Increased diphtheria cases in migrant reception centres in Europe

ECDC conducted a risk assessment regarding the overall risk posed by the reported cases of diphtheria in the EU/EEA for broader communities and specific populations exposed to migrants’ reception centres. 

In its recent report, ECDC estimates an overall very low risk for the broader population in the EU/EEA, considering the probability of infection and the impact of the disease. Given the estimated high diphtheria, tetanus, pertussis (DTP) immunisation coverage in the EU/EEA countries, ranging from 91% to 99% for the first dose (DTP1), out of three doses for a full vaccination course, and from 85% to 99% for the third dose (DTP3), the probability of individuals residing in the community to develop the disease is very low. Nevertheless, the possibility of secondary infections in the community cannot be excluded and severe clinical diphtheria is possible in unvaccinated or immunosuppressed individuals. 

Regarding the individuals residing, working, or volunteering in migrant centres, there is a moderate probability of exposure to diphtheria bacteria. Exposed unvaccinated or immunosuppressed individuals could face a severe outcome following a diphtheria infection. However, the impact of the disease for individuals with a complete diphtheria vaccine schedule is considered to be low.   

Diphtheria is a disease caused by bacteria. It can assume respiratory or non-respiratory forms and may affect various parts of the body, including the skin. People infected with the diphtheria bacteria may have no symptoms, but they carry the bacteria and are able to infect others. Diphtheria is caught by coming into contact with droplets from the respiratory tract of an infected person – particularly spread by coughing or sneezing. If the disease affects the skin, it can be spread by coming into contact with the wounds or lesions of an infected person.  

Successful treatment of diphtheria involves a rapid administration of diphtheria antitoxin equine (DAT) in combination with antibiotic treatment.  

To mitigate the further spread of disease in migrant centres and the community, countries are encouraged to put in place early detection, prevention and treatment measures, in accordance with national guidelines, as follows: 

• Checking the diphtheria vaccination status of newly arrived migrants, and providing diphtheria vaccination boosters or the complete course, as needed; 

• Isolating confirmed or suspected cases with respiratory diphtheria, and placing contact precautions for confirmed and suspected cases of cutaneous diphtheria; 

• Providing information and instructions to clinicians and health service providers to migrant centres regarding the possibility of diphtheria among migrants as well as travellers returning from endemic areas for the rapid identification and isolation of possible cases, sampling and testing; 

• Ensuring that all personnel working in reception centres for migrants have their vaccination status up to date; 

• Identifying, testing and monitoring close contacts; providing antibiotic prophylaxis and vaccination to close contacts; and inquiring about migratory routes, residence periods in migrant camps or overcrowded accommodations where diphtheria transmission may have occurred; 

• Enhancing surveillance, ensuring timely reporting to competent authorities, and verifying the national availability of laboratory diagnostics. 

As universal immunisation against diphtheria remains the only preventive measure which is effective against the disease, ECDC encourages EU/EEA countries to implement key actions in order to achieve the highest levels of protection, such as:  

• Strengthening routine immunisation programmes; 

• Identifying and reaching out to the unvaccinated or partially vaccinated population;  

• Ensuring the provision of booster vaccination doses to the adult and elderly population;  

• Promoting and monitoring equity of access to vaccination against priority diseases such as diphtheria, poliomyelitis and measles, particularly for vulnerable population groups such as migrants, refugees and asylum seekers;  

• Continuing to provide immunisation advice to people travelling to diphtheria-endemic countries; 

• Developing and rolling out training and information programmes for vaccine providers and vaccine receivers to improve vaccine acceptance;  

• Ensuring that clinicians have the knowledge required to promptly recognise and treat diphtheria; regularly assessing the level of access to DAT.