Since about 150 years one assumed that the leprosy didn't exist in Germany any more. But then the illness appeared in the district of Memel in the middle of the 19th century.
In 1896 Robert Koch (the discoverer of the tuberculosis bacillus) during his researches on-site stated that the illness had to have been brought in from Russia, Norway and Sweden. He observed that Memel's city was spared by the leprosy completely, however. On the other hand, the leprosy was noticed nearby the Russian border and later in the northern districts of Memel and in the suburbs of the town, too.
With his report about the infection Koch develops a real genre picture of the time. He talks about the fact that the population lives and would sleep in narrow rooms together. Infected garments were used by healthy humans. Remarkably often Koch was informed about, that one after another person who became sick had slept together in the same bed. On the other hand Koch noticed that there would be single people who completely were immune to leprosy. Koch reported about a woman as an example for this, who has cared for her husband and four adult children and lost to the leprosy after each other within 20 years. Koch nevertheless found her at the examination completely healthily. It similarly was with a man who had leprosy in his family for 12 years, and who shared the bed with his leprously wife for years.