Case series of Oropouche fever among travellers returning from Cuba to Spain, 2024.

Oropouche fever is a vector-borne disease endemic in Central and South America. Infection with Oropouche virus (OROV) was confirmed in June and July 2024 in 13 patients travelling from Cuba to Spain. These patients presented fever, headache, myalgia and arthralgia, and three patients exhibited a biphasic course, with two developing transient neurological symptoms. Oropouche virus infection was diagnosed using reverse transcription quantitative PCR (RT-qPCR) and neutralisation tests. Viral RNA was detected in specimens from serum, urine, plasma and whole blood; from four urine samples up to 24 days post-symptom onset. Phylogenetic analysis of one OROV strain (OROV SP2024) isolated from one patient, demonstrated it clustered closely with reassortant strains circulating in Brazil and imported cases in Italy. These findings underscore the importance of including OROV in the differential diagnosis of febrile illnesses in returning travellers and demonstrate the diagnostic value of analysing multiple sample types. Enhanced clinical awareness and diagnostic capacity are essential to improve detection and surveillance of OROV among international travellers from affected regions.