My son has become very ill for a month now and diagnosed as having cryptospordium parvum, but has been unresponsive to medication's and treatment's. Unable to eat, go to school, spend any significant amount of time out of bed etc. Is anyone liable for his contracting this?

This is caused by protozoal infection from drinking contaminated water. This particular protozoa does not filter out during normal water purification. make sure you boil all water used for drinking and cooking. Allow the water to cool before using. A water filter with "absolute 1 micron" filtering can be used instead of boiling water.
He most likely qualifies for Home Health provision of IV fluids and total parental nutrition.