Diphtheria: migrant health guide
Advice and guidance on the health needs of migrant patients for healthcare practitioners
Main messages
The main messages are:
- diphtheria is a notifiable disease in the UK
- healthcare professionals have an important role to play in early recognition, isolation and treatment of suspected cases particularly amongst new arrivals and in settings where there is a higher risk of transmission.
- all cases are notifiable on clinical suspicion, including both respiratory and cutaneous forms of the infection – if you suspect a case, contact your local UK Heath Security Agency (UKHSA) health protection team
- diphtheria may present with respiratory symptoms and/or skin lesions. Respiratory presentations may be more common than expected in some migrants compared to the general UK population due to low vaccination rates. Many migrants have experienced long journeys prior to reaching the UK and often have poor skin integrity. C. diphtheriae has been found to colonise or infect long standing wounds, and there is often co-infection with other organisms such as Group A Streptococcus or Staphylococcus aureus
- all new arrivals should have their immunisation status checked and they should be brought up to the date with any vaccines they have missed or where their vaccination status is uncertain
- staff and healthcare workers involved in the care of recent arrivals should ensure they are up to date with their immunisations as per the UK schedule
Background
Diphtheria is an acute bacterial disease caused by the Corynebacterium species, C. diphtheriae and C. ulcerans. The World Health Organization reported that in 2024 there were approximately 25,146 diphtheria cases worldwide and the case fatality rate of diphtheria can be 30% for unvaccinated individuals, without proper treatment.
Diphtheria was once one of the most feared childhood diseases in the UK, with more than 61,000 cases and 3,283 deaths in 1940. However, following the introduction of mass vaccination, this was dramatically reduced, with only 38 cases and 6 deaths reported by 1957. National surveillance for toxigenic diphtheria is well established and between 1986 until 2023 there have been 233 toxigenic diphtheria cases in England and Wales with the annual number of cases varying from one to 87. Cases in recent years have been linked to foreign travel (C. diphtheriae) or to pet ownership (C. ulcerans).
Since June 2022, there has been a rise in toxigenic C. diphtheriae cases among asylum seekers in Europe and the UK. An outbreak of toxigenic diphtheria was reported among migrants in Europe in June 2022 and cases were seen in those arriving by small boats to the UK. The most common presentation was with cutaneous diphtheria, but respiratory presentations were also seen including a small number of cases with classical respiratory diphtheria with a membrane. Most cases diagnosed in England had arrived very recently and all were considered to have acquired their infection during their journey to the UK. Despite higher arrivals of asylum seekers by small boats in 2024 compared with 2022 and 2023, the level of risk of diphtheria appears to have reduced.
Symptoms
The incubation period for diphtheria is usually 2 to 5 days, but may be longer, with reports of incubation lasting up to 10 days. Respiratory symptoms and signs include:
- presence of sore throat
- fever
- adherent greyish membrane (bleeds when manipulated or dislodged) of the tonsils, pharynx, or nose (but noting a membrane may not always be present)
- other presentations: endocardial, optic, conjunctival, genital, laryngeal
Cutaneous symptoms:
- chronic non-healing sores or shallow ulcers
- dirty grey membrane, eschar, slightly raised
- usually on exposed limbs (legs)
As the disease is increasingly rare, most clinicians will not have encountered a case before and therefore may miss the clinical diagnosis. Clinicians should have a high index of suspicion for diphtheria in individuals presenting with compatible symptoms. Cases among migrants should be classified according to the case definitions in the supplementary national guidance noting the probable case definition has been expanded in this population (November 2022).
Due to low vaccine uptake reported in this population, the complex health needs of many residents and their mixing patterns, accommodation settings for migrants may be considered high risk for infectious diseases, including diphtheria.
Transmission
The most common mode of transmission of C. diphtheriae is droplet spread from a person with respiratory diphtheria or direct contact with cutaneous lesions or infected secretions (respiratory or cutaneous).
Testing
Appropriate swabs should be collected for all clinically suspected cases of diphtheria irrespective of clinical presentation and before starting treatment with antibiotics (see national guidance):
- nose and throat swabs should be taken for all suspected cases (including screening for respiratory carriage in cutaneous cases)
- skin swabs of wounds and lesions (if present)
- where a membrane is present, swabs from underneath the membrane or a piece of membrane
Diphtheria is a notifiable disease in the UK. If a case is diagnosed, contact your local UKHSA health protection team.
Treatment
In line with national guidance, all clinically suspected cases of diphtheria who present with respiratory symptoms and/or large cutaneous lesions (that is, greater than 2 cubic centimetres) should be promptly assessed by a clinician with advice from an infectious diseases specialist, for treatment with diphtheria anti-toxin (DAT).
Treatment with DAT should not be delayed and should be undertaken in a hospital setting. Management should be based on clinical assessment, even in the absence of laboratory confirmation and where there is no alternative diagnosis, particularly in those who have received antibiotic prophylaxis.
Refer to section 2.6.4 and 2.7 of the national guidance for information on the administration of antibiotics. A small number of multi-drug-resistant isolates have been reported in the European literature and local laboratories have been advised on minimum requirements for antibiotic susceptibility testing. Advice on further antibiotic therapy should be sought from the local microbiologist in the event of treatment failure or failure to clear carriage of the organism.
For guidance on immunisation of cases refer to section 2.6.5 in the diphtheria public health guidance.
Prevention and control
The most important aspects of preventing and controlling diphtheria are immunisation and infection prevention and control.
Immunisation
An immunisation history should be taken from all migrants When their immunisation status is uncertain or incomplete they should be brought up to date as per the UK schedule. UKHSA have guidance to support healthcare professionals with immunisation assessments.
All staff and healthcare workers involved in the care of recent arrivals should have their immunisation status reviewed and catch-up immunisations arranged if their status is uncertain or incomplete (as above).
Infection prevention and control, including the appropriate use of personal protection equipment
Guidance on the management of suspected cases, their close contacts and their environment may be found in the supplementary guidance for diphtheria cases and outbreaks in asylum seeker accommodation settings.
Resources
- Supplementary guidance for cases and outbreaks in asylum seeker accommodation settings
- Public health control and management of diphtheria in England: 2025 guidelines
- Skin lesions in newly arrived migrants: recognising and managing infections of public health importance
Information about diphtheria in English and other languages is available through the public health resource library.
Updates to this page
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Revised guidance.
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Rebranded page to UKHSA. No change to content.
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First published.