HANTAVIRUSE

Hantaviruses are single-stranded, enveloped, negative sense RNA viruses in the Bunyaviridae family. Humans may become infected with hantaviruses through contact with rodent urine, saliva, or feces. Some strains of hantaviruses cause potentially fatal diseases in humans, such asHantavirus hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS), while others have not been associated with known human disease.Human infections of hantaviruses have almost entirely been linked to human contact with rodent excrement, but recent human-to-human transmission has been reported with the Andes virus in South America.The name hantavirus is derived from the Hantan River area in South Korea, for which Hantaan virus is named. It was isolated in the late 1970s by Karl M. Johnson and Ho-Wang Lee.The hantaviruses are a relatively newly discovered genus of viruses. An outbreak of Korean Hemorrhagic Fever among American and Korean soldiers during the Korean War (1951–1953) was later found to be caused by a hantavirus infection. More than 3000 troops became ill with symptoms that included renal failure, generalized hemorrhage, and shock. It had a 10% mortality rate. This outbreak sparked a 25-year search for the etiologic agent. Ho-Wang Lee, a South Korean virologist, Karl M. Johnson, an American tropical virologist, and his colleagues isolated Hantaan virus in 1976 from the lungs of striped field mice.

Two major clinical syndromes

Hemorrhagic fever with renal syndrome

Main article: Hantavirus hemorrhagic fever with renal syndrome (HFRS)

Hemorrhagic fever with renal syndrome (HFRS) is a group of clinically similar illnesses caused by species of hantaviruses from the family Bunyaviridae. It is also known as Korean hemorrhagic fever, epidemic hemorrhagic fever, and nephropathis epidemica. The species that cause HFRS include Hantaan River, Dobrava-Belgrade, Saaremaa, Seoul, and Puumala. It is found in Europe, Asia, and Africa.

In hantavirus induced hemorrhagic fever, incubation time is between two to four weeks in humans before symptoms of infection present. Severity of symptoms depends on the viral load.

Hantavirus pulmonary syndrome

Hantavirus pulmonary syndrome (HPS) is found in North, Central and South America.It is an often fatal pulmonary disease. In the United States, the causative agent is Sin Nombre virus carried by deer mice. Prodromal symptoms include flu-like symptoms such as fever, cough, myalgia, headache, and lethargy. It is characterized by a sudden onset of shortness of breath with rapidly evolving pulmonary edema that is often fatal despite mechanical ventilation and intervention with potent diuretics. It has a fatality rate of 38%.

Entry into host cells is thought to occur by attachment of virions to cellular receptors and subsequent endocytosis. Nucleocapsids are introduced into the cytoplasm by pH-dependent fusion of the virion with the endosomal membrane. Subsequent to release of the nucleocapsids into cytoplasm, the complexes are targeted to the ER-Golgi Intermediate compartments (ERGIC) through microtubular associated movement resulting in the formation of viral factories at ERGIC.The species that cause hantavirus hemorrhagic fever have not been shown to transfer from person to person. Transmission by aerosolized rodent excreta still remains the only known way the virus is transmitted to humans. Similar negative-stranded RNA viruses, such as Marburg and Ebola hemorrhagic fevers, can be transmitted by contact with infected blood and body fluids, and are known to spread to patient-care workers in African hospitals. But those viruses do not transfer readily in the modern hospital setting with universal precautions. In general, drop-let and/or fomite transfer has not been shown in the hantaviruses in either the hemorrhagic or pulmonary forms