Corynebacterium diphtheriae is a gram-positive, non-sporulating, unencapsulated rod-shaped bacterium, often club-shaped. It is a facultatively anaerobic organism and is resistant to cold. Depending on the type of infection, the disease caused by this pathogen can take one of two main forms: skin diphtheria and respiratory diphtheria. Two other strains of the Corynebacterium can cause diphtheria: C. ulcerans and more rarely C. pseudotuberculosis.
In contrast to other Corynebacterium strains, Corynebacterium diphtheriae is exclusively transmitted from person to person. Infection with Corynebacterium diphtheriae usually occurs through droplet infection. However, infection is also possible via direct contact with skin diphtheria lesions (skin injury) and via materials that have come into contact with infected secretions. The bacterium produces a toxin, the diphtheria toxin. Only this is able to trigger the disease. The incubation period is two to five days, in rare cases up to ten days.
Skin (cutaneous) diphtheria: Cutaneous diphtheria often manifests itself after a minor injury, for example as a result of an insect bite or a small scratch. Skin lesions with a grey mucous coating may form.
Respiratory diphtheria: Initially, the symptoms are unspecific and flu-like, with fever and difficulty swallowing. As the disease progresses, hoarseness, difficulty in breathing, palate paralysis and swelling of the lymph nodes can occur. After two to three days, tonsillitis develops with a greyish-white or brownish mucous coating, which can spread to the larynx.
If infection is suspected, the patient must be isolated. Protective measures against droplet transmission (for example, disposable face masks) and basic hygiene measures must be implemented. Covering skin diphtheria wounds is important to prevent smear infections caused by the wound secretion. Suitable disinfection measures must be carried out in the patient’s environment. All objects that the infected patient has come into contact with must be disinfected. Thorough hand disinfection is essential. In addition, patients should only be treated by staff members with up-to-date vaccination protection.
In Germany, Switzerland and Austria, suspected infection, disease cases and resulting deaths from diphtheria must be reported.
Up to six months.
The required spectrum of activity against Corynebacterium diphteriae is: bactericidal.