It isn’t just the Islamic terrorists that Europe has to worry about, but diseases that had long been eradicated in advanced western countries.
From the CDC:
During June 9–September 30, 2015, five cases of louseborne relapsing fever were identified in Turin, Italy. All 5 cases were in young refugees from Somalia, 2 of whom had lived in Italy since 2011. Our report seems to confirm the possibility of local transmission of louse-borne relapsing fever.
Louseborne relapsing fever (LRF) was once widely distributed in all geographic areas, including Europe and North America, occurring in association with poverty and overcrowding. In Europe, it virtually disappeared after World War I in parallel with improved living conditions that led to substantially decreased body lice infestations in humans (1). Currently, LRF is reported mostly from Ethiopia and surrounding countries, where it is endemic (2): in this region, it is an extremely common infection with substantial mortality. The causative agent is the spirochete bacterium Borrelia recurrentis. In nature, the only relevant vector is the body louse, which feeds only on humans; no other reservoir for this infection is known (1,3). The incubation period is 3–12 days. We report 5 cases of LRF in refugees to Italy from East Africa that occurred during 2015.
Borrelia recurrentis is transmitted from human to human by the body louse Pediculus humanus humanus. Head lice, Pediculus humanus capitis, have been found to be infected, but their role as vector has not been established.
Italy has recently received large numbers of refugees from East Africa, particularly from Somalia. These refugees come from and travel through countries where B. recurrentis is endemic; along the way, they are often sheltered in crowded conditions with very poor hygienic facilities. Two of the patients reported here indicated that, while staying in Libya, they were held with many other persons in a close environment, and all refugees housed together reported severe itching.
Many of these refugees enter Italy through Sicily, from where they are sent to reception centers throughout the country. Some of these reception centers have grown to substantial size and now house a more stable population, with continuous input of new arrivals. In these conditions, local transmission can occur with a possible risk for epidemics: 2 of the 5 patients reported here were long-term residents in Italy, and they denied recent travel to Africa, so they probably acquired the infection while being housed in the same facilities as the newly arrived refugees. Although it is possible that they denied recent travel for fear of legal consequences, they are unlikely to have had the opportunity to travel out of Europe for economic reasons.