In 2021, 11 cases were reported in the UK, where the majority of the population was vaccinated against diphtheria during their childhood. The infection affects the nose, throat, and sometimes the skin, and can be fatal if not treated promptly.

The outbreak comes amid criticism of the government over the conditions under which it hosts people crossing the English Channel in small boats to reach Britain. Many of them were detained for days or weeks at Manston, a disused airport in south-east England, currently used as a processing centre. Last month there were up to 4,000 people at the venue, which is designed for a maximum capacity of 1,600 people.

A few weeks ago, a man who was being held in Manston became ill and died shortly thereafter in hospital. The diphtheria PCR test came back positive, although Immigration Minister Robert Jenrick said authorities were awaiting postmortem results to determine cause of death.

Thousands of migrants from around the world travel to northern France every year in hopes of crossing the canal to England. There has been a marked increase in the number of people trying to travel on rafts and small boats since authorities restricted other access routes.

So far this year, more than 40,000 people have arrived in Great Britain after making the perilous journey through the English Channel. Throughout 2021, 28,000 migrants arrived, while in 2020 only 8,500.

To prevent the crossing, the British government has announced controversial plans to send people arriving in small boats to Rwanda in an attempt to undermine the business plans of smuggling organizations.

Critics say the plan is immoral or practical, and has already been challenged in court.