Funding for this research was provided by:
Wellcome Trust (12425/1.5/SC)
Received: 17 February 2020
Accepted: 8 May 2020
First Online: 16 May 2020
Ethics approval and consent to participate
: Royal Postgraduate Medical School Home Office licence ELA 24/4994.
: The authors Michael Beverly and David Murray consent to publication.
: There are no competing interests.