights and reprints http://www.bmj.com/permissions
Subscribe: http://www.bmj.com/subscribe
Page 1 of 1
Letters
LETTERS AIRPORT SCREENING FOR EBOLA
Airport screening for Ebola: current thermal scanning procedures are unreliable 1
1
Cyrus Rustam Kumana emeritus professor , Bernard M Y Cheung professor , Lung S Chan 2 professor Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong; 2Department of Earth Sciences, University of Hong Kong, Hong Kong 1
We agree with the editorial on airport screening for Ebola virus,1 which challenges the policy of enhanced screening as currently used. Whether applied to those exiting an affected area or arrivals, apart from being easily circumvented, temperature checks that depend on currently deployed thermal scanning procedures in common use are unreliable. When using remote sensing infrared thermography, the most reliable estimate of body temperature is obtained when the probe is targeted at the ear and not the forehead or face; the most accurate reading accrues if the camera points to the side of the face and is at a short distance (about 1 m) from the hotspot in the ear. These findings stemmed from research carried out in Hong Kong during and after the epidemic of severe acute respiratory syndrome.2 3 It is hardly surprising therefore that a healthcare worker arriving in New York after caring for patients with Ebola has complained about her detention and quarantine based on readings from a
forehead scanner and a confusing array of other findings. This account was first published in the Dallas Morning News,4 and it later generated much controversy worldwide. Authorities that undertake or demand such screening should be made aware of the observations from Hong Kong. Competing interests: None declared. 1 2 3 4
Mabey D, Flasche S, Edmunds WJ. Airport screening for Ebola. BMJ 2014;349:g6202. (14 October.) Chan LS, Cheung GTY, Lauder IJ, Kumana CR. Screening for fever by remote sensing infrared thermographic camera. J Travel Med 2004;11:273-9. Chan LS, Lo JLF, Kumana CR, Cheung BMY. Utility of infrared thermography for screening febrile subjects. Hong Kong Med J 2013;19:109-15. Hickox K. Her story: UTA grad isolated at New Jersey hospital in Ebola quarantine. Dallas Morning News 2014. www.dallasnews.com/ebola/headlines/20141025-uta-grad-isolatedat-new-jersey-hospital-as-part-of-ebola-quarantine.ece.
Cite this as: BMJ 2014;349:g6571 © BMJ Publishing Group Ltd 2014
[email protected] For personal use only: See rights and reprints http://www.bmj.com/permissions
Subscribe: http://www.bmj.com/subscribe
