Several methods are listed here
http://www.wikihow.com/Remove-Blood-Stains
and more here.
http://www.howtocleanthings.com/how-to-clean-blood.htm
I have had great success with both meat tenderizer (has the same enzymes as spit and none of the nasty stuff :shock: ) and club soda (not together). You do plan to wash all that spit out of the quilt, right? :wink: :D