Haantavirus

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Haantavirus

Importance

Hantaviruses are a large group of viruses, carried in rodents and insectivores worldwide, which can cause disease in people who become accidental hosts. Each virus appears to have co-evolved with its reservoir host, and does not usually cause illness in this animal. In humans, the penalties of pollution depend with the virus. Although some hantaviruses tend to be associated with asymptomatic infections or mild disease, others have case fatality rates of 50% or greater. Hantavirus infections are fairly common in parts of Asia and Europe. Although hantavirus-associated disease was first reported in the United States in the 1990s during an outbreak in the Four Corners region, these viruses are not new to the U.S. Since the 1990s, they have been reported in rodents and insectivores throughout the country, and additional human cases have been found. There is serologic evidence that some domesticated animals may also become accidental hosts for hantaviruses, but little or no evidence of disease.

Etiology

Hantaviruses (genus Hantavirus, family Bunyaviridae) are a group of antigenically distinct viruses carried in rodents and insectivores (shrews). Each hantavirus is endemic in one, or at most, a few specific rodent or insectivore hosts, to which it is well adapted. At least 20 hantaviruses have been identified, but estimates of the exact number of viruses vary. Newly identified hantaviruses are often named for the location where the virus is found; however, some of these viruses are later reclassified. The Laguna Negra, Rio Mamore, Oran, Lechiquanas and Pergamino viruses, which were once thought to be separate hantaviruses, are now considered to be variants of Andes virus, and the New York virus and Monongahela virus are currently classified as variants of Sin Nombre virus. One variant of Dobrava virus (DOBV-Aa) is also called Saaremaa virus; whether this is a separate virus or a less pathogenic variant of Dobrava virus is controversial. Some hantaviruses have not yet been named.

Different hantaviruses cause hemorrhagic Fever with Renal Syndrome (HFRS) and hantavirus pulmonary syndrome (HPS), the two syndromes seen in humans. Hemorrhagic fever with renal syndrome is a group of clinically similar diseases that occur mainly in Europe and Asia. The most important hantaviruses causing HFRS are Hantaan virus, Puumala virus, Dobrava virus and Seoul virus. Other hantaviruses such as Amur virus are furthermore affiliated with this disease. HFRS includes several diseases that formerly had other names, including Korean hemorrhagic fever and epidemic hemorrhagic fever. ”Nephropathia epidemica” is sometimes used for a mild form of HFRS, which is often caused by Puumala virus or Saaremaa virus.

Hantavirus pulmonary syndrome is caused by a number of hantaviruses in North and South America. In the United States and Canada, the Sin Nombre virus (with its Monongahela and New York variants) is responsible for most cases. HPS can also result from infection by the Muleshoe, Black Creek Canal and Bayou viruses , as well as other named or unnamed hantaviruses. In South and Central America, Andes virus and its variants are important causes of HPS, and Choclo, Castelo ...