Seoul virus (SEOV) is one of the main causes of hemorrhagic fever with renal syndrome (HFRS).

In its natural reservoirs, SEOV causes an asymptomatic, persistent infection and is spread through excretions, fighting, and grooming.

Humans can become infected by inhaling aerosols that contain rodent saliva, urine, or feces, as well as through bites and scratches.

The genome of SEOV is about 12 kilobases (kb) in length and segmented into three negative-sense, single-stranded RNA (-ssRNA) strands.

Genome segments are encased in nucleoproteins to form ribonucleoprotein (RNP) complexes that are surrounded by a viral envelope that contains spikes emanating from its surface.

The genome of Seoul virus is about 12 thousand nucleotides in length[2] and segmented into three negative-sense, single-stranded RNA (-ssRNA) strands.

[2] encodes a glycoprotein precursor that is cleaved into the two spike proteins Gn and Gc during virion assembly.

The large segment, about 6.53 kb in length,[2] encodes the viral RNA-dependent RNA polymerase (RdRp), which is responsible for transcribing and replicating the genome.

The ends of each segment contain untranslated terminal regions (UTRs) that are involved in the replication and transcription of the genome.

They contain a lipid envelope covered in spike proteins made of the two viral glycoproteins, Gn and Gc.

Lineage 4 is more widespread, having been isolated from China, South Korea, Japan, Singapore, Vietnam, and the USA.

[6][14] Transmission to humans occurs mainly through the inhalation of aerosols that contain rat saliva, urine, or feces.

Early symptoms include fever, headache, lower back pain, nausea, vomiting, diarrhea, bloody stool, and the appearance of spots on the skin.

During the hypotensive phase, there is a sudden lowering of blood pressure and shock due to microvascular leakage.

[5] Seoul virus mainly circulates it China and South Korea but is found worldwide due to the global distribution of its hosts.

[18] SEOV infection is diagnosed based on observation of symptoms and testing for hantavirus nucleic acid, proteins, or hantavirus-specific antibodies.

Initially, no strict distinction was made between Seoul virus and Hantaan virus since SEOV infection caused similar but milder symptoms, so early cases of SEOV infection were often labeled as "HTNV-like" and these cases of HFRS were often called "Rattus-type HFRS".

[13] From the 1960s to the 1980s, there were a series of HFRS outbreaks in laboratory workers that worked with lab rats, which were thought to be free of rodent viruses.

These outbreaks, determined to have been caused by SEOV, were important in understanding the then-novel disease, which was given its official name by the World Health Organization.