(Table 1). The place of exposure was defined by the
clinician if he/she had confidence that the illness was
acquired in that place given the duration of the incuba-tion period and/or known endemicity patterns or if the
region was the only one visited by the patient. Medi-cal data included the final physician-assigned diagnoses
according to a standardized list of 556 possible etiologi-cal diagnoses of diseases, including death that were also
categorized under 21 broad syndromes, as previously
described.
13
When necessary, several final diagnoses
were assigned to one patient. The travel duration, a
proxy for duration of exposure, was measured as the
duration of the most recent travel. The time to presen-tation was calculated as the time between the end of
travel and presentation at a GeoSentinel clinic. These
two variables were evaluated for travelers seen after
travel only.