Cause: Toxigenic strains of the bacterium Corynebacterium diphtheriae.
Illness and treatment: Diphtheria is a toxin-mediated disease. Infections are primarily in the respiratory tract (respiratory diphtheria) and the skin (cutaneous diphtheria); infections in mucosal sites outside the respiratory tract are rare. Respiratory diphtheria is an upper-respiratory tract illness characterized by sore throat, low-grade fever, with a strongly adherent membrane in the upper airway, including the tonsils, nasopharynx, and can extend to the larynx and trachea, causing airway obstruction. Inflammation of the cervical lymph nodes and of the soft tissue in the neck can occur and is a sign of severe disease. Cutaneous diphtheria is usually mild, characterized by shallow ulcers and sores that can be difficult to distinguish from other skin conditions. Cutaneous diphtheria can be a source for spreading both respiratory and cutaneous diphtheria to susceptible people. Treatment is with antitoxin, antibiotics, and supportive care.
Sources: Humans are the reservoir of C. diphtheriae. Transmission is through respiratory droplets when an infected person coughs or sneezes, as well as through contact with discharge from their eyes, nose, throat, or skin lesions. An asymptomatic carrier is a person who carries bacteria without experiencing symptoms. Carriers can maintain the spread of bacteria within a population.
Additional risks: Travelers to areas with low vaccination rates are at higher risk of diphtheria infection, especially for those who are unvaccinated or undervaccinated.
Prevention: Vaccination is the most effective way to prevent diphtheria. Respiratory and hand hygiene can help to prevent the spread of the infection.
Purpose of Reporting and Surveillance
- To assist in the diagnosis of cases
- To assure early and appropriate treatment with diphtheria antitoxin and antibiotics
- To identify and evaluate contacts and recommend appropriate antibiotic prophylaxis and/or immunization to prevent further spread of the disease
- To alert public health authorities to the presence of diphtheria cases and the possibility of additional cases developing in the area, a particular concern given the large number of susceptible adults
Legal Reporting Requirements
- Health care providers and health care facilities: immediately notifiable to local health jurisdiction
- Laboratories: immediately notifiable to local health jurisdiction; submission required – isolate within 2 business days; submission on request – specimen associated with positive result, within 2 business days.
- Local health jurisdictions: immediately notifiable to the Washington State Department of Health (DOH) Communicable Disease Epidemiology (CDE) at 877-539-4344 or 206-415-5500.