[1] Univ Liverpool, Dept Epidemiol & Populat Hlth, Inst Infect & Global Hlth, Leahurst Campus,Chester High Rd, Neston CH64 7TE, Cheshire, England
[2] Aberystwyth Univ, Inst Biol & Environm & Rural Sci, Aberystwyth SY23 3DA, Dyfed, Wales
[3] Univ Liverpool, Hlth Protect Res Unit Emerging & Zoonot Infect, Neston CH64 7TE, Cheshire, England