[1] Univ Bristol, Bristol Med Sch, Populat Hlth Sci, Bristol, Avon, England
[2] Publ Hlth England, Natl Infect Serv, Field Serv, Field Epidemiol, Bristol, Avon, England
[3] Univ Bristol, Bristol Med Sch, NIHR Hlth Protect Res Unit Behav Sci & Evaluat, Bristol, Avon, England
[4] Univ Liverpool, NIHR Hlth Protect Res Unit Emerging & Zoonot Infe, Liverpool, Merseyside, England
[5] Univ Liverpool, NIHR Hlth Protect Res Unit Gastrointestinal Infec, Liverpool, Merseyside, England
[6] Publ Hlth England, Global Publ Hlth Div, UK Field Epidemiol Training Programme, London, England
[7] Publ Hlth Wales, Communicable Dis Surveillance Ctr, Cardiff, Wales
[8] Kings Coll London, Inst Psychiat Psychol & Neurosci, London, England
[9] Kings Coll London, NIHR Hlth Protect Res Unit Emergency Preparedness, London, England
[10] Publ Hlth England, Emergency Response Dept Sci & Technol, Behav Sci Team, London, England
[11] Univ Bristol, Sch Psychol Sci, Bristol, Avon, England
[12] Univ Southampton, Dept Psychol, Southampton, Hants, England