Ebola virus disease: temperature checks for travelers?

Recently, the director of the Centers for Disease Control and Prevention (CDC) expressed confidence in screening measures being taken at the international airports in West Africa to prevent the spread of Ebola virus disease. Temperature checks for travelers in West Africa have emerged as the favoured front-line, last-minute defense for containing the spread of Ebola virus disease. In concordance, the World Health Organization (WHO) added temperature checks to the list of measures to be taken at airports, seaports and border crossings for travelers arriving from West Africa (1). Do we really believe that temperature checks for travelers could control the spread of Ebola virus disease? In 2009, WHO recommended temperature checks for travelers at all national and international airports during influenza A (H1N1) pandemic. Should we apply the same preventive measure to control the spread of Ebola virus disease? No doubt, this measure could not be applied to control the spread of Ebola virus disease because of several reasons: First, the typical incubation period for influenza is 1–4 days (average 2 days), meanwhile the incubation period for Ebola virus disease is 2 to 21 days (average 14 days). A patient may travel for weeks without fever or any other symptom during the long incubation period (up to 6 weeks in some reported cases) (2). Second, detecting a traveler with fever will produce unnecessary alarm in the whole airport and among travelers since, according to WHO and CDC, this traveler should be isolated until having negative results for Ebola virus disease (1, 2). Third, fever is a non-specific symptom of many infectious diseases including common cold. We expect, as usually, many cases of influenza virus infection characterized by high fever (> 38 oC) during autumn and winter months. Fourth, controls for body temperature at airports did not seem to be effective in preventing the influenza A (H1N1–2009) spread. In 2009, a study was done at Narita International Airport (Japan) to retrospectively assess the feasibility of detecting influenza cases upon relying solely on fever screening. The results of the study showed that the sensitivity of fever for detecting influenza A (H1N1–2009) cases upon arrival was estimated to be 22.2% among confirmed influenza A (H1N1–2009) cases (3). Fifth, the above mentioned study reported that about 55.6% of influenza A (H1N1–2009) cases were under antipyretic medications upon arrival (3). In conclusion, we could not apply the same preventive measures to control different infectious diseases, especially alarming ineffective measure like controls for body temperature at airports.