Sweden is seeing an increase in the number of cases of Leishmaniasis, a rare parasite that can be fatal in certain serious cases, with researchers claiming a link between the rise of the disease and mass migration.

A study by the University of Lund examined the rise in cases with Sara Karlsson Söbirk, a doctor who specialises in infectious diseases, saying, “It’s still a very rare disease here, but the number of cases has more than doubled in the last ten years,” in a press release from the university on the study.

According to Söbirk, the number of cases of the parasite peaked in 2016, with 35 cases, with the physician noting it was “probably a direct consequence of the large refugee wave the year before, when most people who were sick were from Syria and Afghanistan.”

“It is likely that we will receive more cases in Sweden in the future and then it would be good if the health care system knows which patient groups they should be especially aware of,” she added.

The parasite, which can live for years within an individual without showing any signs of illness, is largely found in areas outside of Northern Europe with there being around 400,000 cases recorded worldwide every year, according to Söbirk, who said that so far researchers had “found only five cases in Sweden of the most serious form of the disease during the 23 years we looked at.”

Migrants Bringing Rare Diseases Strain Health Service https://t.co/xSLI0aOxG5 pic.twitter.com/pH0zYtfSCJ — Breitbart London (@BreitbartLondon) September 30, 2016

“The most common form of the disease in Sweden (93 per cent) is the skin form, cutaneous leishmaniasis, which often heals but can cause disfiguring scars on the face and on the arms and legs,” she said and advocated more research towards developing a vaccine for the disease.

Leishmaniasis is not the only rare disease to have been brought to Europe as a result of the migrant crisis which began in 2015. Several diseases thought almost wiped out in Europe along with rare ones from the Middle East have been shown within migrant populations with doctors in Germany warning about the problem in 2016.

Another parasite, scabies, has also been prominent among migrants in Paris living on the streets or squatting in buildings. The parasite even forced migrants occupying a university building Paris to leave after university staff began to become infected with the parasite as well.