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Scientists react to statements made by director general of Africa Centres for Disease Control and Prevention, Jean Kaseya, on feasibility of Ebola outbreak reaching the UK
Dr Charlotte Houldcroft, Assistant Professor of Virus Genomics, University of Cambridge, said:
How could it [spread to UK] happen?
“The UK is at risk from any infectious disease with a long incubation period. People can be exposed abroad, travel feeling well, but be incubating an infection that they fall ill with once back in the UK. Ebolavirus infections normally incubate for 8-10 days, but it can be as long as 21 days before in infected person shows symptoms. That’s a wide window for travellers to fly home not knowing they are sick.
How well prepared do you think the UK would be to detect and respond?
“The rapid diagnostic capacity developed for COVID, such as within-A&E PCR testing, means that the NHS has the diagnostic equipment to rapidly test for ebolavirus if needed. There’s also a lot of knowledge gained from the 2014-2016 Western Africa Ebola outbreak, when UK cases occurred in health care workers and members of the military exposed abroad but treated in the UK.
Should the British public be concerned about the risk?
“This isn’t a situation like Covid. Ebola typically spreads a bit more slowly than SARS-CoV-2, giving measures like contact tracing time to catch up with suspected cases. There are vaccine candidates and drugs already in clinical trials. We also know how to stop ebolavirus spreading in healthcare settings.”
Prof Sir Andrew Pollard, Director of the Oxford Vaccine Group and Ashall Professor of Infection and Immunity, Pandemic Sciences Institute and Department of Paediatrics, University of Oxford, said:
“The head of the African CDC is right that we should all be concerned about Ebola because of the awful ongoing outbreak in DRC with a huge human cost there, and ongoing risk of spread to surrounding countries. Previous outbreaks have been controlled by diagnosing and isolating infected individuals, identifying and monitoring their at-risk contacts and protecting frontline workers. All of these measures are difficult to put in place in regions with poor health infrastructure, difficult to access populations and insecurity, and these factors have hampered control efforts in DRC. However, in high income settings such as the UK, medical plans are already in place and the public health infrastructure is well equipped to respond to any case (such as might occur in a returning aid or health worker) and to contain onward spread. Work continues at pace to develop new treatments, and a vaccine against this strain of Ebola. If successful, a vaccine could help end the current outbreak and also protect those who might be exposed in the future.“
Prof Paul R. Hunter, Professor in Medicine, Director NIHR Health Protection Unit in Gastrointestinal Infections, University of East Anglia, said:
“There are several levels in this that need to be considered.
Could there be a case in the UK?
“The answer is clearly yes as there have been several cases already in Europe from this epidemic, mostly in people who were repatriated when they became ill but a case became ill after returning to France. In previous epidemics there have also been occasional cases imported into countries outside of Africa.
Could there be transmission from an imported case?
“Yes, there could but is pretty rare, I am only aware of three previous infections one in Spain and two in the US. All were health care workers. So, although secondary infections outside of Africa have been reported, the risk is small and at present limited to health care workers.
Could there be sustained person-to-person transmission of Ebola in the UK?
“Almost certainly not.
“The fact is that Ebola is not that transmissible and usually requires close contact with a case or their body fluids. Furthermore, the infectiousness of a case increases as the case becomes more ill and especially as the approach death. See our paper written during the West African epidemic[1]. Also, funereal practices that are common in Africa and rare in Europe are an important risk for transmission. In this country cases would be most likely be in hospital when they are most infectious. Also, once one case was identified contacts would be monitored closely to identify secondary cases at a point before they became particularly infectious.
“So, although nothing is impossible with infectious diseases, the risk to UK public health that it would become a hotspot of Ebola remains very low. But the risk remains of importation of a case remains and there is a low risk that we could see a small number of secondary infections.”
[1] https://academic.oup.com/ije/article/45/1/102/2363618
Declared interests
Dr Charlotte Houldcroft: “Houldcroft lab receives unrelated funding through the BBSRC iCASE DTP, in collaboration with Virothera Ltd.”
Prof Sir Andrew Pollard: “I am director of the Oxford vaccine group at University of Oxford, which is developing Ebola vaccines.”
Prof Paul R. Hunter: “None to report.”