Human Hantavirus Infections in Hungary (2018-2025): Epidemiology, Molecular Detection Across Clinical Sample Types,...

Hantaviruses are globally distributed, rodent-borne zoonotic pathogens. In Hungary, Dobrava-Belgrade virus (DOBV) and Puumala virus (PUUV) are circulating, causing hemorrhagic fever with renal syndrome and nephropathia epidemica, respectively. Due to the short viremic period, hantaviruses are primarily diagnosed by serological methods. Detection of viral nucleic acid by real-time or nested reverse transcription polymerase chain reaction (RT-PCR) is limited to samples collected in the early phase of disease. Between 2018 and 2025, 51 laboratory-confirmed hantavirus infections were identified in Hungary; 30 cases were assigned to DOBV, 20 to PUUV, and one remained undetermined. Most patients were male (82%), suggesting increased exposure-related risk. Viral RNA was detected in 21 cases, mainly from serum and whole blood samples, and sporadically from urine. In three DOBV cases, viral RNA was detectable exclusively in whole blood but not in paired serum samples. Phylogenetic analysis included four PUUV and six DOBV partial S segment sequences showing high similarity to other human- and rodent-derived samples from the region. Hantavirus infections remain infrequently diagnosed in Hungary. Our findings suggest that serum and whole blood may be useful specimen types for molecular detection, whereas urine had limited diagnostic value in our dataset.