Diphtheria is a bacterial (toxin-related) disease. It is an acute pharyngitis, acute naso pharyngitis or acute laryngitis with a pseudomembrane formation in the throat.

Infectious Agent: Corynebacterium diphtheria

Reservoir: Man

Incubation Period: 2 to 5 days or may be longer

Mode of Transmission:

• By droplets spread through sneezing, coughing and close personal contact.

Period of Communicability:

• May last for 2 to 3 weeks
• May be shortened in patients with antibiotic treatment
• Diphtheria transmission is increased in schools, hospitals, households and in crowded areas.


• Immunization of infants with 3 doses of DPT (at ages 6 weeks old, 10 weeks old and 14 weeks old).