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Hantavirus viruses normally infect rodents, but do not cause disease in them.

Humans may become infected with hantaviruses through contact with rodent urine, saliva, or feces. Some strains cause potentially fatal diseases in humans, such as hantavirus hemorrhagic fever with renal syndrome (HFRS), or hantavirus pulmonary syndrome (HPS), also known as hantavirus cardiopulmonary syndrome (HCPS), while others have not been associated with known human disease. HPS (HCPS) is a “rare respiratory illness associated with the inhalation of aerosolized rodent excreta (urine and feces) contaminated by hantavirus particles.”

Human infections of hantaviruses have almost entirely been linked to human contact with rodent excrement; however, in 2005 and 2019, human-to-human transmission of the Andes virus was reported in South America.

Hantavirus is named for the Hantan River area in South Korea where an early outbreak was observed, and was isolated in 1976 by Ho-Wang Lee.

SYMPTOMS OF HANTAVIRUS

Hemorrhagic fever with renal syndrome

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

In hantavirus-induced hemorrhagic fever incubation time is two to four weeks in humans before symptoms develop. Their severity 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 the Sin Nombre virus carried by deer mice. Prodromal symptoms include flu-like symptoms such as fever, cough, muscle pain, headache, and lethargy. It is characterized by a sudden onset of shortness of breath with rapidly evolving pulmonary edema that is often fatal despite intervention with mechanical ventilation and potent diuretics. The fatality rate is 36%.

Hantavirus pulmonary syndrome was first recognized during the 1993 outbreak in the Four Corners region of the southwestern United States. It was identified by Dr. Bruce Tempest. It was originally called “Four Corners disease,” but the name was changed to “Sin Nombre virus” after complaints by Native Americans that the name “Four Corners” stigmatized the region. It has since been identified throughout the United States. Rodent control in and around the home remains the primary prevention strategy.

HOW HANTAVIRUS TRANSMITTED | SPREAD IN POPULATION

Transmission OF HANTA VIRUS

The viruses that cause hantavirus hemorrhagic fever have not been shown to transfer from person to person, except for Andes virus. For other species of hantavirus, aerosolized rodent excreta or rodent bites are the only known routes of transmission 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 healthcare workers in African hospitals, but do not transfer readily in a modern hospital setting with the appropriate precautions. Transmission through fomites (inanimate objects exposed to infection) has not been demonstrated in hantavirus disease in either the hemorrhagic or pulmonary forms.

VACCINE FOR HANTAVIRUS

As of 2016, there is no FDA-approved, commercially available vaccine against hantavirus. A vaccine known as Hantavax has been under study since 1990. As of 2016, the development was in clinical phase 3 trial stage. This inactivated vaccine is thought not to be effective against European hantaviruses like the Puumala (PUUV) virus.  A killed-virus vaccine is not being pursued because of the dangers associated with mass production under high containment as well as the unresolved questions about the efficiency of the vaccine. A number of labs have been working towards a vaccine that would deliver viral antigens by either DNA vectors or as recombinant proteins. As of 2016, these recombinant vaccines will not be available in the near future.

No WHO-approved vaccine has gained widespread acceptance, but the Korean Army is one of the largest consumers of a hantavirus vaccine, second only to public health centers.

TREATMENT FOR HANTAVIRUS

Ribavirin may be a drug for HPS and HFRS but its effectiveness remains unknown, still, spontaneous recovery is possible with supportive treatment. People with suspected hantavirus infection may be admitted to the hospital, given oxygen and mechanical ventilation support to help them breathe during the acute pulmonary stage with severe respiratory distress. Immunotherapy, administration of human neutralizing antibodies during acute phases of Hantavirus, has only been studied in mice, hamsters, and rats. There are no reports of controlled clinical trials.

03/24/2020  3:53:55 PM

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