1. Healthy Infrastructure Research Centre, Civil, Environmental and Geomatic Engineering, University College London, London, UK; and Department of Microbiology and Infectious Diseases, Nuffield Department of Clinical Medicine, University of
Oxford, John Radcliffe Hospital, Oxford, UK
2. North East and North Central London Health Protection Unit, London, UK
3. Healthy Infrastructure Research Centre, Civil, Environmental and Geomatic Engineering, University College London, London, UK