Is the Hantavirus Threat Bigger Than Expected?

Now that there have been three confirmed deaths from the hantavirus in visitors to Yosemite National Park, U.S. officials have issued a global alert and fear that as many as 22,000 people may be in danger of contracting Hantavirus Pulmonary Syndrome following visits to the park between June and August of this year. This has many people wondering what the hantavirus is and how it is spread.

What Are Hantaviruses?

Hantaviruses are a particular set of viruses found in rodents. North American deer mice carry a strain called the Sin Nombre virus. It is this virus that causes Hantavirus Pulmonary Syndrome, or HPS, in humans.

Symptoms of the disease typically set in as early as one week to as late as six weeks after being exposed. At the onset, symptoms resemble those of the flu, with muscle aches, fever, nausea, fatigue, vomiting, and headaches. As the disease progresses, the lungs start to fill with fluid, causing breathing difficulties. At this point, hospitalization is usually required. HPS is a severe disease, with death resulting in roughly one-third of all people who contract it.

How Is HPS Spread?

Although the deer mouse is the main carrier of hantavirus in the United States, it is a good idea to avoid all rodents. Infected rodents pass the virus to one another, but show no signs of symptoms. Infected rodents spread the virus through saliva, urine, and droppings.

When a person breathes contaminated dust from these excretions, they can contract HPS. Predators, snakes, and pets cannot become infected and, to date, there is no evidence that humans can pass the disease to each other. The length of time the virus remains infectious once excreted depends upon temperature, humidity, and other environmental factors. As such, it is a good idea to treat all rodent droppings as if they are infectious.

Preventative Measures

In order to minimize the risks of exposure to hantavirus, it is important to keep your home and workplace free of rodents. If rodents are discovered, they should be disposed of immediately and the areas need to be thoroughly cleaned.

When cleaning, wear nitrile, vinyl, or latex gloves. Wet the area thoroughly with a 10% solution of bleach. Allow the mixture to soak in for 10 minutes then remove nests and droppings with a damp towel. Finally, mop or wash the area with the bleach solution. If upholstered or carpeted surfaces have been exposed to rodents, steam clean thoroughly. Before removing cleaning gloves, disinfect them thoroughly with soap and water or disinfectant. Remove the clean gloves and wash hands thoroughly with soap and warm water or use alcohol-based hand sanitizer.