Virus Spell

 
Prerequisite(s): None
 
Benefit: Any non damaging spell that targets a single creature can be modified by this feat. The affected creature becomes a carrier and spreads the spell effect by touch. Each creature it touches must save or become a carrier as well. The maximum number of creatures affected is the caster level squared. A spell modified by this feat takes a spell slot 4 levels higher.
 
Source: Mongoose Ultimate Feats