Hemorrhagic Fever Renal Syndrome

Hemorrhagic fever with renal syndrome (HFRS) is a disease transmitted through aerosolized urine or feces of rodents (mice, rats, shrews, and voles). HFRS is the most common zoonosis in Asia and also common in parts of Europe. Various serotypes cause the disease within the genus and are endemic in parts of Asia and Eastern Russia. The most common serotypes causing HFRS are and . Rodents are asymptomatic reservoirs of the virus, which can spread to infect humans at a rate of over 100,000 cases per year. The outcome of infection is usually self-limited, but mortality can exceed 15% with some infectious strains.  Recently, the taxonomical classification of these viruses has been updated. Due to a plethora of newly sequenced viral genomic data, classifications were expanded in 2016 to include Bunyavirales as an order, and the previous genus became the family classification Hantaviridae. The viruses causing hemorrhagic fever with renal syndrome are part of the O genus and Hantaviridae family (previously referred to as Hantaviruses).  Two main disease processes result from (which will be referred to as Hantaviruses from here on out): Hemorrhagic fever with renal syndrome (HFRS) and Hantavirus cardiopulmonary syndrome (HCPS). These two entities have distinct presentations and geographic predominance; the viruses causing HFRS circulate in Asia and Eastern Europe, while the viruses causing HCPS are found in the Americas. Different Hantavirus strains cause HFRS and HCPS and have different clinical pictures, but both involve increased microvascular permeability, consumptive platelet coagulopathy, and hyperactivity of the host immune system. HCPS is associated with much higher mortality.  Please see our companion StatPearls topic "Hantvirus Cardiopulmonary Syndrome," for further information. HFRS results from inhalation of Hantavirus, which spreads to other organ systems through the immune system and targets the renal vasculature. In patients who develop HFRS, a variety of clinical presentations exist, from mildly symptomatic to death. No known cure exists for Hantavirus infection other than supportive care.