Tag Archives: pulmonary disease

A New Understanding Of Hantavirus

Hantavirus is a infectious agent first discovered along the Hantan River in in South Korea. Depending on which specific kind of hantavirus is involved, infection generally results in one of two illnesses.

One, found primarily in Europe and Asia, is called "hantavirus hemorrhagic fever with renal syndrome." It is sometimes fatal, and may completely destroy the kidneys. With medical care, however, it is survivable. Treatment to protect renal function including dialysis, makes it possible for the patient to live until the disease starts to clear up on its own.

The other disease, more common in the Americas, is called "hantavirus pulmonary syndrome." This, as the name suggests, is a pulmonary disease, causing flu-like symptoms. It has lead to around 200 deaths in the United States, around a third of people who have been diagnosed with the pulmonary disease in the 20 years since it was first identified as a separate condition. The various kinds of hantavirus are transmitted through rodent droppings, which can get into poorly protected food supplies, particularly when a person is camping.

Earlier this year, researchers announced that they had developed a model of how a hantavirus infection spreads within the body. The research team said they now have a more complete understanding of where a hantavirus infection starts, of how it triggers a potentially fatal immune response, and of the link between hantavirus infection and pneumonia. This clearer picture of the disease could potentially lead to better, more efficient, and more effective treatments.

Earlier research demonstrated how cholesterol provides hantavirus with some of the resources it needs for its attack on the body of its host. Hantavirus uses one of the proteins responsible for cholesterol production as a handhold into cells in the pulmonary system The researchers found that drugs affecting this protein provide some measure of defense against hantavirus infection. They further found that cholesterol-lowering statin drugs can also help provide similar protection. This is important, because hantavirus, like many viruses, is notoriously difficult to treat directly. It becomes resistant to drugs within a short time, making a direct approach not useful in the long term. By using statins to root out the viruses’ support system, doctors may be able to treat this highly deadly disease more effectively.

Who Helps Fight Hantavirus?

Although a year only sees about 30 hantavirus infection in the United States—in part because it is not contagious but is transmitted by particulate dust in the feces of rodents—it is one of the deadliest viruses. The mortality rate from hantavirus pulmonary infection is believe to be as high as 40 percent. The virus produces flu-like symptoms, such as fever, headaches, nausea, diarrhea, and abdominal pain, but starts to affect the lungs and heart in as little as four days. That means it is important that anyone who may have been exposed to rodent droppings and exhibits these symptoms seek medical attention right away.

In a recent study, scientists identified four proteins that were involved in hantavirus infection. The proteins are part of the mechanism that regulates the production of cholesterol. That means that statin drugs, taken to help lower cholesterol, can also be effective against hantavirus, helping to prevent infection. Another, experimental drug that works directly on the proteins involved also reduces hantavirus infection risk.

Another way to prevent the illness is to eliminate the primary transmission vector, the rats responsible for transmitting the virus to humans. In Chile, home of a common strain known as Andes virus, owls are being used to keep the rat population down. In Chilean forests, campers and others are prone to getting the disease from the long-tailed pygmy rice rat, an asymptomatic carrier of the disease. The rats, however, are prey for two species of owl native to the Andes Mountains. Although local beliefs connect the hooting of the owls with death, their presence actually helps control the rice rat population and prevent the spread of disease.

Other prevention efforts similarly focus on eliminating the rodents themselves. This means closing holes where the pests can get in getting rid of trash and other material they can use to make nests, getting rid of food garbage they can eat, and, in some cases, setting traps. Cleaning rodent-infested areas with bleach will kill the virus in dust and prevent live virus from being inhaled. There is no antiviral treatment for hantavirus, so when someone has been infected, treatment generally entails addressing the symptoms and a ventilator to provide assisted respiration as the infection runs its course.