Variables used for the study of the Infectious environment (INF-E).

The past exposure of patients was studied for measles, mumps, varicella, influenza like illnesses, and acute diarrheas during different exposure windows. It was abstracted using two methods: “cumulative” is the total of the regional incidences around the case during the window. “high” is the mean of the 10 largest regional incidences to which the patients or the VC were exposed. See Material and Methods, and S2 File for details on the measures of environmental infectious exposures.