A 50 year old British national working in Daru, Sierra Leone became ill with fever on 21 February and was airlifted to Freetown. He remained unwell, and on 5 March was evacuated to the UK by air ambulance. He was admitted to the Hospital for Tropical Diseases, London, and then transferred to Coppetts Wood Hospital, where he is being managed in high security isolation facilities.
Lassa fever is suspected on the basis of clinical findings and preliminary test results.
Tests for other known viral haemorrhagic fevers have so far proved negative. Confirmatory tests for Lassa fever are in progress at the Enteric and Respiratory Virus Laboratory, Central Public Health Laboratory, London, and the results are expected within 24 hours. Over 90 potential contacts of this patient have been identified, both in Sierra Leone and the UK . All have been contacted and are being monitored. For further information on Lassa fever, please see the WHO Fact Sheet on Lassa fever.