Since the first patient at the Warsteiner hospital on the 9th of August were 865 legionella occurrences registered in Germany. This is an increase by 25 percent in comparison to the previous year with 654 legionella occurrences. The number of occurrences ranges significantly by the federal state. The highest number of occurrences was registered in Nordrhein-Westfalen with a total number of 166 occurrences especially in the county Soest. Most of the legionella occurences spreads out in the southwest corner of Germany in contrast with just a few occurrences in northeast of Germany. But there are also some concentrations in Berlin and Hamburg.

The legionella outbreak in Germany reminds on the historical John Snow map about the cholera outbreak in London. An increasing detailing of data beginning from an overview of Germany, federal states, counties until the private residents can help to discover the distribution and investigation of legionella occurrences and potential sources. Discovering the sources is the most challenging part in both cases. In the case of John Snow it was a public water pump on the Broad Street while in the second it was an evaporation factory in the industry sector of Soest.