Bayesian maximum clade-credibility trees of the Slovenian subtype B epidemic. Defined major clusters (n ≥ 10 patients) are highlighted in blue and small clusters (n = 2–4 patients) in green. The branches of the Slovenian sequences are colored according to the patients’ characteristics: (A) Country of infection: blue = Slovenia, red = abroad, yellow = unknown; (B) Gender: red = male, blue = female; (C) Mode of HIV-1 acquisition: yellow = homosexual contact, red = heterosexual contact, blue = injection drug use, teal = vertical transmission, green = unknown; (D) Timing of infection: blue = long-standing infection, red = recent infection, yellow = unknown. The branches of the control sequences are depicted in black. The rings are set at 5-year intervals with the outer circle starting at the sampling time of the latest sequence (2012.97).