The causative organism is a bacterium called Treponema pertenue a subspecies of Treponema pallidum that causes venereal syphilis . However yaws is a non-venereal infection .

致病微生物是一种 被 称作 雅司 螺旋 体的细菌， 它是引起性病梅毒的梅毒螺旋体的一个亚种。