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You might have read recently in the daily and medical press that there has been an outbreak of diphtheria among asylum seekers in England. Even though refugees are often young, physically fit males, they can have complex health needs after their long journeys, such as untreated communicable diseases. Since June 2022 there has been an increase in diphtheria cases, and as of December 2022 62 cases of diphtheria had been confirmed, with half of the cases being cutaneous. Before mass vaccination, 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.

Figure 1 Corynebacteriæ diphtheriæ 
Source: CDC
This image is in the public domain and thus free of any copyright restrictions. Use of this image does not constitute this blog’s endorsement or recommendation by the U.S. Government, Department of Health and Human Services, or Centers for Disease Control and Prevention.

Diphtheria is caused by the non-sporing, non-encapsulated, and non-motile Gram positive bacillus Corynebacteriæ diphtheriæ and Corynebacteriæ ulcerans. Respiratory diphtheria presents with a pharyngitis that often will be associated with a visible greyish membrane and enlarged anterior cervical lymph nodes with perinodal swelling, causing the classic bullneck appearance. Laryngeal diphtheria can be associated with progressive hoarseness and stridor, while nasal diphtheria can present with uni- or bilateral discharge and crustiness. As diphtheria has become increasingly rare in the United Kingdom, thanks to a successful immunisation campaign, it’s not always instantly recognisable for clinicians.

Figure 2 Bullneck appearance

Source: CDC
This image is in the public domain and thus free of any copyright restrictions. Use of this image does not constitute this blog’s endorsement or recommendation by the U.S. Government, Department of Health and Human Services, or Centers for Disease Control and Prevention.

The incubation period for diphtheria is usually 2 to 5 days but may be longer. The commonest mode of transmission of C. diphtheriæ is via droplet spread from a person with respiratory diphtheria; prolonged close contact is usually required for spread.

Cutaneous diphtheria usually starts as a vesicular rash and then forms one or more clearly demarcated ulcer that can be covered in a blueish-grey membrane. Patients may have both cutaneous and respiratory disease.

Figure 4 cutaneous diphtheria 
Source: CDC
This image is in the public domain and thus free of any copyright restrictions. Use of this image does not constitute this blog’s endorsement or recommendation by the U.S. Government, Department of Health and Human Services, or Centers for Disease Control and Prevention.

Figure 3 respiratory diphtheria by User: Dileepunnikri is licenced under CC BY-SA 3.0 via Wikimedia Commons.

Swabs should be collected from patients and sent to a local diagnostic laboratory with appropriate clinical details.

All suspected cases have to be notified to the UK Health Security Agency. Patients might be referred to the local specialist infectious disease team for face-to-face assessment and review. Treatment options include diphtheria anti-toxin intravenously and macrolide antibiotics.

References

Knights, F; Munir, S (2022). Initial health assessments for newly arrived migrants, refugees, and asylum seekers. BMJ 2022;377:e068821 https://doi.org/10.1136/bmj-2021-068821 

British Medical Association (2022). Unique health challenges for refugees and asylum seekers. https://www.bma.org.uk/advice-and-support/ethics/refugees-overseas-visitors-and-vulnerable-migrants/refugee-and-asylum-seeker-patient-health-toolkit/unique-health-challenges-for-refugees-and-asylum-seekers (Accessed 19.01.2023)

UK Health Security Agency (2022): Infectious diseases in asylum seekers: actions for health professionals. https://www.gov.uk/guidance/infectious-diseases-in-asylum-seekers-actions-for-health-professionals (Accessed 19.01.2023)

UK Health Security Agency (2022): Public health control and management of diphtheria in England. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1117027/diphtheria-guidelines-2022_v17_111122.pdf (Accessed 19.01.2023)