Article History
Received: 14 January 2019
Accepted: 26 September 2019
First Online: 15 October 2019
Ethics approval and consent to participate
: This study retrospectively reports clinical health protection work, and as such it is classified as ‘usual practice’ by the NHS Health Research Authority []. Therefore, ethical approval and research ethics committee review was not required, and informed consent was not obtained from participants in advance.
: Not applicable.
: The authors declare that they have no competing interests.