Iím no expert but I have a basic knowledge of microbiology and the nature of science.
You reference http://vitals.nbcnews.com/_news/2012/09/07/13719926-yosemite-doubles-scope-of-hantavirus-warning-to-22000-third-death-confirmed?lite
which comes from NBC news.
I would like to redirect you and the rest of our readers to http://www.cdc.gov/hantavirus/hps/prevention.html
which I think puts the issue in better perspective rather than pure hysteria.
Furthermore the CDC states: What are hantaviruses?
Hantaviruses are a group of viruses that may be carried by some rodents. Some hantaviruses can cause a rare but deadly disease called hantavirus pulmonary syndrome. The disease is called HPS for short.
You state that - "In 2011, half of the 24 U.S. hantavirus cases ended in death. But since 1993, when the virus first was identified, the average death rate is 36%, according to the CDC."
Sounds like the Virus quite common and found everywhere?
The problem is, in my humble and quite possible totally ignorant view, there doesn't seem to be a reasonable protection from it. You are playing lottery by entering the park during the outbreak.
Iíll add from http://www.npr.org/templates/story/story.php?storyId=160615768
that states Yet the risk of getting these scary-sounding diseases is small. With the right precautions, you can still enjoy spending time outdoors. And that helps fight much more common threats to your health ó obesity and too little exercise. http://www.healthmap.org/news/rare-hantavirus-discovered-two-yosemite-vacationers-82312
This article further scares visitors by stating that the problem started in a campsite. This is not the case at all. In fact no one camping has contracted the virus.
Now, I do not know about others, but I've traveled the world over (including dozen U.S. national parks), and it never occurred to me to pack a bottle of bleach with me. Let alone a manual titled: "How to Recognize Mouse Droppings And Urine."
Donít worry those specific cabins are now closed. You will not get it in you 54 foot motor home-unless you let lots of mice in and they have time to poop. I didnít know it was dangerous to swim under the waterfall. On TV people do it all the time so it must be safe. Besides this is a Park just like Disneyland except there are no theme characters. If anything goes wrong I can always sue the government and get my money back.