Hantavirus

There seems to be no dearth of viruses that are linked to animals and that are affecting humans. One such virus is the orthohantavirus or hantavirus which normally infects rodents but does not cause disease in them. However, humans can become infected with hantaviruses if they come into contact with the urine, saliva, or feces of the infected rodent. The hantavirus is named after the Hantan River area in South Korea where an early outbreak was observed.

The hantavirus carries some strains that can cause potentially fatal diseases in humans like hantavirus hemorrhagic fever with renal syndrome (HFRS), or hantavirus pulmonary syndrome (HPS), which is also known as hantavirus cardiopulmonary syndrome (HCPS). The hantavirus cardiopulmonary syndrome or HCPS is a rare respiratory illness associated with the inhalation of aerosolized rodent excreta contaminated by hantavirus particles.

Hantavirus Hemorrhagic Fever With Renal Syndrome:

HFRS is also known as Korean hemorrhagic fever and epidemic hemorrhagic fever, and the species that cause HFRS include Hantaan orthohantavirus, Dobrava-Belgrade orthohantavirus, Saaremaa virus, Seoul orthohantavirus, Puumala orthohantavirus and other orthohantaviruses. It is found in Europe, Asia, and Africa.

Of these species, Hantaan River virus and Dobrava-Belgrade virus cause the most severe form of the syndrome and have the highest morbidity rates.

Hantavirus Pulmonary Syndrome:

HPS is an often fatal pulmonary disease and was first recognized during the 1993 outbreak in the Four Corners region of the southwestern United States. Identified by Dr. Bruce Tempest, its original name was Four Corners disease, which was later changed to Sin Nombre virus. In the United States, the causative agent is the Sin Nombre virus carried by deer mice.

Hantavirus Survivability:

How long the hantaviruses remain infectious in the environment is based on a number of factors like the rodent's diet, temperature, humidity, and whether indoors or outdoors. It has been known to remain active for two to three days at normal room temperature, while ultraviolet rays in direct sunlight kills them within a few hours. But all rodent droppings and urine, no matter how long they have been present, should be treated as infectious.

Signs And Symptoms of HFRS:

Hemorrhagic fever with renal syndrome (HFRS) is part of a group of similar illnesses caused by species of hantaviruses from the family Hantaviridae. Symptoms of HFRS usually develop within 1 to 2 weeks after exposure to infectious material, but sometimes may take up to 8 weeks to develop.

The initial symptoms begin suddenly and include intense headaches, back and abdominal pain, fever, chills, nausea, blurred vision, flushing of the face, inflammation or redness of the eyes, or a rash. Later symptoms can include low blood pressure, acute shock, vascular leakage, and acute kidney failure, which can cause severe fluid overload. In hantavirus-induced hemorrhagic fever incubation time is two to four weeks in humans before symptoms develop.

The severity of the disease varies depending upon the virus causing the infection. Hantaan and Dobrava virus infections usually cause severe symptoms, while Seoul, Saaremaa, and Puumala virus infections are usually more moderate.

Signs And Symptoms of HPS:

Where hantavirus pulmonary syndrome is concerned, it includes flu-like symptoms such as fever, cough, muscle pain, headache, and lethargy. Main characteristics include sudden onset of shortness of breath with rapidly evolving pulmonary edema that is often fatal even with mechanical ventilation and potent diuretics.

Treatment And Recovery:

There is no specific treatment, cure, or vaccine for hantavirus infection, but recovery is possible with supportive treatment. People with suspected hantavirus infection may be hospitalised and given oxygen and mechanical ventilation support which would help them breathe better. The earlier the patient is brought in to intensive care, the better. If a patient is experiencing full distress, it is less likely the treatment will be effective. Complete recovery can take weeks or months.

People who have been around rodents and have symptoms of fever, deep muscle aches, and severe shortness of breath should see their doctor immediately. They should inform their doctor that they have been around rodents, as this will alert the physician to look closely for any rodent-carried disease, such as HPS.

Prevention of Hantavirus:

The best way to prevent hantavirus contraction is to eliminate or have as little as possible or no contact at all with rodents whether at home, workplace or outdoors. Since the virus can be transmitted to humans through rodent saliva, urine, feces and bites, it is important to keep a check on rats and mice in areas frequented by humans to prevent the disease from spreading.

Other ways of preventing the disease is by destroying rodent nests, sealing cracks and crevices at home through which rats and mice can get through, setting up traps or laying down poisons.