infectious diseases
Diphtheria
Introduction
Diphtheria is an acute pharyngeal or cutaneous infection caused mainly by toxigenic strains of the gram-positive bacillusCorynebacterium diphtheriaeand rarely by other, less commonCorynebacteriumspecies. Symptoms are either nonspecific skin infections or pseudomembranous pharyngitis followed by myocardial and neural tissue damage secondary to the exotoxin. An asymptomatic carrier state also exists. Diagnosis is clinical and confirmed by culture. Treatment is with antitoxin and penicillin orerythromycin. Childhood vaccination and booster doses should be routine. Corynebacterium diphtheriaeusually infect the nasopharynx (respiratory diphtheria) or skin (cutaneous diphtheria). Diphtheria is now rare in the US and other high-income countries because childhood immunization is widespread. Susceptibility in high-income countries has also increased because booster immunization rates in adults are declining. Diphtheria is endemic in many countries in Asia, the South Pacific, the Middle East, Eastern Europe, Venezuela, Haiti, and the Dominican Republic. Outbreaks in Indonesia, Thailand, Vietnam, Laos, South Africa, Sudan, and Pakistan have occurred since 2011 (travel information about diphtheria is available at theCenters for Disease Control and Prevention [CDC] web site for travelers' health). Diphtheria may be present in returning travelers or migrants from countries where diphtheria is endemic. 