Best resource for treatment is going to be his Dr. I do not know that much about MC, go into the expert community and use the search field and look for MC, the Dr's do a great job of explaining transmission.
I agree - first off he needs to go and be seen and find out what is going on. no need to avoid sex at this point since you two have already been together for 6 months.
if this is mc, they can remove it for him. odds are this is something else going on.
grace