On 28 October 2024, the US Center of Disease Control and Prevention reported a suspected imported case of Lassa fever in an Iowa resident. The case recently to West Africa (country unspecified) in early October 2024 and became ill upon return and was isolated in a hospital where he died end of October.

Lassa fever is endemic in West Africa with 100’000 to 300’000 cases reported each year.

Sporadic cases have been reported among returning travellers: In the past 10 years, EU/EEA countries have reported seven Lassa fever cases to ‘The European Surveillance System’ (TESSy). Two cases were reported by the UK (ex-Nigeria and ex-Mali) in 2009, one by Sweden (ex-Liberia) in 2016, two by Germany (ex-Togo and a secondary case infected in Germany) in 2016 and two by the Netherlands (ex-Sierra Leone) in 2019. In the USA, there have been nine imported Lassa fever cases since 1969.