Anorexia is not a spiritual attack and can not be cured by fasting, especially not water fasting. Fasting and prayer are not cures for Ebola as there is no magical medic in the sky responding to these as forms of communication. Are you saying that Ebola has been engineered to destroy a certain population? Or were you referring to other specific diseases? I am curious and am hoping I am not within a target population.
I do think Water Fasting is great for many things, like obesity and atherosclerosis, but not anorexia.