Figure 1.

Human immunodeficiency virus transmission network identified in Tijuana, Mexico, between 2004 and 2016. Polygons represent individuals, with the actual shape representing sex, and color representing sexuality. People who inject drugs (PWID) are signified with a red border. Lines connecting polygons represent inferred putative transmission links. Black arrow and dashed line indicate the identified cluster of 5 PWID seroconverters diagnosed in 2012 (n = 2) and between April and May 2016 (n = 3). Abbreviations: FSW, female sex worker; MSM, men who have sex with men; PWID, persons who inject drugs.