Fifth disease?

Can you get it easier if you are generally a dirty kid and/or could you spread it easier if you are a generally dirty kid? Again, my neighbors kids have fifth disease, and are generally unclean and unkept. They live in squalor, but come in our yard occionally and play with my kids. Should I be concerned my kids, especially my littlest (two yrs.) will get it? I know it's not that big of a deal and many children get it at daycare, but man, it's always something with my neighbors!