Diphtheria, a disease which had almost disappeared from Europe but of which several grouped cases appeared in 2022, presents specific symptoms.
- Diphtheria cases jumped in Europe in 2022. France recorded 30.
- The disease, caused by a bacterium, is transmitted mainly from person to person, either through droplets of saliva or skin wounds.
- Experts call for maintaining “good vaccination coverage” and educating caregivers about this disease to deal with the rise in cases.
While vaccination had succeeded in stopping the circulation of diphtheria in Europe, health professionals observed an increase in the number of patients in 2022. These are mainly cases imported from countries where the bacterium of the genus Corynebacterium, responsible for this highly contagious disease is still circulating. But what do we know about this disease which had largely disappeared from France since the Second World War?
Diphtheria: characteristic symptoms to spot
Diphtheria can be caused by several bacteria of the genus Corynebacterium, in particular Corynebacterium diphtheriae and Corynebacterium ulcerans. “Certain strains of these bacterial species can carry the tox gene (which codes for diphtheria toxin) and therefore are capable of producing diphtheria toxin. This toxin is responsible for serious clinical manifestations”explains theInstitut Pasteur on its website.
The disease is transmitted mainly from person to person, either through droplets of saliva or skin wounds. It is characterized by an infection of the upper respiratory tract. The most severe forms can lead to paralysis of the central nervous system or of the diaphragm and throat, resulting in death from asphyxiation. The incubation period of the disease is 2-5 days.
One of its most characteristic symptoms is the presence of whitish “false membranes” on the tonsils and palate. “Diphtheria angina is the usual form of the disease. It is characterized by pharyngitis, fever, neck swelling and headache”specifies the Pasteur Institute.
There is also a cutaneous form of diphtheria. The false membranes then appear on a pre-existing wound or skin ulceration.
Diphtheria in France: a rather exceptional situation
The alarm bell was sounded during the European Congress of Clinical Microbiology and Infectious Diseases, organized from April 15 to 18, 2023. The number of diphtheria patients increased sharply on European soil in 2022. There were 30 cases in France, 118 in Germany, 69 in Austria and 52 in Switzerland.
“It is a rather exceptional situation”said Dr Sylvain Brisse, director of the National Reference Center for Diphtheria and director of research at the Institut Pasteur in Figaro. He specifies : “However, we cannot speak of a European epidemic, because there have been no transmissions to the general population: these cases remain limited to people arriving from abroad, in a situation of vulnerability, often requesting asylum”.
If the causes of this wave of diphtheria are not fully identified, the poor vaccination coverage of the countries of origin of the patients (mainly Afghanistan and Syria) is one of the most advanced hypotheses by specialists. In his study, Dr. Brisse identified four different strains of the disease. Some – a minority – were resistant to macrolides, “antibiotics used in patients allergic to amoxicillin or penicillin”. He therefore calls for maintaining “good vaccination coverage” and to educate caregivers about this disease.
