HOXD13 and scarlet fever: In contrast with the United Kingdom epidemic, the expansion of scarlet fever-associated emm12 lineages in North-East Asia has been directly linked to acquisition of two genetic elements: the tetM- and ermB-carrying multidrug resistance element ICE-emm12 (and its derivatives) and the prophage ΦHKU.vir, encoding SSA, SpeC and the DNase Spd1 (refs 4,15,56).