Sorry to hear about your uncles dog. I have had some experience with the parvo virus also, it's some scary stuff.
The virus mainly affects black & tan dogs, but it can affect other colored dogs as well. The dog has about a 50/50 chance of survival even if you take it to the vet immedietly, it's sad, but true. Parvo virus lasts up to 2 years anywhere that the infected dog and feces has been.
Nutter234 you asked if the virus can be spred from human to dog and the answer is yes. It only takes a very small amount of infected feces to transfer it to another dog. I had a sad incident with this. A past friend of mine owned an
animal shelter and one of the puppies had parvo and passed away. After completely disinfecting the kennel with bleach, washing ourselves and throwing away our clothes, just to be safe, three other puppies that were in a completely different area got the virus. I'm guessing that either me or my friend had some of the virus still on us even after being so careful.
Leo you said that you were maybe sounding over cautious? I don't think you are at all, parvo is a very scary disease and should be taken very seriously.
Nutter234, if you parents have their dogs shots up to date I wouldn't be too worried. I hope I have helped you and that everything goes well!
.. It might be a good idea to have your mom or dad gently ask them if they took it to any pet supply stores recently .. if so perhaps your mom or dad could contact the stores owners/mgmt so they can disinfect the store floors with bleach to avoid spreading the disease to other animals, also I hope their vet told them that it would be a good idea to wait at least 6 months before they get another puppy or allow any dogs in their home or they could be at risk for getting parvo also since the puppy was in the house & the parvo virus is in their home... Also they need to wash everything the puppy could have contaminated especially it's crate with bleach to kill the virus. 
Leo and 
Proud Coastie Sister!! 
My brother is in Virginia at FT school !!
