Hantavirus hemorrhagic fever with renal syndrome, Puumala virus type

Hantavirus hemorrhagic fever with renal syndrome

Hantavirus hemorrhagic fever with renal syndrome (HFRS) is a hemorrhagic fever caused by hantavirus infection. Symptoms usually occur 2 weeks after exposure to the hantavirus and come in five distinct clinical stages: febrile (toxic), hypotensive, low urine production (oliguric), high urine production (diuretic), and recovery. Early symptoms include headache, lower back pain, nausea, vomiting, diarrhea, bloody stool, the appearance of spots on the skin, bleeding in the respiratory tract, and renal symptoms such as kidney swelling, proteinuria, and hematuria. During the hypotensive phase, blood pressure lowers due to microvascular leakage. Renal failure then causes the oliguric phase, before recovering and increasing urine production as disease progression improves. The severity of symptoms varies depending on which virus causes HFRS and ranges from mild illness to severe. The case fatality rate likewise varies by virus, from less than 1% up to 15%. HFRS is caused mainly by four viruses in Asia and Europe: Hantaan virus, Seoul virus, Puumala virus, and Dobrava-Belgrade virus. In East Asia, Hantaan virus is the most common cause of HFRS, causes a severe form of HFRS, and is spread by striped field mice. The Seoul virus accounts for about a quarter of HFRS cases, causes a moderate form of the disease, and is found worldwide due to the global distribution of its natural reservoir, the brown rat. Puumala virus is the most common cause of HFRS in Russia and northern and central Europe, usually causes a mild form of HFRS, and is transmitted by the bank vole. The Dobrava-Belgrad...