infectious diseases
Hantavirus Infection
Hemorrhagic Fever With Renal Syndrome
Hemorrhagic fever with renal syndrome (HFRS) is a group of similar illnesses caused by hantaviruses, which includes epidemic hemorrhagic fever, Korean hemorrhagic fever, and nephropathia epidemica; these begin as a flu-like illness and may progress to shock, bleeding, and renal failure. Diagnosis is with serologic tests and polymerase chain reaction (PCR). Mortality is 6 to 15%. Treatment includes IVribavirin. Some forms of hemorrhagic fever with renal syndrome are mild (eg, nephropathia epidemica, caused by Puumala virus, as occurs in Scandinavia, the western part of the former Soviet Union, and Europe). Some are usually mild but occasionally may be severe (eg, Seoul virus that has world-wide distribution in wild brown and domesticated rats). Others are severe (eg, that caused by Hantaan virus, as occurs in Korea, China, and Russia, or by Dobrava [Belgrade] virus, as occurs in the Balkans). Infection is transmitted to humans via inhalation of rodent excreta. Incubation is about 2 weeks. In mild forms, infection is often asymptomatic. Symptomatic HFRS progresses through five phases: febrile, hypotensive, oliguric, polyuric, and convalescent ( Symptoms and signs references ). The febrile phase has a sudden onset, with high fever, headache, backache, nausea, vomiting, and abdominal pain. Relative bradycardia is present, and hypotension occurs in about 11 to 40% of febrile patients, with shock in about one-third. Seizures or severe focal neurologic symptoms occur in 1% ( Symptoms and signs references ). Hemorrhagic complications due to thrombocytopenia may develop (eg, gastrointestinal bleeding, hematuria). Renal failure develops and patients become oliguric; this phase has the highest risk of mortality. Polyuria then develops and renal function improves. 1.Sehgal A, Mehta S, Sahay K, et al: Hemorrhagic Fever with Renal Syndrome in Asia: History, Pathogenesis, Diagnosis, Treatment, and Prevention.Viruses15(2):561, 2023. Published 2023 Feb 18. doi:10.3390/v15020561 2.Lupuşoru G, Lupuşoru M, Ailincăi I, et al: Hanta hemorrhagic fever with renal syndrome: A pathology in whose diagnosis kidney biopsy plays a major role (Review).Exp Ther Med22(3):984, 2021. doi:10.3892/etm.2021.10416 Serologic testing or polymerase chain reaction (PCR) Hemorrhagic fever with renal syndrome is suspected in patients with possible exposure if they have fever, a bleeding tendency, and renal failure. Complete blood count, electrolyte levels, renal function tests, coagulation tests, and urinalysis are then done. Presumptive diagnosis of a hantaviral infection can be quickly confirmed by demonstrating the combination of thrombocytopenia, proteinuria, and microhematuria. During the hypotensive phase, hematocrit increases and leukocytosis and thrombocytopenia develop. Albuminuria, hematuria, and red blood cell and white blood cell casts may develop, usually between the 2nd and 5th day. During the diuretic phase, electrolyte abnormalities are common. Diagnosis of HFRS is ultimately based on serologic testing or PCR. Ribavirin Sometimes renal dialysis Treatment of hemorrhagic fever with renal syndrome is with IVribavirin. Supportive care, which may include renal dialysis, is critical, particularly during the diuretic phase. 