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—Differences between contact persons and recruits in the sample.
Note. The orange area indicates the day of participation. A participant (P) was asked to report the number of contacts from the preceding day (dark purple area). The light purple area indicates contacts met 2–14 days before the participation day. Participants were asked to invite 4 recruits (Rs). A participant could invite a recruit (R) met either the preceding day or preceding 2–14 days.
