Seoul virus

Seoul virus (SEOV), formally Seoul orthohantavirus, is one of four major hantavirus species that cause significant human disease worldwide. Unlike most hantaviruses, which are geographically confined to a single rodent reservoir species, Seoul virus has a global distribution because its primary reservoir is the brown rat (Rattus norvegicus), which has spread across the world through human commerce. It causes Hantavirus Fever with Renal Syndrome (HFRS), a kidney-damaging illness, rather than the pulmonary syndrome (HCPS) caused by Andes or Sin Nombre virus. HFRS case-fatality rates for Seoul virus are lower than for Hantaan virus (the other major HFRS agent), typically under 1%. There is no documented person-to-person transmission of Seoul virus.

Seoul virus is cited in the MV Hondius briefing as a reference point for understanding what makes Andes virus unusual. The briefing notes that 'Andes, unlike Sin Nombre or Seoul virus, can bridge between people in confined settings' . This contrast is load-bearing for the risk assessment: Seoul and Sin Nombre are rodent-to-human only, which limits outbreak size. Andes maintains that rodent-origin route but adds a person-to-person transmission capability in close-quarters settings such as households or, as the MV Hondius cluster illustrates, cruise ship cabins. Seoul virus's global presence via brown rats gives it pandemic-geography potential that Andes lacks, but without person-to-person spread, the surveillance concern is different.