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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
True statement regarding diptheria is :
assistant
The correct answer is  Diagnosis of Diptheria
i. Isolation by culture :
Swabs are inoculated on :
– Loeffler’s serum slope (growth is rapid) : for rapid diagnosis.
– Tellurite blood agar (growth is delayed but it is particularly important in isolation of bacilli from convalescent, contacts, carriers) : Selective media.
– Blood agar (for differentiating staphylococcal and streptococal pharyngitis). convalescent, contacts, carriers) : Selective media.
– Blood agar (for differentiating staphylococcal and streptococal pharyngitis).
ii. Demonstration of toxicity of isolated strain :
In vivo test – done by infected broth emulsion of culture subacutaneously and intracutaneously into guinea pigs.
In vitro test – Elek’s gel precipitation test and tissue culture test on agar overlay of cell culture monolayer.
Control of Diptheria
i. Cases – Antitoxin + penicillin or erythromycin
Park 19/e, p 137
ii. Carriers – Erythromycin
iii. Contacts –
a. When primary immunization or booster dose was received within the previous 2 years.

No further treatment.

b. When primary immunization or booster dose was received more than 2 years ago.

Only a booster dose of diphtheria toxoid.

c. Non immunized close contacts :

Prophylatic penicillin or erythromycin
1000 - 2000 units of diphtheria antitoxin
Active immunization against diphtheria.

iv. Community – Only effective control is by active immunization with diphtheria toxoid of all infants with subsequent booster doses every 10 years thereafter.
Remember : Vaccine ‘being a toxoid’ is not directed against organism and hence immunization does not prevent carrier state which is due to organism not due to toxin.