Hantavirus (or orthohantavirus) is a single-stranded, enveloped, negative-sense RNA virus in the family Hantaviridae of the order Bunyavirales. These 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.
Transmission of hantavirus
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. Transmission through fomites (inanimate objects exposed to infection) has not been demonstrated in hantavirus disease in either the hemorrhagic or pulmonary forms.
Symptoms of hantavirus
In hantavirus-induced hemorrhagic fever incubation time is two to four weeks in humans before symptoms develop. Their severity depends on the viral load. Some of the symptoms of hantavirus include:
- Nephropathia epidemica.
- Epidemic hemorrhagic fever or Korean hemorrhagic fever.
- Muscle pain or muscle achesespecially in the large muscle groups – thighs, hips, back, and sometimes shoulders
- Sudden onset of shortness of breath with rapidly evolving pulmonary edema that is often fatal despite intervention with mechanical ventilation and potent diuretics.
Prevention of hantavirus
The best prevention against contracting hantavirus is to eliminate or minimize contact with rodents in the home, workplace, or campsite. As the virus can be transmitted by rodent saliva, excretions, and bites, control of rats and mice in areas frequented by humans is key for disease prevention. General prevention can be accomplished by disposing of rodent nests, sealing any cracks and holes in homes where mice or rats could get in, setting up traps, or laying down poisons or using natural predators such as cats in the home.
The duration that hantaviruses remain infectious in the environment varies based on factors such as the rodent’s diet, temperature, humidity, and whether indoors or outdoors. The viruses have been demonstrated to remain active for two to three days at normal room temperature, while ultraviolet rays in direct sunlight kills them within a few hours. However, rodent droppings or urine of indeterminate age should always be treated as infectious.
Treatment of hantavirus
There is no approved, commercially available vaccine against hantavirus. Though Ribavirin may be a drug for Hantavirus pulmonary syndrome (HPS) and Hemorrhagic fever with renal syndrome (HFRS), 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.