Fig. 1

Baseline transmission routes (a) to which transmission routes 1–3 (b–d) have been added; arrow signifies the direction of transmission. Note: Man 1 ①; Man 2 ②
Baseline transmission routes (a) to which transmission routes 1–3 (b–d) have been added; arrow signifies the direction of transmission. Note: Man 1 ①; Man 2 ②