True statement regarding diphtheria is
Toxin production is influenced by the concentration of iron in the medium. The optimum level of iron for toxin production is 0.1 mg/l, while a concentration of 0.5mg/l inhibits the formation of the toxin. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 240
It can be diagnosed by demonstration of antibodies by ELISA
Immunisation prevents carrier state
Treatment of contacts is not indicated
Iron has critical value in the production of toxin
Bacteriology