Um, if you're talking about the Hantavirus, there's actually very few cases of it worldwide. And the only species of mice to have ever been known to carry Hantavirus is the Deer mouse, but there's still only a handful of cases where people have been infected. There are no known cases of House mice ever contracting Hantavirus and/or spreading it.
And according to Washington State's Department of Health, "Pets, snakes, and predators don’t become infected and can’t spread hantavirus infection to people or other animals." So I don't know what the pets you speak of got ill and died from, but apparently, it wasn't the Hantavirus.
And according to the PDF file from this site, as well: http://www.cfsph.iastate.edu/FastFac...ntavirus_F.pdf
Says the same thing; and the only way pet mice and rats can contract it is through a bite from the infected Deer mouse, or by inhaling the disease through the infected Deer mouse's excretions.
For your benefit, VanillaRat, here's a site that shows a drawing of what Deer mice droppings look like, so you can distinguish whether you actually have deer mice running around, and thus the risk of infection, or if you just have House mice around, which don't carry the Hantavirus: http://www.ehso.com/ehshome/hantavirus_mousesigns.htm