“…There has been a tendency in many quarters to deprecate the use of the terms gravis, mitis and intermedius for the different types on the grounds that these terms are misleading since mild or trivial cases of gravis infection are observed on the one hand and severe and fatal mitis infections on the other (15,36,109). No claims that all gravis diphtheria is severe and all mitis diphtheria is mild have ever been made.…”