Diphtheria

Corynebacterium diphtheriae

Downloads Services
Changed on: 10.04.2019
Icon
caption
Diptherie-Erreger

Classic diphtheria is a serious infection that could end terminally without adequate treatment. Cases of diphtheria are registered only sporadically in Western countries. However, the disease is endemic to many other world regions, such as the Far East and East Asia, South America and Africa.

Corynebacteria are Gram-positive, facultative anaerobic, non-sporulating, rod-shaped bacteria that can have tapered or clubbed ends (“coryne”: Greek for club). The majority of representatives of this group are opportunistic pathogens (i.e. only pathogenic under specific conditions). Corynebacterium diphtheriae, the pathogen causing diphtheria, is the most important bacterium of this group. However, only its toxin producing strains can cause diphtheria.

More information
caption
Diptherie-Erreger

Classic diphtheria is a serious infection that could end terminally without adequate treatment. Cases of diphtheria are registered only sporadically in Western countries. However, the disease is endemic to many other world regions, such as the Far East and East Asia, South America and Africa.

Corynebacteria are Gram-positive, facultative anaerobic, non-sporulating, rod-shaped bacteria that can have tapered or clubbed ends (“coryne”: Greek for club). The majority of representatives of this group are opportunistic pathogens (i.e. only pathogenic under specific conditions). Corynebacterium diphtheriae, the pathogen causing diphtheria, is the most important bacterium of this group. However, only its toxin producing strains can cause diphtheria.

More information

Transmission

Humans are the only reservoir of Corynebacterium diphtheriae.

Diphtheria is chiefly transmitted through the air in the form of droplets or via direct contact with respiratory secretions or wound exudates. In addition, vomit or contaminated food (unpasteurised milk) or items could play a role in spreading the disease.

 

 

Symptoms

The classic entry points for C. diphtheriae are the respiratory tract and the skin.

Skin diphtheria is mainly found in tropical regions and manifests itself as badly healing skin ulcers, covered by dirty, grey membranes.

Diphtheria of the respiratory systems starts following an incubation period of two to five days causing a sore throat, tiredness, cervical lymph node enlargements and subfebrile body temperatures. Adherent pseudo membranes form in the nasopharynx (Greek: “diphtheria”, meaning leather), covering the throat and one or both tonsils, expanding over the remaining tissue of the soft palate and bleeding heavily when removed. The colour of these membranes could be white, dirty grey, green or black.

These pseudo membranes could also affect the larynx, trachea and bronchial tubes, leading to severe symptoms, such as hoarseness, shortness of breathing or cyanosis, which could become life-threatening when not treated immediately (intubation). Toxin production is followed by conduction disorders, mainly in the heart and the central nervous system. These disorders manifest as heart arrhythmias, cardiac conduction disorders of various levels of severity, as well as acute heart failure with circulatory collapse. The toxins damage the motor nerves primarily. On rare occasions, sensor nerves are also affected, causing a so-called “stocking-glove” pattern peripheral neuropathy.

Therapy

Treatment must begin as soon as possible (following preliminary clinical diagnosis). It is carried out simultaneously with antibiotics and diphtheria antitoxin (diphtheria serum). Diphtheria antitoxin is currently not available in Austria. The National Reference Centre for Diphtheria knows only one manufacturer that produces diphtheria antitoxin at present.

Full basic immunisation and regular follow-ups usually make disease progression less severe. Should there be complications, life-saving measures (intubation, circulatory support, treating heart arrhythmia) are required.

Hygiene Measures

Patients should be isolated even at clinical suspicion to prevent further infections. More information can be found in the diphtheria folder (see download).

 

 

Diagnosis

The method of choice is to cultivate the pathogen from clinical examination material. Swabs from inflamed areas (noses, throats, tonsils, wounds) and the membranes removed are suited best for this.

If no wound swabs can be taken, it is recommended to try and gain aspirates from the edge of the wound. Moreover, other materials (blood, urine) can be used in coordination with the laboratory, depending on the type of clinical suspicion. Once the culture has been grown, it is essential to detect toxin production for making a certain diagnose.

 

 

 

Prevention

Prevention should already begin with children. It encompasses active immunisation with a toxoid vaccine, an inactive diphtheria toxin.  The vaccine for children is available as a combination vaccine together with tetanus, whooping cough and poliomyelitis. Immunisation should be followed-up every 10 years (e.g. in combination with tetanus).


x