October 9, 2014

expert reaction to announcement that there will be enhanced screening of passengers arriving from Ebola-infected countries to the UK

The government has announced that passengers travelling from countries affected by Ebola and arriving at Heathrow, Gatwick and Eurostar terminals will be subjected to “enhanced screening”, through questions about their health and possible medical assessments.

Dr Ben Neuman, Lecturer in Virology, University of Reading, said:

“I don’t think there is a strong scientific case that airport screening will help keep Ebola out of the UK, but it’s a step that will reassure some people. Screening sounds like a good idea at first, but it would be difficult to put an effective Ebola screening programme into practice.  Checking passengers arriving from Liberia, Sierra Leone and Guinea for fevers is a reasonable precaution, but most people who are well enough to travel on a plane would pass the new screening measures regardless of whether they were infected.

“Even for experienced doctors, Ebola is a difficult disease to detect.  The first few weeks after infection, a person would not normally have any external signs of having Ebola. Early-stage Ebola cases could only be detected by an invasive blood test, and even that might fail if the person has very recently contracted the virus.  The only surefire way to keep Ebola out of the UK is to stop it at the source – by measures like providing new hospitals and the people needed to mount a joined-up public health response in west Africa.”

Prof David Evans, Professor of Virology, University of Warwick, said:

“The recent announcement on the introduction of “enhanced screening” of inbound passengers at major airports and Eurostar terminals is probably the most that can be done to balance practicality and effectiveness with the need to reassure the UK public that their health is being protected. It is important to remember that it can take as much as 3 weeks after infection for symptoms to develop, during this period the individual is non-infectious. Therefore, knowledge of the recent travel history and contacts of passengers is likely to be more effective in identifying potentially infected people for subsequent follow-up. Passenger temperatures are already taken on exit from West African airports and it would be both impractical and largely ineffective to routinely screen inbound passengers for high temperatures. The early symptoms of Ebola, such as fever, resemble many infectious diseases and reliance on temperature screening alone would identify many that would be ‘false-positives’, for example from malaria or non-specific respiratory tract infections. Similarly, ‘false-negative’ – passengers arriving without a fever but that are infected with Ebola – would still escape detection. Use of temperature screening was not effective in identifying passengers with SARS during the 2003 epidemic and there is no reason to think it would be any better in identifying passengers infected with Ebola.

“It is also important that the screening announced does not create a false sense of security. It will only be as good as the accuracy of the travel and contact history available for passengers. The very best way to protect the UK population (and the global population) is to control the spread of infection in West Africa. This has been achieved in every previous outbreak by the application of quarantine, barrier protection for healthcare workers, training and good hygiene. These methods should be effective in this outbreak if applied rigorously and if sufficient resources and support are provided to enable their deployment. This must remain the priority.”

Prof Tom Solomon, the University of Liverpool’s Head of Infection and Global Health, and Director of the NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, said

“It is understandable that the Government wants to do everything possible to reduce the chances of Ebola coming to the UK; and the public will be reassured to learn that everything possible is being done. The evidence suggests that such measures won’t make a large difference, above the screening which already takes for people leaving affected countries in West Africa. It is also important to remember that people may be infected, and incubating the disease, but not yet have any symptoms, and screening will not detect them. It is therefore important that people who return from west Africa and feel unwell seek medical help whether or not they have been screened.”

Prof Julian Hiscox, Professor of Infection Biology, University of Liverpool, said:

“The key to prevent and control an Ebola virus epidemic is information and breaking the transmission cycle and this is a sensible measure to introduce.  The availability of rapid field based diagnostics would greatly help in our nation’s preparedness.”

Declared interests

Julian Hiscox is funded through the National Institute of Health Research and the Defence Science Technology Laboratory to work on Ebola virus.