Globally, there were 8,500 diagnosed incident cases of the vaccine-preventable disease, diphtheria, in 2022, according to the World Health Organization (WHO). Diphtheria is a highly contagious, sometimes fatal, infection that affects the nose, throat, and skin. Patients with diphtheria present with fever; a grey coating in their mouth, throat, and across their tongue; a sore throat; difficulty swallowing; and breathing through the mouth. Symptom onset generally occurs within two days of initial infection through close contact with an infected individual or contact with particles transmitted through coughing and sneezing. In the 1930s, the diphtheria toxoid vaccine was launched globally, and in the 1940s, it was incorporated into routine immunisations alongside tetanus toxoid and the pertussis vaccine. At this time, there were 60,000 annual cases per year on average in the UK, with 4,000 deaths. Since the vaccine’s launch, diphtheria has been almost completely eradicated in developed countries. However, in developing countries where vaccine coverage is lower, outbreaks still occur.
The UK Health Security Agency reports that since June 2022, there has been an influx of cases of diphtheria among asylum seekers in the UK, with 18 cases reported in October and 27 cases reported in November. These cases have mostly been identified in the southeast region of England. In 2023, cases continued to arise, with some cases reported among pupils in a school in Luton at the beginning of December suggesting that transmission is still occurring among the unvaccinated population.
According to GlobalData epidemiologists, 92% of one-year-olds received three or more doses of the diphtheria vaccine in the UK in 2022, and 83% of three-year-olds have received the recommended four or more doses. However, vaccination coverage is expected to have declined during the Covid-19 pandemic. The WHO said that “from a global perspective recovery is on the horizon: in 2022 diphtheria-pertussis-tetanus (DTP) immunisation coverage almost recovered to 2019 levels. But the dip during the pandemic could leave a significant number of children susceptible to infection”. As such, it is vital that those who missed out on vaccinations during the pandemic and vulnerable populations (like asylum seekers) are offered booster doses or are educated on how to identify the symptoms and reduce the transmission of the infection to prevent larger-scale outbreaks from happening.