| − | '''Diphtheria''' is a [[bacteria]]l [[disease]] marked by the formation of a false membrane, especially in the throat, which can be fatal. | + | '''Diphtheria''' is a [[bacteria]]l [[disease]] marked by the formation of a false membrane, especially in the throat, which can be fatal.<ref>http://www.cdc.gov/vaccines/about/terms/glossary.htm#d</ref> |