Infectious agent: Corynebacterium diphtheriae
Description of illness: Diphtheria is a rare acute bacterial disease preventable through vaccination. Important sites of infection are the respiratory mucosa (respiratory diphtheria) and the skin (cutaneous diphtheria). Humans are the only known reservoir of the bacteria. The disease is transmitted from person to person by respiratory droplets or direct contact with respiratory secretions, discharges from skin lesions or, rarely, fomites. The onset of respiratory diphtheria is insidious and begins after an incubation period of 2-5 days (range 1-10 days). Initial symptoms of illness include sore throat, difficulty in swallowing, malaise, low grade fever and swollen glands in the neck. The hallmark of respiratory diphtheria is the presence of a tough, grayish-white pseudomembrane over the tonsils, the pharynx, or larynx.