Small boat crossings could be behind a sharp rise in cases of diptheria in the UK say scientists.

Investigations by the European Society of Clinical Microbiology and Infectious Diseases have attributed the sudden increase in numbers, being recorded both here and in Europe, to those arriving in the UK from countries where they may not have ever received a vaccination.

In England in 2022, 73 cases of diptheria were recorded, up from 12 the previous year while so far in 2023 there has been one further case.

The majority have been seen in young Afghan men and boys, says the research, who have arrived with an unknown vaccination history.

Health experts are now calling for better care for asylum seekers, including access to more thorough screening, in order to prevent future outbreaks.

So what is diptheria, who is at risk and what can be done to prevent it?

What is diptheria?

Diphtheria is described by the NHS as a 'highly contagious infection' that affects the nose and throat, and sometimes the skin.

Symptoms can include a grey-white coating that may cover your throat, nose or tongue, a high temperature, sore throat, swollen glands and difficulty breathing. It can also lead to blisters and other skin problems.

Diphtheria is spread by by coughs and sneezes, through close contact with someone who is infected or by sharing items with an infected person such as cups, cutlery or clothing.

How is it treated?

Antibiotics can be used to kill the diphtheria bacteria in someone who has developed an infection, while other medicines can be taken to stop the toxins produced by the bacteria harming the body.

Any wounds caused by diptheria also need thorough and regular cleaning.

Treatment, says the NHS, usually lasts between two and three weeks while any skin ulcers usually heal within two to three months but can leave a scar.

What is the concern?

In the UK babies and children have been routinely vaccinated against diptheria since the 1940s, which means that cases among the general population are extremely rare. While those who travel to other parts of the world where diptheria is circulating are advised to have a booster injection before setting off from the UK.

But in the last couple of years recorded cases of diptheria have been increasing both in the UK and in Europe, which scientists say are 'mostly linked to incoming migrants'.

Young Afghan boys, under the age of 18, make up 97% of the patients - but the UKHSA notes that this group could be over-represented thanks to 'greater clinical awareness' among that demographic.

Just over half (51%) of patients with diptheria have showed skin problems caused by the infection, which can include blisters on legs, feet and hands, and large ulcers, while 12% had no symptoms but had been picked up through either screening or contact tracing.

Researchers note people arriving from countries where there is a lack of vaccination is partly to blame while there are also signs, they say, of 'evident transmission' among those who have travelled through migrant facilities.

In November last year a sudden and 'robust' screening programme had to be put in place at a number of facilities including Manston in Kent after concerns about outbreaks among asylum seekers.

How can diptheria be prevented?

Because of a successful vaccination programme that routinely immunises babies and children in the UK, the risk to the wider public from any diptheria outbreak is said to be extremely low.

Researchers at the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) have also been keen to point out that they have seen no forward transmission into European populations.

However experts say improved health screening of people arriving in small boats is now needed to ensure any future cases of diptheria do not spiral.

Those at the society say increased awareness among border officials and health staff - who are connected with processing people arriving in the UK - would also help to spot cases before they can be allowed to spread.