Does your husband have Amalgam
(which are mercury) fillings? If so, this may be causing the constant systemic fungus. If he has no mercury fillings, you might want to look into heavy metal chelation. If he has mercury fillings, it would be wise to take them out and then chelate. The other thing to possibly check is thyroid function and adrenal function, which could be depressed from metals or toxins.
The biggest challenge is to get to the root cause and fix that instead of treating symptoms.
It is good to take Vitamin C and other toxin removers.