Fig. 2
Schematic illustration of how high sexual network connectivity can enhance transmission of bacterial vaginosis associated bacteria (BVAB - depicted in red). In the low connectivity network (right), the BVAB are trapped in the A-B relationship until this breaks up when woman A can transmit the BVAB to her new partner (C). Man B may then also transmit BVAB to his new partner (D) but if the gap between his old and new partner exceeds the duration of penile colonization for BVAB (time between T2 and T3) then he will not transmit to his new partner. In the high connectivity network (left), the BVAB does not need to wait for the A-B partnership to end and can, without impediment, spread to other individuals connected via sexual partnerships (Squares-men, Circles-women, Red/Gray nodes-BVAB−/non-BVAB -containing genital microbiome, Gray lines-sexual partnership active on first day of the month; see text for further details)