A different Treponema pallidum strain distribution was found among samples derived from men who have sex with women and women from this study as compared with the same population worldwide. The Treponema pallidum strain distribution among men who have sex with women were similar to the strain distribution men who have sex with men. The most prevalent strains and percentage of strains belonging to the Nichols lineage are similar to previous studies in Amsterdam focusing on men who have sex with men. [ABSTRACT FROM AUTHOR]