Hilary Simons1, Dipti Patel2. 1. National Travel Health Network and Centre (NaTHNaC), UCLH NHS Foundation Trust, 3rd Floor Central, 250 Euston Road, London NW1 2PG, UK. Electronic address: Hilary.Simons@lstmed.ac.uk. 2. National Travel Health Network and Centre (NaTHNaC), UCLH NHS Foundation Trust, 3rd Floor Central, 250 Euston Road, London NW1 2PG, UK. Electronic address: dipti.patel@uclh.nhs.uk.