The encounter histories file is formatted according to the INP format and can (after changing the file ending fro .txt. to .inp) be imported to the software E-Surge that was used for the analysis. The encounter histories file contains no variable headings. The file contains two columns. The first column contains the encounter histories, which include information about each of the 21 occasions. Each occasion shows the type of encounter (0 = no encounter, 1 = encountered at Kalken, 2 = encountered elsewhere, 3 = recovered dead) The second column shows the number of individuals, which had that encounter history. For data selection criteria etc., see main paper.